The Traveling Engineers’ Association
To Improve The Locomotive
of American Railroads
Examination Questions and Answers
For Firemen for Promotion and New Men for Employment
Copyrighted by W. O. Thompson, March, 1911
Revised January, 1919
|EXAMINATION QUESTIONS: FIRST SERIES
| AIR BRAKE QUESTIONS
|EXAMINATION QUESTIONS: SECOND SERIES
| AIR BRAKE QUESTIONS
| OIL BURNING LOCOMOTIVES
|MECHANICAL EXAMINATION: THIRD SERIES
| COMPOUND LOCOMOTIVES
| WALSCHAERT AND BAKER-PILLIOD VALVE GEARS
| SOUTHERN VALVE GEAR
| FEDERAL REGULATIONS
| PYLE-NATIONAL ELECTRIC HEADLIGHT
| SCHROEDER HEADLIGHT
| "BUDA-ROSS" ELECTRIC HEADLIGHT
| DUPLEX LOCOMOTIVE STOKER
| AIR BRAKE QUESTIONS
It is the policy of railroads to employ firemen
who will in time become competent locomotive
engineers. This requires that a man should have at
least a common school education, good habits and
be in good physical condition. He should be alert,
with good reasoning faculties and a man of sound
judgment. Having these qualifications, advancement
will come to those who are conscientious in discharging
their duties and who devote some of their leisure
hours to study.
As an aid to this end, and that the railroad companies
may derive the highest efficiency from the
man employed as a locomotive engineman, a code
of questions is given him, and it is expected that
the preparation necessary to correctly answer the
questions will indicate how well he has progressed.
The list of questions is also intended as a guide
to the matters on which he should be correctly
informed, both during his term of service as a
fireman and for future promotion to engineer.
When a man is first employed as a fireman he will
be given a list of questions on which he will be
examined at the end of the first year; having passed
this examination successfully he will then be given
the examination questions for the following year;
[Pg 4]having passed this examination satisfactorily, he will
be given a third and final set of examination questions
on which he will be examined before being
promoted to engineer. All these examinations will
be both written and oral. The third year examination
for promotion will be before the General Board of
Examiners. At any of these examinations, if he fails
to pass 80 per cent. of the questions asked, another
trial, not less than two months and not more than six
months later, will be given him to pass the same
examination; if he fails to pass by a percentage of
80 per cent. he shall be dropped from the service.
Where the examinations consist of both air brake
and machinery, the candidate must pass 80 per cent.
in each to be successful.
Firemen passing the third and final series of
questions will be promoted in the order of their
seniority as firemen, except that those who pass on
the first trials shall rank, when promoted, above those
who passed on the second trials.
Engineers employed who have had service on
other roads, will be required to pass the third series
of questions before entering the service.
It is not expected that the man will pass these
examinations without assistance, and in order that
he will understand the use of locomotive and air
brake appliances properly, he is expected to go to
the Master Mechanic, General Foreman, Road Foreman
or Traveling Engineer, also Air Brake Inspector
or Instructor, or any other official, and ask them for
[Pg 5]such information as may be required on any of the
questions or on any points in connection with the
work. He is not only invited, but also urged to do
this, as the more knowledge of his business a man
possesses, the better will be the results obtained. He
will have ample time to study each set of questions;
there is no doubt that with a reasonable amount of
study each week, supplemented with close observation
of the working of the locomotive, the information
necessary to answer satisfactorily the entire list of
questions can be easily mastered in the time given. In
regard to breakdowns, it is advised that he carefully
inspect each breakdown or disabled engine that
comes to his notice, see where the parts have given
way and in what manner the work of blocking up
it done. It is not expected that all the breakdowns
which may happen to a locomotive will occur on the
engine that he is with; therefore it is good practice
to observe how other men care for these breakdowns.
In connection with these examinations the work done
by the fireman during the year and how the work
compares with that of other firemen in the same
class of service will be carefully noted; his record
as to the use of coal, supplies and attention to duty
will be taken into consideration.
It is hoped that he will give everything in detail
the consideration it merits and realize fully that it
is by looking after the little things that a man succeeds.
It should be borne in mind that by filling well
the position he holds he becomes entitled to the confidence
that makes better positions possible. It is[Pg 6]
understood that those who conduct the examination
may ask any question or questions bearing on any
subject of this examination, in order to determine
how well the persons being examined understands the
subject. A mere memorized answer will not be sufficient.
The full meaning of each answer must be
1. Q. What do you consider essential for your
success in regard to the use of ?
A. I deem it essential to my success to be as
economical in the use of fuel and supplies as is consistent
with the work to be performed, exercising
good judgment in my work, harmonious co-operation
with my engineer, and showing a willingness to learn
and practice the best methods in my work.
2. Q. What are the fireman's duties on arrival
at enginehouse previous to going out on a locomotive?
A. He is required to examine the bulletin board,
guards on water and lubricator glasses; try gauge
cocks to find true water level; then examine grates,
ash-pan, flues and fire-box. Put fire in proper shape;
see that a proper supply of firing tools, water, coal,
oil and waste are provided, that all lamps and markers
are filled, cleaned and in proper condition; and
to perform such other duties as may be required by
the engineer to assist him in getting the engine in
3. Q. What pressure is indicated by the steam
gauge? What is meant by atmospheric pressure?
A. The pressure per square inch inside of the
boiler. Atmospheric pressure is the pressure represented
by the density of the atmosphere in pounds
per square inch, which is at sea level 14.7 pounds.
4. Q. On what principle does a steam gauge
A. The steam gauge pointer is actuated by a
flattened or bent round tube to straighten itself under[Pg 8]
the pressure of steam against the water inside of
tube. The gauge pointer receives movement from
suitable mechanism connected with the tube.
5. Q. What is the source of power in a steam
A. Heat is the source of power in all steam
engines. It is necessary to have fuel and water.
When fuel is burned, the water coming in contact
with the hot sheets evaporates and becomes steam,
which is then used in the cylinders to force the pistons
back and forth.
6. Q. About what quantity of water should be
evaporated in a locomotive boiler to the pound of
A. From five to seven pounds of water. For
example, one gallon of water weighs eight and one-third
pounds, therefore 100 pounds of coal should
evaporate from sixty to eighty-four gallons of water.
7. Q. What is steam, and how is it generated?
A. Steam is water in the condition of a vapor
and is generated by heating the water above the
8. Q. What is the purpose of the water gauge
glass and gauge cocks?
A. To indicate the level of water in the boiler.
9. Q. What would indicate to you that the boiler
connections of water gauge glasses were becoming
A. The up and down movement of the water in
the glass would become slow and inactive, or it would
not register correctly with the gauge cocks.[Pg 9]
10. Q. At what temperature does water boil?
A. At atmospheric pressure, which is 14.7 pounds
at sea level, water boils at 212 degrees Fahrenheit;
the temperature, however, increases as the pressure
under which the water is boiled increases. At 200
pounds boiler pressure the temperature would be
388 degrees Fahrenheit.
11. Q. What is carbon?
A. Carbon forms the greatest part of all kinds of
coal; the higher the per cent. of carbon, the higher the
grade of coal.
12. Q. What is the composition of bituminous
A. It is composed of carbon about 75 per cent.
and many gaseous substances, as is shown by its
burning with a large flame and much smoke. Anthracite,
on the contrary, is nearly pure carbon and
burns with a small flame.
13. Q. What is combustion?
A. Combustion or burning is a chemical process,
it is the action of fire on inflammable substances and
is the union of the oxygen in the air with the carbon
in the fuel; this is called rapid combustion. Slow
combustion is the decaying of wood or iron by the
14. Q. Is air necessary for combustion?
15. Q. About how many cubic feet of air is
necessary for the combustion of a pound of coal in
a locomotive fire-box?
A. About 300 cubic feet of air must pass through[Pg 10]
the grates and fire for complete combustion of one
pound of coal.
16. Q. Why must air be heated before combining
A. Air, like coal and its gases, must be heated
before they will unite to form what is known as
combustion and so as not to reduce the temperature
of the fire-box below the igniting point of the gases.
17. Q. Why is it necessary to provide for combustion
a supply of air through the fuel in the
A. In order to supply the oxygen necessary for
18. Q. What is the effect upon combustion if too
little air is supplied? If too much air is supplied?
A. If too little air is supplied, combustion is not
complete, and only one-third as much heat is obtained.
If too much air is supplied, combustion is
complete; but the excess air must be heated, resulting
in a lower temperature. If twice the amount of air
required for complete combustion be supplied, the
temperature of the fire-box will be about one-half as
19. Q. Give a practical definition of the igniting
A. In all ordinary combustion there is a definite
temperature, called the ignition or kindling temperature,
to which combustible substance must be heated
in order that it may unite with the gas in supporting
the combustion. The burning substance must not
only be heated up to the kindling temperature, but it
must be kept as high as this temperature, or combustion
will cease.[Pg 11]
20. Q. State why such temperature is necessary
and at what place in the fire-box it is most required.
A. The center is the hottest part of the fire-box.
There is a much lower temperature in the fire-box at
the sides and end sheets, due to the water on the
opposite sides of the sheets being of a lower temperature
than the fire-box; therefore if we get as high
a temperature as possible at the side and end sheets,
we will increase the steam-making efficiency of the
boiler. The gases which are liberated from the coal
as soon as it becomes heated must attain a temperature
of about 1,800 degrees Fahrenheit, known as
the "temperature of ignition," before they will unite
with air which must also be heated up to that point.
21. Q. How is draft created through the fire?
A. Exhaust steam escaping through the stack reduces
the pressure in the smoke-box below the pressure
of the atmosphere outside, therefore the air tends
to force itself into the smoke-box through all openings;
with everything in good condition, the easiest
and largest passage for it is through the grates and
other openings into the fire-box and from it through
the tubes into the smoke-box and up the stack.
22. Q. Is smokeless firing practicable?
A. Yes, but it is necessary in order to obtain good
results that boiler and fire-box be in good condition,
coal broken to the proper firing size; then, with the
hearty and intelligent co-operation of both engineer
and fireman, smokeless firing is both economical and
23. Q. In what condition should the fire be in
order that the best results may be obtained from the
combustion of the coal?[Pg 12]
A. The fire should be as light as the work being
done by the engine will permit, evenly distributed
over the grates and free from clinkers.
24. Q. How should the blower be used?
A. A blower should be used very lightly, being
careful not to draw too much air into the fire-box and
through the flues, especially when fire is being cleaned
or thin on grates.
25. Q. What is the result of opening the fire-door
when the engine is working steam?
A. It will cause a cooling effect in the fire-box
and is liable to start the flues leaking.
26. Q. What is the effect of putting too many
scoops of coal on a bright fire? Is this a waste of
A. It has the effect of temporarily deadening and
cooling the fire, causes emission of quantities of black
smoke, as only a limited amount of gas can be burned
in a fire-box at a time; all in excess of that amount
escapes from the stack and is a waste of fuel.
27. Q. What effect has the fire upon a scoopful
of coal when it is placed in the fire-box?
A. The heat from the fire drives the gases from
the coal and they are ignited by the hot flame as they
pass over the bright fire; the coke which is left burns
where it is.
28. Q. In what condition should the fire be to
consume these gases?
A. A bright white coke fire, almost incandescent.
29. Q. What is the temperature of the fire when
in this condition?
A. It must not be less than 1,800 degrees Fahrenheit
to consume the gases liberated from the coal,[Pg 13]
and it only requires from 750 to 900 degrees Fahrenheit
to burn the coke that remains on the grate; as
coke burns from the outside, less heat is required to
30. Q. How can the fire be maintained in this
A. By adding coal to the fire in small quantities,
spreading it over the grate surface and no faster than
it is burned.
31. Q. What is black smoke? Is it combustible?
A. Black smoke consists of small particles of
carbon suspended in the gases of combustion and
indicates incomplete combustion. Black smoke is not
combustible, it is like lampblack and cannot be
burned after having been produced. The production
of it can be prevented by suitable arrangements and
32. Q. Should the gas not burn in the fire-box,
will it burn after it enters the flues? Why?
A. Gas will not burn only a short distance in the
flues of a boiler, as the water absorbs the heat so
quickly that the temperature of gas is lowered below
the igniting point.
33. Q. What is the effect on the flow of air
through the fire from opening the door? What on
the burning of the gases? What on the flues and
sheets of the fire-box?
A. When the furnace door is opened, the flow of
air through the grate is stopped in proportion to the
amount that passes through the door. The vacuum
will be filled from the quickest source and the door
is closer than some parts of the grate. The gases
mix with the air from the door and pass out through[Pg 14]
the flues; no combustion takes place, as the air is not
hot enough to unite with the gas. The flues and
sheets of the box will be caused to leak on account
of the rapid contraction.
34. Q. Can the firing be done more effectively if
the water level is observed closely?
A. Yes, in order to know how much water there
is in the boiler and whether it is necessary to hurry
the fire; if the boiler is full, it is possible to prevent
the pops opening by delaying the fire.
35. Q. How should the fire and water be handled
in starting from a terminal or other station?
A. The steam pressure should be near the maximum
and there should be sufficient water in the
boiler to last until such time as the fire is burning well
so that the pressure will not be reduced when water
is put into the boiler. There should be a moderately
heavy bed of fire well burned and distributed evenly
over the grates. After the fire is burning well, the
injector should be started lightly; the feed being
gradually increased so as not to cause any decrease
of steam pressure.
36. Q. What is the purpose of a safety valve on
a locomotive boiler? Why are more than one used?
A. A safety valve is used to limit the maximum
pressure in the boiler by opening and allowing steam
to escape. More than one safety valve are used as
additional protection against excessive pressure; one
is set at the maximum pressure and the others are set
at two or three pounds above the maximum pressure.
37. Q. What is usually the reason for steam being
wasted from the safety valve? What can be done to
prevent this waste?[Pg 15]
A. Careless firing, careless running. Both engineer
and fireman work in harmony to obtain the best
38. Q. What is the estimated waste of coal for
each minute the safety valve is open?
A. About fifteen pounds. The estimated waste
of steam when an engine pops equals every second all
the heat obtained from a quarter pound of coal.
Safety valves usually remain open about half a minute,
resulting in the loss of about eight pounds of coal.
39. Q. What should be the condition of the fire
on arriving at a station where a stop is to be made?
A. On approaching the station where a stop is to
be made, firing should be stopped far enough back to
allow the carbon gases to be consumed before the
throttle is closed, so there will be little or no black
smoke from the stack and yet have sufficient fire that
it will not be necessary to feed the fire again if a short
stop is to be made until the train is started and the
engine cut back or nearly to the running cut-off.
40. Q. How should you build up the fire when
at stations in order to avoid black smoke?
A. Put in small quantities of coal at a time, have
the door slightly open and have the blower on lightly;
good judgment must be exercised by the fireman.
41. Q. Why is it that if there is a thin fire with a
hole in it the steam pressure will fall at once?
A. Because too much cold air is drawn into the
fire-box and through the tubes, retarding combustion
and cooling the fire-box and tubes.
42. Q. If the injector is to be used after throttle
is shut off, how should the fire be maintained?
A. A sufficient quantity of coal should be placed[Pg 16]
on the grates to maintain the maximum steam pressure
and the blower used to keep the fire burning
43. Q. What would be the result of starting a
heavy train or allowing drivers to slip with the fire
too thin on the grates?
A. The fire would be pulled off the grates and
into the tubes, leaving the fire bed full of holes and
some of the fire remaining on the grates turned over.
Large quantities of cold air would be drawn in, resulting
in a rapid decrease of temperature and pressure.
The tubes would possibly start leaking and
the fire would be in such condition that it could not
be built up properly in a long distance. Possibly the
grates would become clogged up with green coal—an
excellent opportunity for forming clinkers. In
this condition, the engine would fail to make steam
for the entire trip.
44. Q. Where should the coal, as a rule, be
placed in the fire-box?
A. As a rule, more coal is burned along the sides
and in the corners than in the middle of the
grates; the fire should consequently be kept somewhat
heavier along the sides and corners than in the
45. Q. How is the fire affected by and what
A. A clinker shuts off area of grate surface according
to its size, and thereby shutting off that much
of the air supply and interfering with proper combustion.
Clinkers are caused by firing too heavy in spots,
which prevents sufficient air passing up through these
spots and allows the coal to run together, melting the
ash, and sand; running a hoe or slash bar through[Pg 17]
the fire will bring the points of melted sand together,
causing a clinker.
46. Q. How can you best avoid their formation
and dispose of them?
A. Light firing and occasionally moving the grates
lightly is the best preventive. When once formed,
they should be removed if possible by firing around
and burning them out.
47. Q. How can you explain the slower burning
of the coke and how understand the proper manner
of supplying fresh coal?
A. The gases of coal are lighter than air and will
pass away whether consumed or not. The slow burning
of the coke is due to the fact that it burns from
the outside only. When a fire reaches a white or
incandescent heat it indicates that the gases are
burned and a fresh supply of coal should be added;
this is to be done as light as the service performed by
the engine will permit.
48. Q. When and for what purpose is the use of
a rake on the fire bed allowable?
A. The rake should be used on the fire very
seldom, because raking the fire bed tends to form
clinkers, especially when the rake is plunged down
through the fire to the grate. It may be used when
necessary to rake the fire lightly when on the road
for the purpose of breaking the crust, which may be
found as a consequence of too heavy firing.
49. Q. Within what limits may steam pressure
be allowed to vary, and why?
A. Pressure should not be allowed to vary more
than five pounds from the maximum for the reason[Pg 18]
that too much expansion and contraction will take
place, which many times is the cause of flues leaking,
cracked or broken side sheets and stay bolts.
50. Q. Has improper firing any tendency to cause
the tubes to leak? How?
A. Yes; if the pressure is not regularly maintained,
the fluctuations of temperature cause constant
contraction and expansion to take place. If the
fire is not carried level, but is carried heavy in some
parts of the fire-box and light in others, holes will be
worked in, cold air drawn through, lowering the temperature,
chilling the tubes and causing leaks. Carrying
the fire too heavy in some places, causes clinkers
to form. If the door is open too long, too much cold
air is drawn over the fire, causing the tubes to leak.
51. Q. What do you consider abuse of a boiler?
A. Careless or improperly supplying water to the
boiler, improper firing or allowing steam to vary from
high to low pressure, causing unnecessary expansion
52. Q. Does the stopping up of flues affect the
steaming capacity of the engine?
A. Yes; obstructed flues reduce the heating surface,
reduce the steaming capacity of the engine, and,
as a rule, result in causing the flues to leak. They
also cause an increase of speed of the gases through
the remaining flues and a poor steaming engine.
53. Q. What causes honeycomb over the flues?
A. Honeycomb on flues is usually caused by the
draft through the fire picking up the sulphur and
molten clay which is in a molten and sticky condition[Pg 19]
in the fire; as it passes on its way to the stack, some
of it strikes the flue-sheet and sticks or passes through
the flues, clogging up the netting in the front end.
54. Q. How would you take care of a boiler with
leaky tubes or fire-box, and why?
A. Keep a bright, clean fire, especially up next
to the flue-sheet, and as even a pressure of steam as
possible and not use the blower any stronger than is
55. Q. Why is it very important that coal should
be broken so that it will not be larger than an
ordinary sized apple before being put into the fire-box?
A. In order to get rapid and complete combustion,
coal should be broken into small pieces; this aids
combustion by exposing a larger surface to the flame
and can be fired more economically and better results
56. Q. Should rapid firing be practiced?
A. No; it should not be practiced for the same
reason that heavy firing is wrong. A few moments
should intervene between each shovelful to allow the
fresh coal to get to burning and to maintain the high
temperature in the fire-box.
57. Q. When and why should you wet the coal
on the tender?
A. Coal should be wet for the purpose of cleanliness
to keep dust from flying and because moderately
wet coal gives out more heat for the reason that there
is not so much fine coal drawn through the tubes. It
should be wet as often as necessary to accomplish
these purposes.[Pg 20]
58. Q. What are the advantages of a large grate
A. Greater heating surface, lighter fire and more
complete combustion are possible with the larger grate
surface, because a larger amount is burning at one
time at a slower rate of combustion.
59. Q. Why are grates made to shake, and how,
when and where should they be shaken?
A. For the purpose of breaking any clinkers that
might form and to shake out all refuse from the
grates. The best time to shake grates is when throttle
is closed, as there is no exhaust to carry the unconsumed
gases and sulphur through the flues into
the front end, which is liable to choke or clog up
netting and cause a steam failure. Grates should not
be shaken while passing over bridges, near lumber or
hay yards or through prohibited territory.
60. Q. Do you understand that coal furnished
represents money invested, and should be fired economically
and not allowed to fall out of the gangway?
A. The fuel of locomotives is property and represents
money invested the same as do buildings, rolling
stock, etc.; careless or inefficient firemen who
waste fuel destroy property as certainly as though
cars or engines were smashed up. The coal should
be carefully raked off the deck and in from the
gangways; it should not be allowed to fall, as it is
wasted and dangerous to people near the track. The
deck should be kept clean for greater comfort and
61. Q. Is is objectionable to fill the tanks too full
of coal or overflow tank at standpipes or water tanks?[Pg 21]
A. It is. Tanks filled too full of coal are dangerous
and a great waste of coal, as the jar when running
will cause a part of it to fall off; water overflowing
from tanks results in washing away the ballast
and in cold weather freezes over the tracks.
62. Q. What are the duties of a fireman on
arrival at the terminal?
A. Different roads have different assigned duties
for the firemen to perform. They should leave the
cab, boiler head, oil cans and deck in a clean condition,
boiler full of water, enough fire and steam,
so that the hostler will not be required to put in fuel
while the engine is in his charge; should know that
throttle valve is securely closed, reverse lever in center
of quadrant, cylinder cocks open, and if equipped
with independent brake, it to be applied; in fact, it is
an excellent opportunity for a mechanical officer to
judge the ability of the fireman and future engineer.
63. Q. Is the engineer responsible for the fireman's
conduct while on duty and for the manner in
which the fireman's duties are performed?
A. He is. The fireman is under the direction of
the engineer, and the fireman's duties are to be performed
in accordance with the engineer's instructions.
64. Q. What is the duty of the superheater
damper, and how does it operate?
A. The duty of the damper is to control the flow
of gases through the large flues, thereby protecting
the units which are contained therein from being
overheated after throttle is closed. The position of
damper when the engine is not working steam, is
65. Q. What will be the effect on the steaming
of the engine if the damper does not open properly?
A. Engine will steam poorly for the reason that
there will be no draft through the large flues. The
steam will not be superheated because heated gases
cannot come in contact with superheated units contained
in the large flues.
66. Q. How may steam failure be avoided in case
the damper fails to operate?
A. The counterweight may be tied up, thereby
opening the damper.
1. Q. What is an air brake?
A. A brake operated by compressed air.
2. Q. How is this air compressed?
A. By an air compressor on the locomotive.
3. Q. Name the different parts of the air brake
as applied to the locomotive.
A. The air compressor, compressor governor, automatic
and independent brake valves, distributing
valve, triple valve, auxiliary reservoir, brake cylinders,
main reservoir, air gauges, angle cocks, cut-out cocks
and the necessary piping.
4. Q. What is the purpose of the main reservoir?
A. It is used for storing a large volume of air for
the purpose of promptly charging and recharging the
brakes. Where the engine is equipped with either the[Pg 23]
E. T. or L. T. type of brakes, main reservoir air is
used to supply the air to the brake cylinders on the
5. Q. What other appliances use main reservoir
A. It is used in the operation of the power reverse
gear, sand blower, bell ringer, water scoop, air signal,
fire door, water sprinkler and other devices.
6. Q. What does the red hand on each of the air
A. The red hand on the large gauge indicates
main reservoir pressure; on the small gauge, brake
7. Q. What does the black hand on each of the
air gauges indicate?
A. The black hand on the large gauge indicates
the equalizing reservoir pressure; on the small gauge,
brake pipe pressure.
8. Q. What pressure is usually carried in the main
A. Ninety pounds in freight and 130 pounds in
passenger service. But where freight engines are
equipped with duplex compressor governor, the low
pressure top is adjusted to ninety pounds and the high
pressure top to 130 pounds.
9. Q. What pressure is usually carried in the
A. Seventy pounds in freight and 110 pounds in
10. Q. What must the air pass through in flowing
from the main reservoir to the brake pipe?
A. Through the automatic brake valve.[Pg 24]
11. Q. Name the different positions of the automatic
A. Release, running, lap, service and emergency
positions. The brake valve used with the E. T. and
L. T. equipment has still another position known as
holding position, which is located between running and
12. Q. Name the different positions of the independent
A. Release, running, lap, slow application and
quick application positions.
13. Q. How many kinds of triple valves are there
A. Two; plain and quick action.
14. Q. How is the automatic brake applied? How
A. The automatic brake is applied by a reduction
of brake pipe pressure, and is released by restoring
the brake pipe pressure.
15. Q. When the independent brake valve handle
is placed in application position, are the train brakes
A. No; only the brakes on the locomotive are
16. Q. What controls the pressure in the main
A. The compressor governor.
1. Q. What, in your opinion, is the best way to
fire a locomotive?
A. To carry a nice, level fire on the grate, or it
may be just a little heavier at the sides and front, so
the air cannot come through it near the sheets as
rapidly as in the center of the fire-box; always fire
as light as consistent with the work required, endeavor
to maintain a uniform steam pressure at all times,
and avoid unnecessary black smoke and a waste of
steam through the safety valves by the engine popping.
2. Q. What are the advantages of superheated
steam over saturated steam in locomotive service?
A. Saving in water; saving in fuel; increased
boiler capacity and a more powerful locomotive.
Superheated steam does away entirely with all condensation
in the cylinders, while saturated steam coming
in contact with passages in cylinder saddle and
walls of cylinders, is immediately cooled and in cooling,
a part of it is changed back into water which
affects the pressure and therefore its capacity to do
3. Q. How is the saving in water produced?
A. By the elimination of all cylinder condensation
present in saturated steam locomotives and the increase
in volume of a given weight of steam.
4. Q. How is the saving in coal accomplished?
A. Because there is less steam used to do the
same amount of work, there is less water evaporated[Pg 26]
and consequently less coal required to evaporate the
5. Q. How is the increased boiler capacity obtained?
A. A boiler will evaporate a certain amount of
water into steam and if part of the steam is lost by
condensation, only that remaining is available for running
the engine. Superheating eliminates the losses,
thereby increasing the available useful steam. Further,
superheating increases the volume of a given
weight of steam, thereby reducing the consumption
of steam required to develop a certain power and
consequently increases the capacity.
6. Q. How is a more powerful engine obtained?
A. By reason of the increased boiler capacity an
engine may be worked farther down before a steam
7. Q. What type of fire tube superheater is in
most general use in locomotive service?
A. The top header fire tube type, known as the
"Schmidt Superheater." A system of units located
in large flues through which the steam passes on its
way from the dry pipe to the steam pipes, and a
damper mechanism which controls the flow of gases
through the large flues.
8. Q. Describe the construction and location of
A. The header is a simple casting, divided by
partition walls into saturated and superheated steam
passages. It is located between the dry pipe and the
steam pipes, the same as the nigger head in a
saturated locomotive. The dry pipe is in communication
with the saturated steam passages and the[Pg 27]
steam pipes with the superheated steam passages and
these are in communication with each other through
the superheated units.
9. Q. Describe the construction of superheater
units and their connection to the header.
A. The units are composed of four seamless steel
pipes, connected by three return bends. Of the four
pipes, two are straight and two are bent upward and
connected to the header by means of a clamp and
bolt; one end of the unit is in communication with
the saturated steam passage and the other with the
superheated steam passage in the header casting.
10. Q. Trace the flow of steam through the top
header fire tube superheater.
A. When the engine throttle is open, saturated
steam passes through the dry pipe into the saturated
steam passage of the header casting. From this
passage it enters one end of the unit, passing backward
toward the fire-box, forward through one of the
straight pipes and the front return bend, backward
through the other straight pipe to the back return
bend, and forward through the bent pipe and upward
into the superheater steam passage of the header,
from which it enters the steam pipes and is carried to
the steam chest.
11. Q. What should be the position of throttle
valve when running a superheater locomotive?
A. The engine should always be run with as wide
open throttle as the conditions will permit, regulating
the steam admission to the cylinders according to
work to be performed.
12. Q. What should be the position of throttle
while drifting?[Pg 28]
A. The throttle valve should be kept slightly open
while drifting, so as to admit a small quantity of steam
in valve chamber and cylinder above atmospheric
pressure, to prevent the inrush of hot air and gases
which destroy lubrication, also to prevent excessive
wear to valve, cylinder and piston rod packing.
13. Q. How should the water be carried in boiler
of superheater locomotives?
A. As low as the conditions will permit, because
this practice reduces the tendency to work water over
into the dry pipe and units, as the superheater locomotive
will use one-third less water than the saturated
14. Q. What care should be exercised in lubricating
a superheater locomotive?
A. The supply of oil to steam chest should be
watched very closely by the engineer, he to know
that lubricator is feeding constantly and evenly over
entire division, and according to work performed.
15. Q. Describe the general form of a locomotive
A. A locomotive boiler is cylindrical in form, it
usually has a rectangular shaped fire-box at one end
and a smoke-box at the other, and flues extend
through the cylindrical part, and, like the fire-box,
are surrounded by water.
16. Q. How does the wide fire-box type of boiler
differ from the ordinary boiler, and what are its advantages?
A. The wide fire-box type of boiler is built so the
fire-box is above the frame and extends out over the
driving wheels. The advantages of this are to obtain[Pg 29]
a larger grate area in the same length of fire-box and
to give a slower rate of combustion per square foot
of grate surface. The deep fire-box is limited in width
to the distance between the frames, while the shallow
fire-box sets on top of the frames and between the
17. Q. Why have two fire-box doors been placed
in the large type of locomotive boilers?
A. For convenience of the fireman on account of
the greater width of the fire-box, so that coal can
easily be distributed to all parts of the fire-box.
18. Q. Describe a locomotive fire-box.
A. The modern form is a rectangular shaped
structure located at the back end of the boiler. It
has a door and is composed of two side sheets, a
crown sheet, a back sheet and a flue sheet from which
the flues extend to the smoke-box at the other end
of the boiler.
19. Q. To what strains is a fire-box subjected?
A. To crushing strains and to those of unequal
contraction and expansion.
20. Q. How are the sheets of a fire-box supported?
A. They are supported by staybolts screwed
through the inside and outside sheets with their ends
21. Q. In what manner is a crown sheet supported?
A. By crown bars or radial staybolts.
22. Q. What are the bad features about crown
A. They are hard to keep clean and frequently
cause crown sheets to become mud burned.
23. Q. What are the advantages of radial stayed
A. They are easier to keep clean and cheaper to
24. Q. How are the inside and outside sheets of
a fire-box secured at the bottom?
A. They are riveted to a wrought iron ring called
25. Q. Describe the ash-pan and its use.
A. It is a receptacle secured to the fire-box and
usually provided with dampers to regulate the flow
of air to the fire. It collects the ashes that drop from
the fire-box and prevents them from setting fire to
bridges or other property along the track. Engine-men
must know that ash-pan slide and hopper bottoms
are closed before leaving enginehouse.
26. Q. What is a "wagon-top" boiler?
A. It is a boiler that has the fire-box end made
larger than the cylindrical part to provide more steam
27. Q. Why are boilers provided with steam
A. To furnish more steam space and to obtain
dryer steam and to provide a place for the safety
valves, steam pipes, throttle valve and whistle.
28. Q. What must be the condition of a boiler to
give the best results?[Pg 31]
A. It must have good
and be clean
and free from mud or scale.
29. Q. What is meant by "circulation" in a
A. Free movement of the water, so that it may
come in contact with the heating surface and after
being converted into steam be immediately replaced
by a fresh supply of water.
30. Q. What would be the effect if a "leg" of
the fire-box became filled with mud?
A. There would be no water in contact with the
fire-box sheets and they would quickly become overheated
31. Q. What would be the result if the fire-box
sheets became overheated?
A. They would be weakened and forced off the
staybolts and an explosion would occur.
32. Q. Would it be advisable to put water into
a boiler after the sheets had become bare and red hot?
A. No. The fire should be killed at once.
33. Q. What effect has the stoppage of a large
number of flues?
A. The heating surface and draft are decreased
by just that much area.
34. Q. Why are boiler checks placed so far away
from the fire-box?
A. To introduce the water into the boiler at as
great a distance from the fire-box as possible. This
permits the water to become heated to a high tem[Pg 32]perature
before it comes in contact with the fire-box
and also improves circulation.
35. Q. What part of the boiler has the greatest
A. The bottom, because it is subject to the weight
of the water in addition to the steam pressure in the
36. Q. What are the advantages of the extension
A. To provide room for suitable draft and spark
37. Q. What is the purpose of a netting in a
smoke-box or front end?
A. To act as a crusher of all cinders and prevent
large cinders from passing out of the front end
to the atmosphere.
38. Q. What is the object of hollow staybolts?
A. To indicate when the staybolt is broken by
the escape of steam through the small hole in the bolt.
39. Q. What will cause the engine to tear holes
in the fire?
A. Working hard or slipping when the dampers
are open and the door closed, or too thin a fire.
40. Q. Name the various adjustable appliances in
the front end by which the draft may be regulated.
A. The exhaust nozzle, the diaphragm and the
draft pipes or petticoat pipe.
41. Q. What object is there in having the exhaust
steam go through the stack?[Pg 33]
A. To create a draft through the tubes and fire-box.
42. Q. How does this affect the fire?
A. The exhaust steam escaping through the stack
tends to empty the smoke-box of gases and produces
a partial vacuum there, atmospheric pressure
then forces air through the grates and tubes to refill
the smoke-box, and in this way the draft through the
fire is established and maintained.
43. Q. Explain what adjustments can be made
and the effect of each adjustment on the fire.
A. Larger or smaller nozzle tips cause less or
greater draft on the fire; raising or lowering the
draft pipes and diaphragm causes the engine to burn
the fire more at the rear or front end of the fire-box;
the size and position of the draft pipes increase the
draft through the top or bottom flues; the latter adjustments
should always be attempted before reducing
44. Q. What does it indicate when the exhaust
issues strongest from one side of the stack?
A. The stack, exhaust pipe or petticoat pipe are
out of plumb.
45. Q. What is the effect of leaky steam pipe
joints inside the smoke-box?
A. The engine will not steam freely.
46. Q. What causes "pull" on the fire-box door?
A. The partial vacuum in the front end; when
excessive it indicates dampers closed, fire clinkered
or insufficient opening for the admission of air under
the fire.[Pg 34]
47. Q. If upon opening the fire-box door you
discover there what is commonly called a red fire,
what might be the cause?
A. The grates may have become clogged with
ashes or clinkers so that sufficient air could not pass
through them to the fire.
48. Q. Is it not a waste of fuel to open the fire-box
door to prevent pops from opening? How can
this be prevented more economically?
A. Yes. This can usually be prevented by putting
the heater into the tank, or putting on the injector,
or by more careful firing.
49. Q. Describe the principle upon which the
A. The action of the injector is due first to the
difference between "kinetic" or moving energy and
"static" or standing energy; second, to the fact that
steam at a pressure travels at a very high velocity and
when placed in contact with a stream of water it is
condensed into water, and at the same time it imparts
enough velocity to the water to give it sufficient momentum
to overcome a pressure even greater than the
original pressure of the steam. By imparting this
velocity to the water it gives it sufficient energy to
throw open the check valves and enter the boiler
against high pressure.
50. Q. What is the difference between a lifting
and a non-lifting injector?
A. A lifting injector will create sufficient vacuum
to raise the water from the level of the tank. The
steam tubes in a non-lifting injector are different and
it will not raise the water, but merely force it into[Pg 35]
the boiler. A non-lifting injector must be placed below
the level of the water in the tank so the water
will flow to it by gravity.
51. Q. Will an injector work with a leak between
the injector and tank? Why? Will it prime?
A. A lifting injector will not work if the leak is
bad. It will not prime because the air admitted
through the leak destroys the vacuum necessary to
raise the water to the injector level. A non-lifting
injector will work, as the water will escape from the
pipe instead of air being drawn into it as with the
52. Q. If it primes well, but breaks when the
steam is turned on wide, where would you look for
A. Insufficient water supply due to tank valve
partly closed, strainer stopped up or tank hose kinked,
injector tubes out of line, limed up, or delivery tube
cut, or wet steam from the throttle.
53. Q. If it would not prime, where would you
expect to find the trouble?
A. Insufficient water supply, priming valve out of
order, or with the lifting injector the trouble might be
caused by a leak between the injector and tank.
54. Q. Will an injector prime if the boiler check
leaks badly or if it is stuck up? If the injector
throttle leaks badly?
55. Q. If steam or water shows at the overflow
pipe when the injector is not working, how can you[Pg 36]
tell whether it comes from the boiler check or the
A. Close the main steam valve at the boiler, that
will stop the leak if it comes from the injector throttle.
56. Q. Will an injector prime if primer valve
leaks? Will that prevent its working?
A. It will prime, but not as readily as with priming
valve in good condition. This will not prevent its
working, but it may waste some water from the
57. Q. Will an injector work if air cannot get
into the tank as fast as the water is taken out?
58. Q. If you had to take down a tank hose, how
would you stop the water from flowing out of the
tank that has the syphon connections instead of the
old-style tank valves?
A. Open the pet cock at the top of the syphon
before taking the hose down.
59. Q. Is any more water used when the engine
foams than when the water is solid?
A. Yes, very much more.
60. Q. How would you prevent injector feed
pipes or tank hose from freezing in winter when not
A. The steam valve should be slightly open to
permit a slight circulation of steam through the feed
and branch pipes. The heater cock should be closed[Pg 37]
and the drip cock under the boiler check or on the
branch pipe should be opened to insure a circulation
of steam through the branch pipe.
61. Q. How would you prevent the overflow pipe
from freezing with a lifting injector?
A. The overflow valve should be opened just
enough to permit a little steam to escape through the
overflow pipe to prevent it from freezing.
62. Q. Name the various parts of the injector.
A. The injector consists of a body supplied with
a steam valve, a steam nozzle, a primer, a combining
tube, a delivery tube, a line check valve, an overflow
valve, a water valve, and a lifting injector has a lifting
63. Q. What may be done if a combining tube
A. The steam valve bonnet may be removed and
the obstruction forced out with a piece of stiff wire,
or uncouple the delivery pipe from the injector and
unscrew and remove the tubes; the obstruction can
then be removed and the tubes replaced.
64. Q. How is the greatest injury done to a boiler
when cleaning or knocking the fire?
A. By excessive use of the blower drawing cold
air through the fire-box and flues.
65. Q. Why does putting a large quantity of cold
water into a boiler when the throttle is closed cause
the flues to leak? When is this most serious?
A. When steam is not being used there is not
much circulation of water in the boiler, and the water[Pg 38]
entering the boiler at about 150 degrees temperature
is heavier than the water in the boiler. The cooler
water will go to the bottom and reduce the temperature
in that part of the boiler and causing the flues
to contract in length as well as in diameter and this
has a tendency to pull them out of the sheet. This
will loosen them and cause them to leak. After the
fire has been knocked this tendency is much greater,
and for that reason cold water should not be put into a
boiler after the fire has been knocked out. Always
fill the boiler before the fire is knocked out.
66. Q. Is warm water in the tank of any advantage
in making steam rapidly?
A. Yes; careful experiments have shown that a
locomotive will generate one per cent. more steam
for every eleven degrees that the tank water is heated;
thus by heating the feed water in the tank from 39
degrees to 94 would effect a saving of five per cent.
67. Q. Then why not heat the feed water to the
boiling point (212 degrees)?
A. If the feed water is heated much above 100
degrees it will not condense enough steam in the injector
to cause it to work properly. Some injectors
will work hotter water than others. It would also
spoil the paint on the tank if heated to a much higher
68. Q. At 200 pounds pressure per square inch,
what is the pressure per square foot on the sheets of
A. About fifteen tons.
69. Q. What is the total pressure on the fire-box
of a large locomotive?[Pg 39]
A. Over 3,000 tons.
70. Q. Give a practical definition of heating
A. The heating surface of a boiler includes all
parts of the boiler and tubes that are directly exposed
to fire or heat from the fire and are surrounded
71. Q. Should an engine be slipped to get water
out of the cylinders or steam passages?
A. No; the water should be worked out by opening
the cylinder cocks and starting the engine slowly.
72. Q. What does it indicate when the smoke
trails back over the train and into the coaches after
A. It indicates poor firing or a lack of understanding
between the engineer and fireman in regard
to where the engine was to be shut off.
73. Q. Before shaking grates or dumping the ash-pan,
what should be observed?
A. That the engine is not passing over bridges or
cattle guards, crossings, switches, interlocking fixtures,
or in yards. Fire on the track should be extinguished
promptly at places where ash-pans are cleaned.
74. Q. Which is easier and more satisfactory on
a long run, to stop and clean the fire if necessary or
to continue to the end of a long, hard trip with a
A. Stop and clean the fire if necessary. It will
save fuel and labor during the remainder of the trip
and may also save an engine failure.[Pg 40]
75. Q. Should you examine the flues to see if
they are stopped up and leaking, and inspect the grate
and grate rigging carefully before leaving the engine
at a terminal?
A. Yes, so they can be reported if necessary.
Clean flues and grates working well make a vast
difference in the success of a fireman, and a great
many engine failures could be avoided by keeping the
flues and grates in proper condition.
76. Q. How should cab lamps, signal lamps, oil
cans and lanterns be cared for?
A. They should be kept clean, free from leaks
and always filled and ready for service before leaving
77. Q. About how many drops in a pint of valve
oil when fed through a lubricator?
A. About 4,500 drops.
78. Q. Assuming that five drops per minute are
fed to each of two valves and one drop per minute
to the air pump, how many hours would be required
to feed one pint of valve oil?
A. About eight hours.
79. Q. Assuming that the engine is running
twenty-miles per hour, how many miles per pint
would be run?
A. About 160 miles per pint.
80. Q. How many drops per minute should ordinarily
A. This will vary with the size of the locomotive
and the work to be performed. On small yard engines[Pg 41]
one drop per minute for each cylinder is usually sufficient
and one drop for the air pump every two or
three minutes. This depends on the condition of the
pump and the service being performed. For large
engines in slow freight service four to five drops per
minute, and for large engines in heavy fast passenger
service from five to seven drops per minute should be
fed. Air pumps in freight service where the brake
pipe is in moderately good condition can usually be
run with one or two drops per minute when handling
long trains of cars equipped with air brakes.
81. Q. Will any bad results ensue from filling the
lubricator full of cold oil?
A. Yes; when the oil gets hot it will expand and
may break the glass or bulge or burst the lubricator.
82. Q. If a sight feed gets stopped up, how could
you clean it out?
A. Close the water valve and the regulating valves
to the other feeds. Open drain cock and draw out a
small quantity of water so as to bring the oil in top
part of lubricator below the top end of oil pipe leading
to feed arm, then open wide the regulating valve to
feed that is stopped up and the pressure from the
equalizing tube will force the obstruction out of the
feed nozzle and up into the body of the lubricator.
Next, close this regulating valve until the feed glass
fills with water, then open water valve and start feeds.
83. Q. How would you clean out chokes?
A. First, shut off boiler pressure and condenser
valve; next, remove feed valve bonnet, then open
main throttle valve, when the steam from steam chest
will blow back through the choke plug, clearing it of
any obstruction.[Pg 42]
84. Q. What is superheated steam?
A. It is the saturated steam separated from the
water from which it is generated with more heat
added, increasing its temperature from 100 degrees
to 250 degrees Fahrenheit above the saturated steam
85. Q. What is the advantage of superheating or
increasing the temperature of the steam?
A. By increasing the temperature of the steam the
volume of a given weight of steam is increased and
all losses due to cylinder condensation are eliminated,
which result in a reduced steam consumption, a saving
in coal and water and increased boiler capacity.
86. Q. How is the increased temperature obtained
by the use of the superheater?
A. By admitting the saturated steam into a partitioned
receiver which has a number of 1½-inch
pipes attached to it. These are located in and extend
nearly the full length of the large flues, the steam
having to pass through these 1½-inch pipes on its
way back to the receiver, absorbs the heat from the
gases passing through the large tubes, causing its
temperature to rise, or in other words, become superheated.
87. Q. How much is the volume of steam increased
A. For each 100 degrees of superheat added to
saturated steam, at temperatures ordinarily used in
locomotive practice, the volume of a given weight is
increased roughly from sixteen to seventeen per cent.
88. Q. Why is the superheated steam so much[Pg 43]
more economical on coal and water than the saturated
A. Because for a given amount of water evaporated
you can increase the volume of steam 33 per
cent. by superheating. It is readily seen that the coal
does not have to be burned if the steam used has 33
per cent. more volume for filling space, or in other
words, only so much steam can be admitted to the
cylinders for every movement of the valve, and what
can not be used must remain in the boiler, so if the
engine can not use all of the steam that the boiler is
capable of generating, the saving must show in coal
and water. If you can not use all of the steam you
do not have to burn coal to make it.
89. Q. Which is the better practice, to close the
feed valves or water valve while waiting on sidings,
A. Close the feed valves; the water valve may
90. Q. How can you tell if equalizer tubes become
stopped up or broken?
A. If they were stopped up the equalization
would be destroyed, and when the steam-chest pressure
was less than the boiler pressure the feed would
work too fast, the oil would enter the feed glass in a
stream instead of forming into drops. If they were
broken, the lubricator could not be used. The auxiliary
oilers would have to be used to lubricate the
1. Q. Explain how an air compressor should be
A. A compressor should be started slowly, with the
drain cocks open to allow the water of condensation
to escape; and as no provision is made in the steam
end to cushion the pistons at the end of their stroke,
it should be allowed to work slowly until a pressure
of thirty or forty pounds has accumulated in the main
reservoir; the piston, having to work against this pressure,
will be cushioned at the end of each stroke.
After the compressor is warm, the drain cocks should
be closed and the throttle opened sufficiently to run
the compressor at the proper speed. The lubricator
should then be started and allowed to feed freely until
eight or ten drops have passed, when the feed should
be reduced to an amount sufficient for proper lubrication.
2. Q. What kind of oil should be used to lubricate
both the steam and air cylinders of the compressor?
A. Valve oil.
3. Q. Where does the main reservoir pressure begin
A. Begins at the discharge valves in the compressor
and ends at the engineer's brake valve.
4. Q. Where does the brake pipe pressure begin
A. The brake pipe pressure begins at the feed
valve and ends at the brake pipe side of the triple
piston, conductor's valve and at the rear angle cock.[Pg 45]
5. Q. What is meant by excess pressure, and
where is this pressure carried?
A. Excess pressure is carried in the main reservoir
and is the pressure above that in the brake pipe.
6. Q. Why is excess pressure necessary?
A. To insure the prompt release of all brakes and
quick recharge of the brake pipe and auxiliary
7. Q. How is the amount of excess pressure
A. By the compressor governor.
8. Q. Name the different parts of the air brake
as applied to a car.
A. The triple valve, auxiliary reservoir, brake
cylinder, brake pipe, angle cocks, cut-out cock, retaining
valve, centrifugal dirt collector and strainer
9. Q. What is the duty of the triple valve?
A. The triple valve has three duties to perform:
Charge the auxiliary reservoir; apply the brake; and
release the brake.
10. Q. What is the purpose of the auxiliary
A. It is here that the air is stored that is admitted
to the brake cylinder when the brake is applied; thus,
each car carries its own brake power.
11. Q. What is the purpose of the brake cylinder?[Pg 46]
A. It is here where the power of the compressed
air is converted into work by forcing the brake piston
out, moving the brake levers, rods and brake beams,
forcing the brake shoes against the wheels, applying
12. Q. What is the purpose of the brake pipe and
A. It is through the brake pipe that all brakes in
the train are placed into communication with the
brake valve on the locomotive; and through the brake
pipe, air from the main reservoir flows to the triple
valves and auxiliary reservoirs on the different cars.
The angle cocks are for the purpose of opening and
closing the ends of the brake pipe.
13. Q. What is the purpose of the cut-out cock?
A. To cut out any brake that is not in operating
14. Q. How is a brake cut out?
A. By closing the cut-out cock in the cross-over
pipe and bleeding the auxiliary reservoir.
15. Q. How would you bleed an auxiliary reservoir?
A. By holding open the release valve on the
reservoir until all air has escaped.
16. Q. How would you bleed off a stuck brake?
A. By holding open the auxiliary release valve
until the brake piston starts to move toward release
1. Q. What are the fireman's duties on arrival at
the enginehouse previous to going out on an oil burning
A. In addition to the duties usually performed on
any engine, the fireman should observe the condition
of draft pans and arch, observe the condition of
burner and dampers; try the oil regulating valve; see
that the burner is properly delivering fuel oil to the
fire; see that the oil heaters are in working order;
that the fuel oil is heated to proper temperature; and
see that proper supplies of fuel oil, sand and water
have been provided as well as the necessary tools for
handling an oil fire.
2. Q. How warm should the oil be at all times
in the tank.
A. Warm enough to flow freely at all times,
usually about 112 degrees. This temperature is about
that which the hand can bear on the outside of the
3. Q. If the oil is too warm, what happens?
A. Many of the good qualities of the oil may be
lost by keeping it too warm, and the burner is more
difficult to operate and does not work as well when
the oil is kept at too high a temperature. Should the
oil be too warm, it will give off too much gas which
would be liable to cause an explosion in the oil tank.
4. Q. What tools are necessary for firing purposes
on an oil burning locomotive?
A. The tools necessary for firing an oil burning
engine include sand horn, brick hook, and a small
iron bar to be used in cleaning carbon from the mouth
of the burner.[Pg 48]
5. Q. What is liable to happen if the heater valve
is open too much?
A. If the heater valve is opened too much it would
be liable to burst the heater hose as well as to heat
the oil to a too high temperature and place an unnecessary
strain on all the heater connections, causing
them to leak.
6. Q. What should be done on approaching stations
where additional supply of fuel oil is to be taken?
A. Shut off the fire, close safety and main oil
valves, remove any lamps that are so close as to be
unsafe when manhole cover is open.
7. Q. What care must be exercised in the use of
lamps, torches or lanterns about oil tanks whether
hot or cold?
A. Never permit oil lamps or oil torches to be
carried within ten feet of the tank opening. Only
incandescent lamps or pocket flash lights should be
used around oil tank manhole when taking oil.
8. Q. How can oil in the tank be measured without
taking a light to the manhole?
A. By inserting a measuring stick into oil in tank
and taking stick to the light for reading.
9. Q. What precautions must be taken before
entering tanks that have been used for oil to clean or
A. Oil tanks, before being entered by workmen,
should be thoroughly steamed and cooled before
being entered. For safety they should be steamed
from six to eight hours.
10. Q. How should the fire be lighted in an oil
burning locomotive?[Pg 49]
A. First see that no one is working under the
engine, that there is the proper amount of water in
the boiler and that it will flow through the gauge
cocks, that there is no accumulation of oil in the ash-pan
or fire-box or existing leaks throughout. If there
is no steam in the boiler, the steam connections can
be made to the three-way cock at the smoke-arch
that will answer for blower and atomizer. If there
are twenty pounds of steam in the boiler, it can be
operated with its own blower. If oil in the tank is
too cold to flow into the burner readily, it must be
heated. Open the front damper and put on the blower
strong enough to create the necessary draft, open the
atomizer valve long enough to blow out any water
that might be in the steam pipe to the burner, then
close the valve and throw a piece of burning waste
in front of the burner and open the atomizer valve
enough to carry oil to the burning waste and open the
regulating valve slowly until the oil is known to be
ignited. Watch the ignition through the hole in the
fire-box door, then regulate the steam and oil supply
to suit. Be sure that no oil is wasting below the burner
or an explosion may result that will prove disastrous.
11. Q. Should the fire go out and it is desired to
rekindle it while bricks are hot, is it safe to depend
on the hot bricks to ignite the oil without the use of
A. No; depending upon the heat from the firebricks
to re-light the fire is dangerous and forbidden.
12. Q. What is termed an atomizer, and what
does it perform?
A. The atomizer is a casting containing two long
ports with an extension lip; the upper port is for oil
and the lower one for steam. The lip aids the steam
in atomizing and spreading the oil, which, when prop[Pg 50]erly
mingled with the air and ignited, will produce
combustion. The atomizer is located just under the
mud-ring and pointed a little upward, so the stream of
oil and spray of steam would strike the opposite wall
a few inches above the bottom if it would pass clear
across the fire-box.
13. Q. In starting or closing the throttle of the
locomotive, how should the fireman regulate the fire,
in advance or after the action of the engineer?
A. In starting an oil burning engine the oil should
gradually be brought up as the throttle is opened and
the movement and amount of oil should be kept
slightly in advance of the action of the engineer in
order to prevent an inrush of cold air as the engine
is working, which would result in injury to the fire-box
and flues. When the throttle is to be closed, the fire
should be reduced very slightly in advance of the
closing of the throttle. This is to prevent the engine
from popping off and black smoke drifting back over
14. Q. Is it necessary that the engineer and fireman
on an oil burning locomotive work in perfect
harmony and advise each other of intended action at
every change of conditions?
A. Yes; they should work in harmony with each
other on any locomotive. The fireman should watch
every move the engineer makes, and the engineer
should advise the fireman of every intended change
of the throttle, so he can operate his valves accordingly
and save fuel and avoid black smoke.
15. Q. What is the effect of forcing the fire on
an oil burning locomotive?
A. Forcing the fire is very hard on fire-box sheets
and flues, and will cause them to leak. An even[Pg 51]
temperature should be maintained in the fire-box of
16. Q. Is a careful regulation of steam and oil
valves and dampers necessary to obtain the most
A. Yes; the fireman's oil valve should be opened
just wide enough to permit a sufficient amount of oil
to be fed to produce a good fire, but not wide enough
to waste oil or produce a volume of black smoke.
17. Q. How can you judge whether the combustion
is good or bad, so the valve may be regulated
A. By the color of the fire in the fire-box. When
it is a dull red color, the temperature is below 1,000
degrees and combustion is incomplete, dense black
smoke will issue from the stack. If it is a bright red,
the temperature will be about 1,800 degrees and combustion
very good, and no black smoke will appear
from the stack.
18. Q. How should the flues be cleaned from soot
when running, and about how often is this necessary?
A. By placing a small quantity of sand in an
elbow shaped funnel or horn, and by inserting same
in an opening provided in fire door while engine is
working hard, allowing the exhaust to draw the sand
through the flues, thus cutting soot and gum from them
in its passage and discharging it from the stack. It
is necessary that the flues be cleaned of soot on leaving
terminals or sidings where the engine has been at
rest for any length of time, and also as often as found
necessary to aid the engine in steaming. This depends
to a great extent upon the degree of perfection with[Pg 52]
which combustion is obtained. Attention should also
be given flues just prior to entering points where
engine is to be put in roundhouse or otherwise detained
in order to leave the flues clean, as this will
aid in putting engine under steam with little delay
where the blower alone is to be relied on for draft.
19. Q. Is the injudicious use of the blower particularly
injurious on an oil burning locomotive?
A. Yes; the injudicious use of a blower is injurious
to any boiler. The cold air drawn through
the fire-box is hard on the sheets and flues and will
cause them to leak.
20. Q. Is the blower more injurious when a light
smoke is emitting from the stack or when a dense
black smoke is emitting?
A. It is most injurious when a light smoke is
21. Q. In drifting down long grades should the
fire be shut off or burned lightly? Why?
A. The fire should be burned lightly and not
permitted to get low enough to allow the fire-box to
lose its temperature, as this will contract the flues and
cause them to leak.
22. Q. How should the fire be handled when
A. The fire must be regulated to meet the requirements
of the work the engine is performing on
each move and to protect against any possibility of
the fire being drawn out by the exhaust.
23. Q. Would not some fuel be wasted in this
A. Not necessarily. A waste of fuel can be
avoided by close attention on the part of the fireman
when switching as well as when running.
24. Q. How should the fire be handled when
A. It should be burning brightly and strong
enough to prevent the draft from putting it out when
the throttle is opened. And a little smoke should
show up at the stack, which would indicate that the
fire was being forced just a little ahead of the working
of the engine.
25. Q. Which is desirable, to use as much or as
little steam jet atomizer as possible?
A. It is desirable to use as little atomizer as will
make engine show perfect combustion and economy.
26. Q. What is the result of too little steam jet
atomizer when standing at stations or when the engine
is working light?
A. The result of too little atomizer when standing
at station or when engine is working lightly, will result
in the oil not being carried far enough into the fire-box
or arch and not properly atomized and the fire is
liable to go out. The oil will drop from the mouth of
the burner into the draft pan to the ground where it is
very liable to start a fire under the engine.
27. Q. If too much steam jet atomizer is used with
a light fire?
A. It will create a disagreeable gas, which will
cause the fire to burn with a succession of light explosions
and kicks, also a waste of steam, and which
would reduce the fire-box temperature.
28. Q. When the fire kicks and smokes, what
should be done?[Pg 54]
A. The atomizer should be adjusted. If this does
not overcome the trouble, the heater should be put in
service, for, possibly, the oil is too cold to flow freely.
Another cause of the fire kicking and smoking results
from water being mixed with the oil. If this is the
case, it should be drained out of the oil tank immediately.
29. Q. How should the dampers be used on an
oil burning locomotive?
A. They should be opened just enough to admit
sufficient air to produce perfect combustion, but not
enough to cool the fire-box. The dampers should be
closed when the engine is drifting or when at rest and
the fire is cut very low or is out entirely.
30. Q. About how much smoke do you consider
an oil burning locomotive should make under adverse
conditions, when the engine is steaming well, but is
being crowded by the engineer?
A. Only a light smoke should show at the stack.
31. Q. What color is most desirable at peep holes
in the fire-box?
A. A white color is most desirable.
32. Q. What will produce the bright red color?
A. Leaky steam pipes, side seams, flues and improper
combustion will produce a ruddy color in the
33. Q. How does water in the oil affect the fire?
A. Water in the oil will produce popping or kicking
with the fire in the fire-box and at times the fire[Pg 55]
will die down entirely and then flash up as the water
disappears and the oil reaches the burner. The most
noticeable result of water in the oil is the fact that
the fire will get very low. It will almost go out entirely
and then will suddenly flash up again as the oil
appears. Water in the oil produces a very dangerous
condition and should be prevented immediately by
draining the water from the fuel oil tank.
34. Q. Do you consider it advisable to keep the
burners clean, and how often?
A. When equipped with steam blow-out pipes,
they should be blown out before commencing trip so
that burners will distribute oil evenly to each side of
35. Q. What position should burner be with
reference to level and in line with center of fire-box?
A. It is very essential that burners be level and
throw flames just to clear floor of arch in order to
derive full benefit of heating surface, as the draft has
a great tendency to elevate flames, at opposite end of
36. Q. Are you aware that in course of time the
atomizer port will become worn too large and will
discharge too large a volume of steam to properly
atomize, and the remedy?
A. Yes; the lip or bushing should be closed to
proper opening so that steam will be restricted at the
nozzle and escape with a bursting effect to properly
atomize the oil instead of flowing out in quantities
against flash walls before it has time to ignite.
37. Q. What is the real object of having the fire-box
lined with bricks, and will engine steam without
A. Not so well as with the brick, the sheets being
in contact with water are too cool to flash the oil
readily and hence the use of what is called a "flash
wall" built of fire brick and heated to a very high
temperature aids combustion very materially.
38. Q. Do you consider it your duty to keep
close inspection of brick work as to need of repairs,
such as air entering between brick and side sheets?
A. Yes. To see that plaster is kept between the
walls and sheets to keep cold air from being drawn in.
39. Q. Will engine steam if brick falls in front of
burners or in path of flame and what may be done?
A. No. Remove them with the brick hook or rod
by pulling them out through damper of draft pan.
40. Q. Where engine is equipped with an oil-reheater
or oil line, do you consider it a help to
engine's steaming qualities when used?
A. Yes; at all times this heater should be used.
41. Q. Why use second heater? Why not heat it
to a high temperature in oil tank with oil heater?
A. Too much gas generating and boiling the oil
continually destroys the higher qualities besides being
hard to control the flow through regulation valve.
42. Q. Do you consider a vent hole in oil tank
advisable, and why?
A. Yes; to allow any accumulation of gas to escape
and to admit the air so that oil will flow freely.
43. Q. Do you inspect your oil pipes and report[Pg 57]
all leaks? What other bad effect has a pipe leak
aside from waste of oil?
A. Yes. It will cause oil to feed irregularly.
44. Q. Are you aware that keeping the flues clean
is the greatest one thing that you can do in regard
to fuel economy, and how often should they be
A. Yes. At least every ten miles.
45. Q. Do you know that the engine should be
working hard and at a speed not less than twenty
miles per hour when sanding flues to avoid the sand
falling to floor of the fire-box and accumulating in
front of them?
46. Q. Do you realize that on first closing throttle
you should not adjust fire too low? Explain best
A. Yes. I would allow steam pressure to fall back
some fifteen pounds before throttle is closed and on
having closed same leave a good fire in box, allowing
it to cool gradually to avoid leaky flues, broken staybolts,
cracked sheets caused by sudden fall of temperature.
47. Q. How is the flow of oil controlled?
A. By the valves in tank and pipe connections.
48. Q. Name these valves, their location and
A. The safety valve controls the flow of oil from
the fuel oil tank through an opening in bottom sheet
of tank to the pipes leading to burner. This valve is[Pg 58]
forced to its seat by a heavy spring and is held off
its seat by a key in the upright rod extending above
the top of tank. To this key a rope or chain is
attached and also attached to the cab to cause the
pin in rod to be pulled in case of a separation between
engine and tank and allow the valve to be seated by
its spring and avoid a waste of oil. The second or
main oil valve is located in oil pipe under deck leading
to burner. It is usually of the plug-cock pattern connected
by bell crank and this connected to some part
of the engine by chain, in which case it also acts as
a safety valve in case of separation between engine
and tender. In other cases it is connected by an operating
rod extending above deck of tender where it can
be operated by hand in case of safety valves failure to
shut off the flow of oil. The third or firing valve is
usually located between heater box and burner, and
is provided with an upright rod extending into cab
where it is provided with a handle or lever in position
to be conveniently handled by fireman while seated in
cab. This valve regulates the flow of oil desired to
reach the fire.
49. Q. When shutting out fire which valve should
be closed first? Why?
A. The safety valve. To allow the oil in pipes
to be consumed and to see that this valve is in working
50. Q. Should safety valve fail to shut off the
flow of oil in such cases would it be safe to rely on
the firing valve to shut off the fire?
A. No. The main valve should then be closed.
51. Q. Should the firing valve be depended upon
to shut off the fire at any time? Why?
A. No. From constant use they are frequently[Pg 59]
leaking and the trouble is not detected while in use,
and again there is always danger of the handle being
moved by workmen or others about the cab.
52. Q. What is a heater box?
A. It is an apparatus having two passages, one
for steam passing from boiler to heater pipes in tank
and another passage for oil from tank before it is
delivered to burner. In this manner the oil before
reaching the burner is heated much higher than the
temperature of that contained in tank.
53. Q. In the event of the heater pipes or connections
becoming defective, how could the oil be
heated in tank?
A. By closing the firing valve, closing the valve
on heater pipe, and opening valve on heater box, the
steam from heater throttle can be passed directly
through the oil feed pipe to the fuel supply.
54. Q. In the event of an objectionable quantity
of water in oil, how can it be removed?
A. In some instances the tanks are provided with
drain pipes for this purpose, but in the absence of
same, the feed hose or pipe between engine and tank
can be disconnected and used as a drain to fuel oil
55. Q. What effect has leaks between fuel tank
and firing valve?
A. A waste of oil only.
56. Q. What effect has leaks between firing valve
A. In addition to a loss of oil while fire is burning
low, and but little steam atomizer being used, it[Pg 60]
interferes very materially with the engine's steaming
by admitting air when using considerable steam
atomizer. This causes a very irregular oil feed.
57. Q. What action of the fire would indicate
leaks in pipes between firing valve and burner?
A. The fire-box will give off sounds similar to
slight explosions, and the smoke at stack will indicate
irregular fuel feeding.
58. Q. What would you consider the proper adjustment
A. That which will provide for the delivery of
the oil from burner to flash wall without striking arch,
side walls, or floor brick while doing so.
59. Q. In case it becomes necessary to fire up an
oil burning engine with wood, what parts should be
given particular attention?
A. The brick work. To see that same is not
damaged or displaced while placing the wood in fire-box,
also to protect by placing brick over that portion
of burner extending into fire-box ahead of mud ring,
or by so arranging the wood in fire-box as to prevent
any great amount of heat from reaching the burner
and melting nozzle of same.
60. Q. In case of sudden drop in steam pressure,
what might be the cause?
A. Loose brick perhaps fallen in front of burner
and obstructed the flow of oil. The petticoat pipe
may be loose and out of line or the dampers may
have fallen shut.
61. Q. In case brick have fallen in front of
burner, how can they be removed?[Pg 61]
A. By a hook provided for that purpose. They
can usually be forced out through the vent openings,
but if this cannot be done, they should be thrown
against the blast wall in order to get them as far as
possible out of the course of the fuel feed.
62. Q. In case a petticoat pipe becomes deranged,
what can be done?
A. In case it cannot be put back in proper position,
it should be removed altogether. (Trips have
been successfully completed in this manner.)
63. Q. Will a corroded burner mouth prevent the
proper delivery of fuel to fire?
64. Q. What causes the mouth of burner to corrode?
A. The asphaltum and sand contained in the oil.
65. Q. How can this be removed on the road?
A. By having a hook or rod provided with a point
that can be inserted into mouth of burner.
66. Q. Why should a fuel oil tank not be filled
to its holding capacity?
A. Because when heater is applied the oil would
expand and overflow.
67. Q. In case of derailment or other accident
that might cause the fireman to desert his position in
cab, what should he do?
A. Pull key out of safety valve rod, thereby
allowing oil feed from tank to be shut off.
1. Q. What are the duties of an engineman before
attaching a locomotive to the train?
A. He should make a complete inspection of the
locomotive, observing all important nuts and bolts,
look for any signs of hot bearings on previous trip,
see that the engine is equipped with necessary tools
and supplies, test both of the injectors and the air
brake equipment to be sure they are in good working
order, see that headlight and signal lamps are in place
and ready for service, observe water conditions in
boiler, inspect the interior of the fire-box and see that
the locomotive is properly lubricated.
2. Q. What tools should there be on the locomotive?
A. Such as are necessary to properly operate the
locomotive, care for the machinery, disconnect and
block up in case of breakdown and the necessary
3. Q. What examination should be made after
any repair work has been done on valve, brasses, etc.?
A. See that brasses are properly fitted, keys
fastened and nuts made tight. If any repairs have
been made on valves or valve gear, would see that
the reverse lever could be moved freely and that all
movable parts had been properly replaced; would
also give especial attention with reference to lubrication
of these parts.[Pg 63]
4. Q. What attention should be given to boiler
attachments, such as gauge cocks, water glasses, etc.?
A. Would see that the gauge cocks can be opened
to try the water and closed, so steam and water would
not come out into cab. Observe the water glass and
note if water is moving up and down in the glass, see
that the steam valve at the top and water valve at
bottom of glass could be opened and closed, and
allow water and steam to circulate freely through the
5. Q. What do you consider necessary to report
on locomotive boilers?
A. Should report all defects on boiler and its attachments
while engine is in engineer's charge.
6. Q. Trace the steam from the boiler through
the cylinders to the atmosphere and explain how it
A. Steam enters the throttle valve located in the
highest part of the dome in order to get the driest
steam, then passes through the standpipe and dry
pipe out of the boiler to the steam pipe tee or nigger-head
located in the front end, then through steam
pipes to the steam chest. A steam valve in each
steam chest distributes the steam so that it enters the
cylinders at or just before the beginning of the stroke;
pushing the piston to the end of its stroke; just before
the piston reaches the end of the cylinder, the steam
valve opens communication to the exhaust port
through a cavity in its exhaust side, then through the
exhaust pipes and tips up through the draft or petticoat
pipe and stack to the atmosphere. When steam
pushes the piston through the cylinder, its power is
transmitted by the main rod to the main crank pin[Pg 64]
which causes the wheels to revolve, thus moving the
engine and its train.
7. Q. Why is it important that there be no holes
through the smoke-box door or front end and none
in smoke-box seams or joints?
A. So as to maintain as good a vacuum as possible
in the smoke-box and prevent small amounts of
air coming in through leaks which tend to heat and
warp the smoke-box and its door.
8. Q. How should the locomotive be started to
avoid jerks, and what train and other signals should
be looked out for at the time of starting?
A. Place the reverse lever in full gear, open the
throttle valve gradually so as to start the train one car
at a time and easily. Look for signals ahead to show
that the track is clear and switch is in correct position,
then look for signals from the rear end that the train
is all coming.
9. Q. Will an engine equipped with superheat
units move as quickly as a saturated steam locomotive
when throttle valve is first opened?
10. Q. Why?
A. Because steam must first pass through superheat
units before it enters the steam pipes leading to
11. Q. In placing engine on the turntable, at
water or stand pipes, or at other similar places, what
must be done?
A. Close throttle valve sooner so that the steam
confined in superheat units, pipes and steam chests,
will have passed out to the atmosphere.[Pg 65]
12. Q. After a
has been started, how
can it be run most economically?
A. By regulating the supply of steam to the steam
chest with the throttle and the point of cut-off with
the reverse lever; so that no more steam be used than
necessary to maintain the proper speed, whenever
possible working the engine at short cut-off so as to
use steam expansively.
13. Q. What is meant by working steam expansively?
A. Hooking the reverse lever up toward the
center gives the valve a shorter travel and closes the
live steam port when the piston has made only a part
of its stroke. This cuts off the supply of live steam
coming from the steam chest. The expansion of the
steam already in the cylinder pushes the piston to the
end of its stroke without the use of a full cylinder of
14. Q. How rapidly should water be supplied to
A. No faster than it is evaporated into steam, unless
just before a hard pull; or when shutting off
with a heavy bright fire in the fire-box to prevent
waste of steam at the pops.
15. Q. What is the difference between priming
and foaming of a locomotive boiler?
A. Priming is caused by carrying the water too
high in the boiler so that when the throttle valve is
opened some of it passes over with the steam in the
form of a spray. Foaming is caused by the water
becoming dirty from animal or alkaline matter, so
that heat makes it foam like soap suds. Muddy water
or certain vegetable matters will also make a boiler
16. Q. What should you do in a case of foaming?
What in a case of priming?
A. In a case of foaming, if possible, allow the
boiler to cool off a little, increase the supply of feed
water to prevent water getting too low, and whenever
possible blow some of the dirty water out of the
boiler, replacing it with clean water. In case of priming,
shut off the supply of feed water until the water
level drops to the proper height in the boiler.
17. Q. What danger is there when the water
foams badly? When it primes badly?
A. There is danger of knocking out cylinder
heads, cutting the valves, stalling on some grade or
getting on some train's time because the engine cannot
be worked to its proper power. When shutting
off steam, the water is liable to drop below the crown
sheet and thus risk burning the fire-box. When water
primes badly, it is liable to break cylinder packing
rings, knock out cylinder heads, break bolts in the
steam chest and cut the valves. In such a case additional
oil should be fed to the steam chest until the
valves are properly lubricated.
18. Q. Suppose that with the water glass in good
working order, immediately after closing the throttle
the water disappeared from the water glass, what
should be done?
A. Would open the throttle and endeavor to raise
water until both injectors would put enough water
into the boiler to make it entirely safe to close the
throttle. If unable to raise the water level to the
lower gauge cock would smother the fire or put it out
entirely, if necessary, keeping both injectors working.[Pg 67]
19. Q. What work about a locomotive should be
done by the engineman?
A. Inspection of the engine both before and after
the trip. The engineer should do any necessary work
on the engine after starting out on the trip to avoid
breakdowns and insure getting over the road promptly.
This means tightening up any important bolts that
work loose on the trip and keeping parts from working
out of position, adjusting wedges and rod keys.
20. Q. How should the work of setting up the
wedges be done?
A. Place the engine on the upper quarter on the
side with the loose wedge. Do not set the brake if
brake shoe will push the driving box against the defective
wedge, but block engine truck wheels so the
engine cannot move, push the boxes against the shoe
or dead wedge with a little steam, set the wedge up
until it is a snug fit, then pull it down about one-sixteenth
of an inch and fasten. Provision should be
made for expansion of the box when it gets warm.
21. Q. How should rod brasses be keyed?
A. If properly fitted they should be keyed brass
to brass; if not so fitted, they should be keyed on
the large part of the pin so they will be free enough to
run without heating and snug enough to run without
pounding. Do not key them so tight at either end as
to prevent the lateral motion of the brass on the pins.
22. Q. How should an engine be placed for the
purpose of keying the rod brasses?
A. For the main rod, place the engine on the
quarter or the top forward eighth, whichever place
gives the largest diameter of the pin to key the brass[Pg 68]
against. After keying up, test by moving the wheel
to another position and see if brasses are free on the
pin. For the side or parallel rods, always place the
engine on the center for the side that is to be keyed.
23. Q. How should the side rods on a mogul or
consolidation locomotive be keyed?
A. Place the engine on the center on that side,
key up the brass on the main pin first, work each
way toward the ends of the rods, being careful to
keep them the proper length so they do not bind
when passing either center. Be sure that wedges are
properly set up before keying the side rods.
24. Q. What is the necessity for keeping the
brasses keyed up properly?
A. If too tight, they will surely run hot; if too
loose, they will pound and injure the brasses as well
as endanger the safety of the straps and rod bolts.
Very loose brasses can pound enough to get hot.
25. Q. What is meant by an engine out of tram?
Out of quarter?
A. When corresponding wheels on opposite sides
of the engine on different axes are not spaced equally
apart; where the axle of any wheel is not at a right
angle to the center line from front to rear of engine,
so they do not run square on the rails, or where the
space between the axle centers on opposite sides is
not equal. This is sometimes indicated by unequal
flange wear and should be reported at once. Wheels
are out of quarter when the crank pin in one wheel
is not exactly 90 degrees or one quarter of a turn
from the pin in the wheels on the other end of the
same axle. This is usually caused by slipping the
engine with sand on one rail only and the condition
of engine should be reported at once.[Pg 69]
26. Q. Describe a piston valve.
A. A piston valve is a cylindrical spool-shaped
valve constructed with packing rings much the same
as the steam piston that moves through the cylinder,
except that a piston valve is double or composed of
two pistons connected by center rod or spool working
in a bushing of equal diameter. Steam and exhaust
ports are cut through this bushing; steam ports to the
cylinder and exhaust port to the exhaust pipe. There
is also a steam port for live steam from the boiler.
As the pressure on this valve is equal in both directions
it is practically balanced.
27. Q. What is a balanced slide valve? How is
it balanced, and why? For what purpose is the hole
drilled through the top of the valve?
A. One in which the steam pressure on the top
and bottom of the valve is nearly equalized. This
is done by protecting a portion of the top of the
valve from the steam pressure. It is usually balanced
by strips held against the pressure or balance plate
by one or more springs. This is done to prevent live
steam from getting on top of valve and thus relieve
the valve from the top pressure which would cause
excessive friction between the bottom of the valve
and its seat. The hole through the top is to allow
any steam which might leak by the strips to pass
into the exhaust, so pressure could not accumulate
on the top of the valve, also to equalize the exhaust
pressure between the top of the valve and exhaust
cavity as well as to assist in lubricating the balance
28. Q. What is meant by inside and outside admission
A. With an inside admission valve (usually a
piston valve), the live steam comes between the piston
valve heads, the outside end of the heads being connected
with and exposed to exhaust pressure, it admits
steam past the inside edges of the valves. An outside
admission valve has the space between the ends connected
to the exhaust and a space at the ends connected
with the live steam. It admits steam past its
outside edges. A piston valve can be either inside or
outside admission, while a slide valve is always outside
29. Q. What is the relative motion of the main
piston and the steam valves for inside admission, and,
on the other hand, for outside admission?
A. If the piston is in the front end of the cylinder,
an inside admission valve must move forward in order
to connect the inside of the valve with the front live
steam port to admit steam against the piston. The
outside end of the valve opens the exhaust port for
the back end of the cylinder. In the same position of
the piston an outside admission valve must move
backwards to open the steam port or in the same
direction as the steam piston when commencing its
30. Q. What is an Allen ported valve, and what
is its object?
A. An Allen ported valve is an outside admission
slide valve having an extra port from one end of the
valve to the other, above the exhaust cavity and
through the body of the valve. This extra port is
calculated to admit steam through the valve at the
same time that steam passes by the end of the valve
into the same steam port, thus doubling the area of
opening for live steam when the port is first opened.[Pg 71]
31. Q. What is the difference in the valve motion
for outside admission valves and for inside admission
A. An outside admission valve must be moved in
the opposite direction to an inside admission valve
in relation to the movement of the steam piston when
beginning its stroke; therefore either the position of
the eccentric or the position of the rocker arms in
relation to the rocker shaft must be opposite for a
change in these valves.
32. Q. What is a direct motion valve gear?
What is an indirect motion valve gear?
A. A direct motion valve gear is one in which the
valve moves in the same direction as the eccentric
rod, that is doing the work, in many cases no rocker
arm is used. In case a rocker arm is used, both arms
point in the same direction like the letter U. An
indirect motion valve gear is one in which the valve
moves in an opposite direction to the eccentric rod
doing the work. A rocker is used in which the arms
point in opposite directions from the shaft connecting
them. Owing to the design and construction of the
Walschaert valve gear, it is a direct motion gear when
the engine is running in one direction with the link
block in the bottom of the link, an indirect motion
when the engine is running in an opposite direction
with the link block in the top of the link; usually
direct motion when running forward.
33. Q. How can you detect the difference between
a blow in valve or piston packing?
A. A blow from the valve is more constant and
has a somewhat different sound, while a blow from
cylinder or piston packing will blow stronger at the[Pg 72]
beginning of the stroke and gradually decrease as
the stroke is completed.
34. Q. How would you place engine to locate
broken admission steam ring in piston valve?
A. Would place engine on quarter, reverse lever
in center so as to cover ports, then open throttle; and
the steam will blow out of cylinder cock at the end
of cylinder where broken valve ring is located.
35. Q. How would you locate broken exhaust ring
in piston valve?
A. Watch the cross-head when engine is working
steam. As there will be three normal and one light
exhausts, you can determine on which side of the
engine the light exhaust takes place.
36. Q. What is meant by lead? What by line
A. Lead is the amount of port opening for live
steam to cylinder ahead or back of piston when the
piston is on the dead center. If the steam edge of
the valve is in line with the edge of the steam port
when the piston is on the center, it is said to be line
37. Q. What is meant by steam lap?
A. The distance that the valve overlaps the live
steam edges of the steam ports when it is in the center
of its travel over the seat. This distance is measured
at one end only, although the valve laps equally at
38. Q. What is meant by exhaust lap? What by
A. Exhaust lap is the distance that the exhaust
edge of the valve overlaps the exhaust edge of the[Pg 73]
steam port when the valve is in central position. Exhaust
clearance is the opening between the exhaust
edge of the valve and the exhaust edge of the steam
port with valve in central position. If the valve has
neither exhaust lap or clearance it is said to be line
39. Q. What is meant by release? What by compression?
A. Release is the point in the travel of the piston
when the port is opened. Compression is the distance
the piston travels after exhaust port closes before the
live steam port opens. During this travel of the
piston the exhaust port is closed so the moving piston
compresses the steam left in the cylinder.
40. Q. With an indirect valve motion and outside
admission valve, what would be the position of the
eccentric relative to the crank pin on that side? What
with a direct valve gear? What difference between
outside admission valve and inside admission valve
as to this position?
A. With an indirect valve motion and an outside
admission valve, the go-ahead eccentric follows the
crank pin with engine running ahead. Without any
lap or lead it would be a quarter of a turn or 90
degrees behind the pin, but as all valves have lap and
lead, the eccentric is advanced or placed toward the
pin enough to move the valve the amount of the lap
and lead. With a direct valve gear and an outside
admission valve, the eccentric will be a quarter of a
turn or 90 degrees ahead of the crank pin and advanced
enough to move the valve the amount of the
lap and lead. With an inside admission valve and an
indirect valve motion, the eccentric will come the[Pg 74]
same as for an outside admission valve and direct
motion, or more than a quarter of a turn ahead of the
pin. With an inside admission valve and direct motion,
as piston valves are usually put up, the eccentric
will follow the pin less than a quarter of a turn.
41. Q. What effect would be produced upon the
lap and lead by changing the length of the eccentric
A. Lap depends on the construction of the valve.
A change of the eccentric rod would not effect it, but
would widen the port opening at one end of the travel
and reduce it at the other. It should be equal at both
ends. Lead is controlled by the position of the eccentric
on the axle and it must be equal at both ends.
Changing the length of the eccentric rod from the
proper one does not really affect the lead, because
no proper measurement can be made until lead is
equal at both ends. Therefore improper length of
eccentric rods varies the port opening at the beginning
of the stroke of the piston at both ends.
42. Q. Why are eccentric rods made adjustable?
A. In order to change their length to make adjustment
of the valve gear not as easily made in other
43. Q. Why is it necessary to keep the cylinders
free from water?
A. In order to avoid damaging valves and cylinders,
to insure perfect lubrication and obtain the most
efficient service from the locomotive.
44. Q. Where is the piston rod packing located?
Where cylinder packing?[Pg 75]
A. Piston rod packing is usually soft metallic rings
located inside of a gland at the back end of cylinder
and around the rod. Cylinder packing rings are
usually cast iron, placed around the piston head and
bearing against the walls of the cylinder.
45. Q. How are metallic packing rings on piston
rods and valve stems held in place? What provisions
are made for the uneven movements of the rod?
A. The packing rings fit into a vibrating cup or
cone located inside the gland, being held therein by
means of a spring as well as by the steam pressure.
Provision is made for uneven movement of the rod
by making the inside of the gland larger than the
vibrating cup and using a ball-joint ring between the
vibrating cup and gland.
46. Q. While running under steam and there is a
failure of part of the locomotive which does not seem
to prevent running at full speed, how would you
A. Keep the locomotive running if in your judgment
it is safe. Try to ascertain what the injury is
and be prepared at the next stop to do such work as
the case demands, being careful to make the stop at
such a place that the work can be done without interfering
with the movements of main line trains.
47. Q. If one side of a locomotive is disabled,
what would you do in a general way to make it possible
to use steam on the other side?
A. Disconnect enough parts to allow for the turning
of the wheels and for reversing of the opposite
side without moving the valve on the disabled side.
48. Q. In case a locomotive in your care became
disabled on the road, what would you do?[Pg 76]
A. First see that the train is protected. Next
examine the locomotive and see what is necessary to
do to move it and if possible the train. If unable to
make repairs at once to bring the engine and train
forward, would advise exact condition of engine and
ask for help. In the meantime endeavor to move the
train so as to give other trains the use of the main line.
49. Q. Suppose a wash-out plug blew out or a
blow-off cock broke off or would not close, what
should be done?
A. Kill the fire, get the train on a side track, if
possible, and if unable to make repairs get the engine
in condition to be towed in. In all cases with a disabled
engine allow the train to drift to a siding, when
possible, and stop between the switches so as to allow
other trains to pass through siding.
50. Q. Can a locomotive boiler without steam
pressure be filled by being towed by another engine?
If towed, how filled?
A. Yes. Close all openings where air could enter
the boiler. All relief valves, cylinder cocks, gauge
cocks, the whistle valve and air pump steam valve
should be closed. Place the reverse lever in full gear
in the direction the engine is to be towed with water
supply valve and injector throttle open. Use engine
oil through auxiliary oil cups to oil valves and pistons.
The movement of the pistons in the cylinders will
pump the air out of the boiler and atmospheric pressure
on water in the tank will force water into boiler
when the engine is towed.
51. Q. What should be done if grates should be
burned out or broken while on the road?
A. Pull the fire off the broken or burned grates,
cover that section with any pieces of iron at hand[Pg 77]
(fish-plates or angle-bars are very good), then level
up the fire, clean ash-pan and proceed with full train.
52. Q. What precaution should be taken to prevent
locomotive throwing fire?
A. The netting and smoke-arch should be kept in
good condition; cinder slide and hand hole plates
securely fastened, ash-pan clean and slide dampers
for dumping ashes closed. Care should be exercised
in working the engine, especially in the vicinity of
stations or places where fire is liable to catch. Avoid
working the engine hard so as to prevent throwing
53. Q. What shall be done with a badly leaking
or bursted flue?
A. Plug it if possible with an iron or wooden plug.
If in the fire-box end, a piece of scantling or post can
be sharpened and driven into the flue from the fire-box
door; it will then burn off up to where the water
from the bursted flue keeps it wet. If a bottom flue,
would cover it with ashes or green coal so that the
leakage would not put out the balance of the fire. If
able to maintain steam pressure, would then proceed
with a full train.
54. Q. What should be done in case the throttle
valve stem became disconnected while the valve is
closed? If it became disconnected leaving valve open?
A. Would notify the train crew and Dispatcher
and arrange to be towed in. With lubricator working,
unless in very cold weather so there is danger of the
water freezing in the cylinders or steam chest passages,
would not disconnect. By taking out lubricator
chokes and steam chest valves from the oil pipe, a[Pg 78]
larger supply of steam could be got into the cylinders.
If in to clear of other trains and practicable, would
take up the dome cap and connect the throttle again.
If disconnected and valve stuck open, would notify
the train crew and Dispatcher, reduce steam pressure
until the engine could be handled with
lever and brake, and proceed with such a train as the engine
55. Q. In case a valve yoke or stem became
broken inside of steam chest, how can the breakage
A. In this case the disabled valve is always pushed
to the front end of the steam chest so that with a slide
valve or outside admission piston valve the back port
is open to live steam. When given steam, the engine
will stop on the eighth, and when reversed will move
over to the other eighth, being stopped there by the
live steam in the back end of the cylinder having the
disabled valve. Steam will blow from the back
cylinder cock on the disabled side and cannot be
changed by reversing the engine. If the valve is
pushed far enough ahead to open the exhaust port,
steam will blow through the exhaust so the engine
cannot be moved. With an inside admission valve
the forward steam port will be opened and steam will
come out of the forward cylinder cock on the disabled
56. Q. After locating a breakage of this kind,
how would you proceed to put the engine in safe
A. Would move the valve to central position so
as to cover both steam ports, if possible. This may be
done by taking out the relief valve if on front side of[Pg 79]
the steam chest and pushing valve back, or taking up
the cover for a slide valve; or taking off front head
for a piston valve. Disconnect the valve rod from
rocker arm and block valve stem so it cannot blow
out of the gland or let valve work back. Loosen
cylinder head in order to provide for lubricating cylinder
so as to leave the main rod up on the disabled
side and proceed on one side. If unable to cover the
open steam port it would be necessary to disconnect
the main rod on the disabled side, blocking the piston
at the proper end of the guides so live steam coming
into the cylinder would not move it.
57. Q. If a slide valve is broken, what can be
done to run the engine on one side?
A. Remove the steam chest cover, place a thin
board between the valve and the steam passages in
the seat, replace steam chest cover, disconnect valve
rod, and if able to lubricate the cylinders leave up the
main rod and proceed on one side.
58. Q. If one of the bolts connecting the two
parts of a built-up link on Stephenson gear breaks or
is lost, how would you proceed?
A. If temporary bolt cannot be supplied, take
down the forward part of the link, disconnect and
remove link block, fasten valve to cover ports, and
proceed. If moving link will clear rocker arm or other
parts of the machinery after link block is taken out,
it will not be necessary to disconnect eccentrics.
59. Q. What should be done in case of link saddle
A. Remove the broken parts and block the disabled
link in such a position that the entire train
could be started, using a very short block above the
link block in the link slot and a longer one below it.[Pg 80]
60. Q. With one link blocked up, what should be
A. Reversing the engine or moving the tumbling
shaft arm down so the link on the disabled side can
61. Q. How can it be known if an eccentric has
slipped on the axle?
A. By the uneven exhaust of the engine and a
thorough inspection to determine the cause.
62. Q. Having determined which eccentric has
slipped, how should it be reset?
A. Place the engine on the center on disabled
side and if a back-up eccentric has slipped, would
place the reverse lever in full forward gear and mark
the valve stem flush with the gland; then place the
reverse lever in full back gear and move the slipped
eccentric until the mark on the stem returns to its
original position, taking notice that the throw of the
eccentric is on the other side of the axle from the
go-ahead eccentric used as a marker, and tighten up
set-screws. To set a go-ahead eccentric, use the back-up
one on that side for the marker. If the eccentric
had been keyed on, would move the cam until the key-way
in the axle came in line with the slot in the cam.
Knowing the position of the eccentric in relation to
the crank pin, an inspection would show where it
belongs. The eccentrics are usually opposite the third
spoke in the driving wheel from the pin, sometimes
ahead of the pin, in other cases back of the pin, depending
on whether it is an inside or outside admission
valve, a go-ahead or back-up eccentric.
63. Q. What should be done in case of a broken
eccentric strap or rod?[Pg 81]
A. For a go-ahead strap or rod take down all
broken parts, disconnect valve rod, cover ports, and
come in on one side. It is safer to take down also
the back-up strap and rod on that side. If the back-up
strap and rod is broken, it is possible to secure
the bottom end of the link so it will not turn over,
work the engine full stroke ahead, proceeding with
full train until the main line is clear.
64. Q. How should the engine be disconnected if
the lower rocker arm became broken? If link block
A. Would remove broken parts; if moving link
would strike anything connected with the rocker box
or broken arm it would be necessary to take down
both eccentric straps and rods. Block valve central
over ports and come ahead on one side. If a link
block pin was broken, it might be possible to put a
bolt in there to do the work, otherwise block the valve
on the center of its seat and if the link will not clear
the lower end of the rocker arm take down the eccentric
straps and rod. In any case where necessary to
take off the eccentric rod always take off the strap
65. Q. For what breakdown is it necessary to
take down the main rod? The side rod?
A. A broken main crank pin, broken main rod or
strap, broken piston rod when near the middle of the
rod, broken cross-head or guide, broken valve or seat
when steam cannot be kept out of the cylinder. Side
rods must come down for broken side rod, broken
main pin, or broken side rod pin affecting that rod.
66. Q. If it is not necessary to take down the main
rod of disabled side of the engine, how would you
arrange to lubricate the cylinders?[Pg 82]
A. If cylinder and piston are in good shape and
it is possible to block the valve to admit a small
quantity of steam into the back end of the cylinder,
oil from the lubricator will go through this opening
and oil the piston rod and cylinder packing. If not
possible to block the valve properly, cover the ports
and oil the cylinder through the indicator plug openings
or relief plug holes. If not possible to do this,
slack off the bolts on the front cylinder head, wedge
the head open so oil can be introduced. In some
cases it may be necessary to take the head off; that
however, allows dust and grit to enter the cylinder.
67. Q. What is the by-pass valve, and what is
A. By-pass valves are connected to the steam port
leading to the cylinder. Its duty is to open when
the engine is drifting with steam shut off, and close
when working steam, to allow air to pass back and
forth from opposite sides of the moving piston.
68. Q. What is a vacuum relief valve? What a
cylinder relief valve?
A. A vacuum relief valve is usually located on
the steam chest or the live steam passage to the chest
and opens when steam is shut off and engine drifting,
allowing atmospheric pressure to pass into the steam
chest, closing when working steam. A cylinder relief
valve is a pop valve screwed into the cylinder head
and set at high enough pressure so it does not open in
ordinary service, but will open to allow water to pass
out when the exhaust port is closed by valves; or on
compound engines when the pressure in the low-pressure
cylinder gets too high.
69. Q. What would be considered a bad engine
or tender truck wheel?[Pg 83]
A. One loose on axle; having bad flat spots; very
sharp flanges; bad sand spots; cracks shelled out; or
other defect that would make the wheel unsafe.
70. Q. What should be done if a tender truck
wheel or axle should break?
A. Would place a piece of timber or rail across
the tender, jack up the corner of the truck that is disabled
chain it to the timber and fasten the timber at
the other end to hold it so it would carry the disabled
truck. If it is possible to slide the wheel or truck,
place a tie across the rail and keep the wheel from
turning, then slide it to a siding.
71. Q. What should be done if an engine truck
wheel or axle should break?
A. Would block between the engine frame and
truck frame over the good wheel on disabled side,
swing the disabled corner of the truck to the engine
frame with a chain. Look out when crossing frogs
that disabled truck does not leave the track. With
a broken flange, would block the wheel to prevent
its turning and skid it to a siding.
72. Q. What should be done for a broken tender
A. Jack the tender up to where it belongs and put
a block in place of the broken spring.
73. Q. What should be done with a broken engine
truck spring or equalizer?
A. For a broken spring, raise the front end of the
engine and place blocks across the equalizers under
the truck spring near the spring band. For a broken
equalizer, block on top of engine truck boxes and
under truck frame.[Pg 84]
74. Q. What should be done if a driving spring
hanger or equalizer should break?
A. Would block between the driving box affected
and under the frame over it, using hardwood block
or piece of iron. Would also block the equalizer up
to its proper position between the disabled end and
the frame, or over the other end, as the type of spring
rigging requires, to hold the equalizer level. For a
broken equalizer, would block on top of all boxes
affected, would raise the engine by running the proper
driving wheels upon an incline or wedge to lift the
engine while other boxes were blocked; a re-railing
frog comes handy for this work.
75. Q. How can an engine be moved if the reverse
lever or reach rod were caught at short cut-off
by a broken spring or hanger?
A. By removing the pin at the forward end of
reach rod, to free the tumbling shaft and allow it to
be moved either forward or back to move the engine.
A block should be placed over the link block to avoid
damaging it when uncoupled, as well as to hold link
in proper position to move the engine. This would
allow the engine to be moved and clear the main line.
76. Q. How can the blowing of steam past cylinder
packing, a valve or valve strip be distinguished
A. Test for a leaky slide valve, place the engine
on the quarter on the suspected side with the reverse
lever in center notch; the valve should be in the
middle of its travel and cover both ports. If steam
blows through the open cylinder cocks on that side,
the valve or seat are defective. A leaky balanced
valve strip will allow steam to blow through the hole
on top of the valve into the exhaust port in the seat[Pg 85]
and very little steam will come out of the cylinder
cock; in some cases with the valve barely opening a
steam port to the exhaust, air will draw in at the
cylinder cock. If there is a drip cock in the exhaust
pipe under the saddle, the steam will blow out there.
After testing for leaky valve, place the engine on
about the forward bottom or top back eighth, block
the wheels or set the brakes solid, put reverse lever in
corner, open cylinder cocks and give the engine steam.
If steam comes out of both cylinder cocks, and testing
valve shows it is tight, then the packing is blowing.
Cylinder packing should be tested with steam first on
one side of the piston and then on the other.
77. Q. If engine should blow badly and be unable
to start the train when on the right dead center, on
which side would be the blow generally?
A. On the left side. If the side standing on the
quarter cannot start the train, the trouble is usually
78. Q. If throttle were closed and steam came
out of cylinder cocks, what might be the cause?
A. To test for this, first shut off steam connection
to the lubricator; steam leaking into the cylinders can
come from a leaky throttle or leaky dry pipe.
79. Q. Is it possible to distinguish between a leaky
throttle and a leaky dry pipe?
A. Yes; a leaky throttle usually leaks steam at
all times. A leaky dry pipe will leak both steam and
water. It will show a stream of water at the cylinder
cocks when the water level in the boiler is raised
above the leak in the dry pipe.
80. Q. What effect have leaky steam pipes in the
smoke-arch, and how should they be tested?[Pg 86]
A. Leaky steam pipes waste steam and very
affect the draft in the front end. A bad leak
in the back part of the joint at the bottom will blow
into the tubes and make the engine smoke at the door
with throttle wide open while standing still. To test
them, open the front door and cover the joint with
fine cinders. When the engine is given steam, the cinders
will blow away from the leak; to properly test
them in the shop, water under heavy pressure should
81. Q. How should the test for a leaky exhaust
pipe joint, or a leaky nozzle joint be made?
A. About the only test that can be made on the
road is to open the front end and reverse the engine
with throttle partly opened, watching the suspected
joint at the same time. For the bottom one with
cinders around the joint, for the top one it can sometimes
be detected by holding a torch near the joint.
82. Q. What should be done if a steam chest
A. Would loosen up the steam chest cover to free
the sides, and wedge between the studs and walls of
chest, crowding the broken parts together. A brake
shoe key does this nicely. Would then tighten down
on steam chest cover and proceed.
83. Q. What should be done if a steam chest
A. Would take off steam chest cover, place strips
of boards over the steam inlets and block on top of
them so that the steam chest cover would hold them
in place and prevent live steam coming out of inlet.
Would then make the necessary disconnection and
proceed on one side.[Pg 87]
84. Q. If a link lifter or arm were broken, what
should be done?
A. Take off the disabled parts, block between the
top of the link and link block, having the disabled
link blocked down very nearly in full strokes. For
safety, both the top and bottom of the disabled link
should have blocks in its slot; the good link would be
held in place by the reverse lever and should under
no consideration be dropped down any farther than
the disabled link was.
85. Q. If the reverse lever or reach rod should
break, what should be done?
A. If either breaks, place an iron bar or suitable
piece of material across the top of both frames, securely
fastening it in position, then fasten the arm of
the tumbling shaft to the bar. This will require the
engine to be worked at about half cut-off; handle such
part of the train as the road conditions would permit.
86. Q. What should be done if the piston, piston
rod, cross-head, main rod or crank pin are broken
A. If a piston should break, would remove broken
parts, disconnect valve stem, clamp valve in central
position, and if moving piston would not damage
cylinder, leave main rod up and proceed. If a piston
rod, cross-head, main rod or crank pin are broken or
bent, would take down the main rod, block the valve
and cross-head; if piston rod is broken off at the cross-head,
leave main rod up.
87. Q. What should be done when there is a loose
or lost cylinder key?
A. If the cylinder key is loose, it should be tightened
up; if lost, something should be substituted. In[Pg 88]
case nothing solid can be found to take the place of
the key, the engine should be run in light to avoid
88. Q. What should be done if a safety valve
spring or stud breaks?
A. The steam pressure should be reduced. With
broken spring, screw the parts down solid or clamp
the stem down. This can be done by laying a piece
of scantling across the top of the valve, fastening each
end to the hand rail on opposite sides of the engine in
case of broken stud. Would then raise steam pressure
and proceed. Care should be taken to see that the
other safety valves relieve the steam pressure properly.
89. Q. How can an engine be brought in with a
broken front end or stack?
A. By boarding up the front end to make it as
near air tight as possible and using a barrel or a
petticoat pipe in place of the stack, wiring it fast to
the smoke-arch. Where a portion of the stack is
inside the smoke-box the engine might steam without
the barrel or petticoat pipe.
90. Q. What should be done if the frame is
broken between the main driver and cylinder?
A. Either give up the train and come in light, or
disconnect the engine on that side and come in with
reduced tonnage, depending on how badly the engine
pounds when working steam.
91. Q. If the frame is broken back of the main
A. Do not disconnect and do not try to pull a
heavy train; it is safer to come in with light tonnage.
92. Q. In case of broken side rods, what should
be done?[Pg 89]
A. Take down the broken rod and corresponding
rod on the other side of the engine.
93. Q. What can be done if the intermediate side
rods were broken on a consolidation engine having
the eccentric on the axle ahead of the main wheel?
A. In this case the engine must be towed in. It
is possible when the main pin is broken, so that all
rods on one side are taken off, to leave the rods up on
the other side and move the engine with her own
steam, but very few roads will allow this, because
engineers will be inclined to leave the main rod up
on the disabled side to prevent engine catching on
the center. If main rod is left up on the disabled
side, the wheels will surely slip and wreck the rods
on the other side.
94. Q. Should one of the forward tire, main tire,
intermediate tire, back tire, or a trailer tire break,
what must be done to bring the engine up?
A. Would run the wheel of the broken tire on a
block in order to raise the wheel clear of the rail and
the box up in the driving box jaws. Remove the oil
cellar and place a block between the driving journal
and pedestal brace to carry the disabled wheel center
clear of the rail. Would also block up on top of the
box of the wheel ahead or back as the case might be,
in order to take the weight from the disabled wheel.
It might not be necessary to take off any of the rods,
but would run the engine light to the shop, giving
special attention to lubrication of the disabled wheel
and using extra precaution in entering side tracks and
passing over frogs and switches. With the tire of a
back driver or trailer wheel broken, it is usually necessary
to swing the rear end of the engine from the
tender to keep the rear end on the track. With an[Pg 90]
inside radial journal, box on the trailer axle; for a
broken trailer tire, both trailer wheels must be blocked
and swung clear of the rail.
95. Q. What is a good method of raising a wheel
when jacks are not available?
A. By raising the wheel on a hardwood block or
iron wedge; a re-railing frog comes very handy for
96. Q. How can it be known when the wedges
are set up too tight and the driving box sticks, and in
what manner can they be pulled down?
A. If wedges are set up too tight, it causes the
boxes to stick and the engine to ride rough. Inspection
of the engine when moving will locate the disabled
box; usually this gets hot at once and the
wedges should be immediately pulled down. Loosen
the jam nuts on the wedge bolts and back them down;
if the wedge is stuck very tight it may be necessary
to run one or more of the wheels over a block; or to
loosen the pedestal, brace bolt and allow the jaws to
spread to release the box.
97. Q. What are some of the various causes for
A. Wedges not properly adjusted, loose or worn
driving box brasses, rod brasses not keyed or in need
of reducing, loose side rod bushings or side rod connections,
worn cross-heads, wrist pins, broken frame,
loose cylinder key, loose piston on rod, or rod loose
in cross-head, loose follower bolts or obstruction in
98. Q. How may a pound in driving boxes,
wedges or rod brasses be located, and after locating
what should be done?[Pg 91]
A. Place the engine at half stroke on side to be
tested. Do not set brake when testing for loose
wedges or defective boxes; set brake when testing
for other pounds. Reverse engine from forward to
back gear under steam, noting the movement of the
axle in the boxes, the driving boxes between the
wedges, rod brasses on the pins and movement of
cross-head between the guides. If possible would adjust
wedges or rod brasses at once and report repairs
needed at the terminal.
99. Q. How locate loose follower bolts?
A. Shut off steam and allow engine to drift; there
will be a pound in the cylinder when the loose follower
bolt strikes a forward cylinder-head as the engine
passes the forward center on that side; give engine
steam while still moving and if the pound stops it is
likely to be a loose or broken follower bolt. When
working steam, the compression or pre-admission takes
up the lost motion in the rod and connections, so the
loose bolt does not strike the head; when shut off the
piston travels the extra amount of this lost motion
and the bolt strikes the head.
100. Q. When should cross-heads or guides be reported
to be lined?
A. When there is excessive lost motion between
the cross-head and the top and bottom guides, or
between the cross-head and the guide at the sides, or
when the piston rod is not central between the guides.
101. Q. When should driving box wedges be reported
to be lined?
A. When they have been set up as far as possible
and the boxes are still loose between the wedge and
shoe. At this time would also report any excessive
flange wear on any one particular tire.[Pg 92]
102. Q. When should rod brasses be reported to
be reduced? When to be lined?
A. Rod brasses should be reported reduced when
they are larger than the pins and are pounding and
cannot be keyed up properly. They should be reported
to be lined when the key has been drawn or driven
to its full length and the brasses do not close together
or are too loose in the strap lengthwise of the rod.
103. Q. When should lost motion between engine
and tender be taken up?
A. When the lost motion becomes so great as to
endanger the breaking of connections.
104. Q. How do you proceed to pack a driving
box equipped with a grease cellar?
A. Remove the filling plate on the inside of the
cellar. Pull down the indicators and follower plates,
insert the grease between the follower plate and perforated
plate; when full, replace the filling plate on
the inside of the cellar and allow the spring and follower
plate to force the grease through the perforated
plate to the journal.
105. Q. Please explain the principle on which an
A. With a lifting injector the steam valve is
opened a small amount to furnish steam for the priming
or starting jet. This forces the air in the body of
the injector and top end of suction pipe out through
the overflow valve, producing a partial vacuum in the
body of the injector. Atmospheric pressure in the
tank then forces the water into the injector body.
When it begins to come out through the overflow, a
further movement of the steam valve opens the forcing
valve wide, so a full supply of steam strikes the water[Pg 93]
at a high velocity and at the same time condensing.
This action of the steam gives the water sufficient
velocity to overcome the boiler pressure and pass into
106. Q. Explain the passage of steam from the
boiler to the steam heat pipe.
A. Steam is admitted to the steam heat pipe, in
which there is placed a reducing valve through which
it passes at reduced pressure, into the steam heat pipe
under the entire length of the train. The reducing
valve is located in the cab close to the steam heat
107. Q. If the steam heat gauge shows proper
pressure, but the steam heat pipe pressure appears to
be low, what should be done?
A. If the steam heat gauge is showing the correct
pressure, there is an obstruction in the pipe somewhere,
most likely in the steam heat hose, and this
should be looked for and remedied; if the gauge is
correct, then it is the reducing valve that is at fault
and this should be readjusted, as well as the gauge.
108. Q. What is the cause of failure with the
second injector, and what should be done to obviate
A. Lack of attention and failure to use every day
will allow joints to work loose and boiler check to fill
up with mud and scale. It should be tested every
day and worked regularly so as to keep it in good
109. Q. If an injector stops working while on the
road, what should you do?
A. Would first ascertain if sufficient water was in[Pg 94]
the tender and tender valve open, and that water was
cool enough in the tender so the injector would handle
it. Would next see that no obstruction was in the
feed pipe or strainer and that the feed pipe was free
from leaks, and that the injector was getting a sufficient
supply of steam. If the injector would not
prime, would see whether overflow or heater valve
could open wide, or if overflow pipe was obstructed.
If suction pipe was very hot would blow water back
into tank and let suction fill with cold water. If
possible, examine for obstruction in the steam priming
tube and water tubes. If it would prime and fail to
deliver water to the boiler, would see that the delivery
tube was not obstructed and then look for trouble at
the boiler check. An obstruction in the tubes would
stop the injector working at once, while wear of the
tubes or filling up with scale would affect the injector
110. Q. What are the advantages of the combination
boiler check and stop valve?
A. A combination boiler check is fitted with a
valve similar to a globe valve and can be closed at
will. Its advantage is that the boiler pressure can be
shut off from the check and the valve repaired without
cooling the boiler. This hand-operated valve can be
closed to prevent the boiler water passing back in
case the check valve sticks up and allows the boiler
water to pass back to the injector when not working.
111. Q. How can a disconnected tank valve be
opened without stopping?
A. Close the overflow or heater valve and turn
steam back toward the tank; this will usually lift the
valve from its seat or turn it around so it opens.[Pg 95]
112. Q. What comprises the steam heat equipment
on a locomotive?
A. A globe valve throttle at the boiler, a reducing
valve, a steam gauge connected to the steam heat
pipe and the proper piping and hose connections.
113. Q. What pressure is carried in the steam
heat pipe, and how is it controlled?
A. From twenty to sixty pounds in the train pipe,
depending on the length of the train, and is controlled
by the regulating valve.
114. Q. What would you do in case the regulating
valve failed to operate?
A. In case the regulating valve would not admit
sufficient steam to the train pipe, would take it apart
and block the steam valve open. If the pressure ran
up too high in the steam heat train pipe, would control
it with the steam throttle at the boiler head.
115. Q. How does the steam heat reducing valve
control the pressure?
A. The inlet valve for live steam is opened and
closed by the movement of a metallic diaphragm in
the valve which is opened by spring pressure on one
side and closed by steam pressure on the other side.
To regulate this pressure, stiffen the spring to carry
more, weaken it to carry less by turning the handle
connected to this spring either up or down.
116. Q. If steam heat gauge showed the required
pressure and cars were not being heated properly,
how would you proceed to locate the trouble?
A. First note where the hand on the steam heat
gauge stands when steam is shut off; if it does not[Pg 96]
drop back to zero see how much it lacks of this and
note the rise of pressure shown by the gauge when
steam is turned on. This is to test the gauge. If
gauge is not correct, pay no attention to it, but send
back steam enough to heat the train. Over sixty
pounds will usually make the hose couplings on the
cars rise up and leak at the joints.
117. Q. When engine is detached from the train,
what precaution should you take to prevent freezing
of the steam heat train pipe? What to prevent damage
of steam heat hose?
A. Open steam throttle to allow a very little steam
to pass into steam heat train pipe to prevent its freezing.
If end of hose is liable to strike frogs or crossings,
hang it up where it will be safe.
118. Q. What constitutes abuse of an engine?
A. Improper use of injector by filling boiler at a
rapid rate when drifting or standing in a siding, unless
you have a heavy bright fire to heat the injected
water to the boiler temperature as fast as it comes
into the boiler. Excessive use of the blower, especially
with a light fire or when cleaning the fire. Improper
attention to machinery, such as keeping parts
not properly lubricated, rods not properly keyed,
wedges not adjusted, carrying too much or too little
water in the boiler, working water through the cylinders,
allowing engine to slip unnecessarily, use of
sand on one rail only or otherwise improperly; being
careless in any way where care is required and not
properly reporting the necessary work so it can be
119. Q. How are accidents and breakdown best
A. By inspection both at and after leaving terminals,
frequently while on the road, keeping all parts
properly adjusted, water in the boiler at the proper
level and using good judgment in the handling of the
engine and train. It is much better to use care and
prevent accidents than to make repairs after they
120. Q. What are the duties of an engineman
when leaving his engine at the terminal?
A. Place her on the proper track to be turned over
to the hostler, leave throttle closed securely, reverse
lever in center notch, cylinder cocks open, and lubricator
feeds to steam chest and cylinders closed. The
boiler should be full of water and sufficient fire to
maintain steam pressure until fire is knocked out.
Call fireman's attention to anything of special importance.
Inspect the engine very thoroughly, ascertain
whether any tools or signals have been lost on
the trip and make a full report of the condition of
the entire locomotive.
121. Q. What is the most important bolt or nut
on the locomotive?
A. The loose one. It should be cared for immediately.
122. Q. In reporting work on an engine, is it
sufficient to do it in a general way, such as saying:
"Injector won't work," "lubricator won't work,"
"engine won't steam," "engine blows," etc.? Or
would you report each special defect so it could be
located after the engine was put in roundhouse or on
designated track whether it had steam pressure in
boiler or not?
A. No. Report all defects noticed so plainly that
they can be located by the repair man without un[Pg 98]necessary
work and whether there is steam in the
boiler or not at the time repairs are to be made. If
the engine blows, make a test to locate the blow and
report it correctly. Also report any unusual feature
in the operation of the engine during the trip.
1. Q. Wherein do compound locomotives differ
from ordinary or simple ones?
A. Simple engines take live steam from the boiler
and after one expansion in a single cylinder it is
exhausted to the atmosphere. A compound engine
has two cylinders, sometimes one on each side of the
locomotive; other types have four cylinders or two
on each side of the locomotive. The live steam first
passes into one cylinder, expanding down for a portion
of its pressure, and then being allowed to pass
into the second cylinder where it expands a second
time, thus getting two expansions from each volume of
live steam. Both simple and compound locomotives
consist of two engines coupled to the same set of
driving wheels. Balanced compounds have four sets
of main rods and crank pins. Mallet compounds have
two complete sets of engines under one boiler.
2. Q. Why is one cylinder on a compound locomotive
called the high-pressure cylinder and the other
one a low-pressure cylinder?
A. The high-pressure cylinder takes that name
because it works live steam direct from the boiler at
high pressure. The low-pressure cylinder receives the
steam after the first expansion and works with a low[Pg 99]
pressure. It is always larger than its companion high-pressure
cylinder in order to get the same power from
the low-pressure steam.
3. Q. In the Schenectady two-cylinder compound,
what is the duty of the oil dash-pot?
A. It is intended to prevent the too rapid movement
of the intercepting valve which might damage
the valve or seat, and it is necessary that the dash-pot
should be full of oil to make it work properly.
4. Q. Explain how a Schenectady two-cylinder
compound may be operated as a simple engine.
A. To operate the compound as a simple engine,
the separate exhaust valve is opened which will
cause the intercepting valve to move and stay in
position to allow the high-pressure cylinder to exhaust
direct to the atmosphere and admits live steam at a
reduced pressure to the low-pressure cylinder. This
should be done when starting a train or when moving
very slowly and about to stall on a grade. The engine
should not be operated simple while running except
when at low speed.
5. Q. Explain how a two-cylinder compound is
changed from simple to compound.
A. Place the handle of the three-way cock or
simpling valve in the cab so as to release the air from
the cylinder of the separate exhaust valve. A coiled
spring will then close this valve. This permits the
exhaust steam of the high-pressure cylinder to accumulate
in the receiver until sufficient pressure is
obtained to force the intercepting valve into compounding
position. This shuts off live steam from
the low-pressure cylinder and allows exhaust steam[Pg 100]
from the high-pressure cylinder to feed through the
receiver into the low-pressure steam chest.
6. Q. How should a compound engine be lubricated?
A. One-third more oil should be fed to the high
than the low-pressure cylinder, using more oil at high
speed than at slow.
7. Q. Why feed more oil to high than to a low-pressure
A. Because some of the oil from the high-pressure
cylinder follows the steam into the low-pressure
8. Q. How would you lubricate the valve of low-pressure
cylinder if the oil feed became inoperative
on that side?
A. Feed an increased quantity through the oil
pipe to the intercepting valve. Shut the engine off
occasionally and cut into simple position. Oil will
then go direct from the intercepting valve into the
low-pressure steam chest and cylinders. This would
avoid going out on steam chest to oil by hand.
9. Q. How much water should be carried in the
boiler of a compound locomotive?
A. A very moderate level, never allowing it to
get so high that moist steam will pass through the
cylinders, because for satisfactory service a compound
engine should always have dry steam.
10. Q. How should a compound locomotive be
started with a long train?
A. In simple position with cylinder cocks open.[Pg 101]
11. Q. When drifting what should be the position
of the separate exhaust valve, the cylinder and port
A. Open position.
12. Q. What will cause two exhausts of air to
blow from the three-way cock or simpling valve in the
cab when the engine is being changed to compound?
A. A sticky exhaust valve. It does not move
when air is first discharged. The second exhaust
comes when it does move.
13. Q. What does steam blowing at the three-way
A. The separate exhaust valve not seating properly
caused by stuck valves, a weak or broken spring,
or the packing rings of separate exhaust valve leaking.
14. Q. What can be done if the engine will not
operate compound when the air pressure on the separate
exhaust valve is released by the three-way cock?
A. The separate exhaust valve has failed to close.
Try jarring it with a hammer on the front side, near
the exhaust valve. With a bad case, take the valve
out, clean it and replace, if not broken.
15. Q. If the engine stands with high-pressure
side on the dead center and will not move when given
steam, where is the trouble, and what may be done
to start the engine? Why?
A. The intercepting valve is stuck in compound
position, so live steam cannot get to the low-pressure
cylinder. In a case of this kind, close the throttle,
open cylinder and port cocks; when all pressure is[Pg 102]
relieved, use a bar to move forward the rod that
works through the oil dash-pot, thus moving the valve
to simple position and steam will pass to the low-pressure
cylinder as soon as throttle is open. The
engine will not start, because with the low-pressure
piston on the quarter, steam must be admitted to its
cylinder to start the engine.
16. Q. In the event of a breakdown, how should
A. The same as a simple engine with separate
exhaust valve open, so engine will work simple instead
17. Q. What may be done to shut off steam pressure
from the steam chest and low-pressure cylinder?
A. To shut off steam from the low-pressure chest,
pull out the rod that runs through the dash-pot as
far as possible and fasten it in this position. Then
open the separate exhaust valve.
18. Q. Is it important that air be pumped up on
a two-cylinder compound before the engine is moved?
A. Yes. Because the separate exhaust valve is
opened by air pressure and the engine cannot be
simpled without sufficient pressure.
19. Q. How are the blows in a compound
A. The same as in a simple engine with the exception
that any blow on the high-pressure side will
not be heard when the separate exhaust valve is closed.
A blow on the high-pressure side will increase the
pressure in the low-pressure side, so relief valves will
pop on low-pressure side when working compound
with full throttle.[Pg 103]
20. Q. What should be done if high-pressure piston
of a cross compound is broken off the rod, or if
the high-pressure or low-pressure cylinder head is
A. Cover the ports on that side, open separate
exhaust valve and run in; use live steam in low-pressure
cylinder only, for the broken piston. With
broken cylinder head, would cover ports on that side.
Open separate exhaust and run in with low-pressure
side. Would not take down main rod, but would
take out pop valves in both cylinder heads and see
that the cylinder is properly oiled. For low-pressure
head broken, would cover ports on that side, open
separate exhaust valve and use high-pressure side;
need not take down main rod, but would see that the
cylinder is well oiled.
21. Q. In the event of separate exhaust valves
failing to work when throttle is wide open, what can
be done to assist in opening?
A. Ease throttle off very fine to reduce the receiver
pressure; in a moment or two the separate
exhaust valve should then move. If this did not
work, would shut off entirely, even at the risk of
stalling, as in that event the train could be started
again with engine cut in simple.
22. Q. If a transmission bar on a cross compound
is broken, what would you do for the right side? For
the left side?
A. For right side would cover ports on that side,
take out pop from cylinder head, open separate exhaust
and run in with other cylinder. For left side,
cover ports and fasten valve stem same as for right
side. Would leave main rods up, keep separate exhaust
open in both cases and see that cylinder is
well oiled.[Pg 104]
23. Q. In the event of a cross compound beginning
to jerk badly and cylinder head pops in low-pressure
cylinder popping, where would you look for
A. That either the high-pressure valve or piston
packing was blowing live steam into the receiver and
then into low-pressure steam chest. If possible would
locate trouble and report accordingly.
24. Q. If during a trip you found the piston valve
rings of a cross compound were broken, what would
A. If nothing but rings were broken, would reduce
boiler pressure about 25 per cent. and go on with my
train if possible.
25. Q. If piston valve on cross compound was
broken so it became necessary to remove it, what
should you do?
A. Remove the broken piston valve, reduce boiler
pressure to 100 pounds and proceed.
26. Q. What is the difference between a Vauclain
four-cylinder compound, a four-cylinder tandem, a
balanced and a Mallet compound in their arrangement
A. A Vauclain compound has two cylinders on
each side, one above the other, and both piston rods
connected to one cross-head. A four-cylinder tandem
has four cylinders, the high pressure being ahead of
the low pressure on each side, and both pistons connected
to one piston rod and one cross-head. A
balanced compound has four cylinders, the two high-pressure
cylinders being between the frames, each
having a main rod connected to a crank axle. The
two low-pressure cylinders are located outside the[Pg 105]
frame, each having a main rod and crank pin connected
to the driving wheel center. A Mallet compound
consists of two separate and independent engines,
one fixed to the boiler, the other swinging from
a center and sliding back and forth under the front
end of the boiler. The rear engine works steam at
high pressure; steam from this engine exhausts
through a receiver pipe having flexible joints to the
forward engine which works the steam at low pressure,
then exhausts it to the front end and stack.
27. Q. How many main steam valves has each
A. The Vauclain has one valve on each side, distributing
steam to the high and low-pressure cylinder
on that side. The four-cylinder tandem has two
valves on each side, one for each of the two cylinders.
A Baldwin balanced compound has two valves the
same as the Vauclain. The American balanced compound
has four valves, one for each cylinder, the two
valves for one side of the engine being connected to
one valve rod. A Mallet compound has a separate
valve for each cylinder the same as a simple locomotive.
28. Q. How do you test for blow in high and low-pressure
cylinder packing for each type of compound
A. Simple the engine if a cross compound, then
make test the same as for a simple engine. For
Vauclain four-cylinder compounds, test low pressure
first. A blow past the low-pressure piston will show
the same as on a simple engine; a blow past the
high-pressure piston will make the engine stronger on
that side when working a full throttle and the exhaust
from the low-pressure cylinder will be heavier. To[Pg 106]
test the valve on either side, cover the ports. Broken
packing rings in the steam valve will show a blow
in one position and be tight in another. For tandem
compound, to test high-pressure piston packing, stand
engine on the top quarter, lever in back gear, drivers
blocked and starting valve closed; remove back indicator
plug or open back cylinder cock of high-pressure
cylinder. Steam coming from the back
cylinder cock must get by the piston packing or by-pass
or starting valve. Now put reverse lever ahead
and try the other indicator plug or cylinder cock. If
a leaky by-pass valve in the front end is the trouble,
no steam will come through. To test the low-pressure
piston packing, place the engine in the same
position, lever in position to admit steam into the
front end of high-pressure cylinder. Open starting
valve, remove back indicator plug of low-pressure
cylinder and give engine steam; if steam comes from
the indicator plug opening or open back cylinder cock,
either packing or by-pass is leaking. To determine
which one, put reverse lever in another position, close
back indicator plug and open forward one; if blow
still continues, the packing rings are leaking or else
both by-pass valves. Would then inspect the by-pass
29. Q. How can the blow through sleeve packing
between high and low-pressure cylinder of the tandem
compound be located?
A. Place the engine as before on the top quarter,
put reverse lever in forward gear, see that starting
valve is closed, block the drivers or set the brakes
solid and open the throttle. Until the engine moves,
unless there is a leak, no steam can get into the front
side of the low-pressure cylinder. Remove the indicator
plug in front end of the low-pressure cylinder
for this test.[Pg 107]
30. Q. How test for piston packing blow with
A. For a Baldwin balanced compound to test the
high-pressure piston packing, place the engine with
the outside main pin on that side of the engine on the
bottom quarter, the reverse lever in the forward notch,
starting valve closed, set the brakes solid or block
the drivers, remove the indicator plug in the front
end of either the high or low-pressure cylinder. With
throttle open this will admit steam to the back end of
high-pressure cylinder. Steam coming out of this
plug opening, will indicate a leak past the piston or
the high-pressure valve. If uncertain, next test the
high-pressure valve by moving the reverse lever to
the center notch. This should cover the ports and
if the valve is tight the blow will stop. To test the
low-pressure piston, place the engine in the same
position with wheels blocked, starting valve open,
back indicator plug out; when throttle is opened, the
leaky packing will be shown by steam issuing from
the plug opening. If uncertain, the valve can be
tested by bringing reverse lever to the center of
quadrant, which will spot valve over port and if it
is tight the blow will stop. In any compound engine
a blow past the high-pressure packing tends to increase
the pressure in the low-pressure cylinder. A
blow past the low-pressure packing can always be
heard at the exhaust, and is usually on both forward
and back strokes, while a blow past the by-pass valves
or valve bushings occurs at a certain part of a complete
31. Q. In case it was necessary to disconnect on
one side of a compound engine, how would you cover
ports and hold valves in position?
A. The easiest way is to clamp the valve stem to
hold valve in mid position; this should cover all ports.[Pg 108]
It may be necessary to take off head of piston valve
chest and block in there.
32. Q. Is it a
to work a compound engine in short cut-off? Why?
A. Yes. If cut-off is too short the proper proportion
of steam passing the throttle will not get to the
low-pressure cylinder. The work should be divided
between the two cylinders on same side.
33. Q. In what way do the Mallet or articulated
compounds differ from other steam locomotives in the
distribution of the steam?
A. Mallet compounds have two separate and complete
engines under one boiler. The rear engine has
a rigid connection to the back end of the boiler; this
engine works boiler steam direct the same as a simple
locomotive. Under the front end of the boiler is another
engine so constructed that the entire front engine
can move from side to side under the boiler,
having a hinged connection at the front end of the
rear engine to allow the locomotive to pass curves
more easily. The front engine takes the exhaust
steam from the rear engine through a flexible pipe or
receiver and works it through a larger set of cylinders
and thus compounds the steam. From the low-pressure
cylinders the steam is exhausted to the atmosphere
through the stack.
34. Q. How do you get the use of both engines
when starting a train?
A. To get steam into the low-pressure cylinders
before the high-pressure engine has exhausted, some
types of the Mallet compound have a live steam pipe
with a valve in the cab to admit boiler steam to the
receiver pipe and thus get the use of the front engine[Pg 109]
in starting a train. The American Locomotive Company
articulated compounds have an intercepting
valve similar to the one used in the Richmond cross
compound, located between the exhaust passage of
the rear engine and the flexible receiving pipe of the
front one. This intercepting valve when in SIMPLE
position, allows the high-pressure cylinders of the rear
engine to exhaust directly to the stack instead of into
the receiver, and feeds boiler steam at a reduced
pressure into the receiver pipe for the low-pressure
cylinders without giving any back pressure on the
high-pressure pistons. This increases the power of
the complete locomotive about 20 per cent. When
in compound position, the intercepting valve cuts off
the supply of live steam to the receiver pipe and
forces the exhaust steam to go to the low-pressure
35. Q. How is the American articulated compound
changed from compound to simple, and back to compound
A. To work the locomotive simple, place the
handle of operating valve in the cab to point toward
the rear. This admits steam against the piston that
operates the emergency exhaust valve and opens it.
Exhaust steam from the high-pressure engine can pass
to the exhaust nozzle instead of to the low-pressure
engine. The intercepting valve then moves over so
that live steam reduced to 40 per cent. of boiler
pressure goes through the receiver pipe to the low-pressure
engine. To work compound, place the handle
of the operating valve to point forward. This will
exhaust the steam, holding the emergency exhaust
valve open; a spring and the pressure of the steam
exhausted from the rear engine will close the emergency
exhaust valve and build up a pressure against[Pg 110]
the intercepting valve that will open it so exhaust
steam from the rear engine will go to the forward one
and at the same movement close the reducing valve
so no more live steam goes to the receiver.
36. Q. When is it necessary to use the operating
valve to change the locomotive from compound to
simple, or from simple to compound?
A. When giving the engines steam to start, the
intercepting valve should automatically go to simple
position until exhaust steam from the rear engine
builds up a receiver pressure that shifts the valve to
compound; if it does not, use the operating valve.
When moving less than four miles an hour or when
about to stall on a grade, set the engines working
simple; changing to compound when the danger of
stalling is over or the speed is more than four miles
an hour. If there is no intercepting valve to furnish
live steam to the forward engine, open the starting
valve to admit live steam to the receiver pipe and
37. Q. If in starting the locomotive the forward
engine does not take steam, what is the trouble?
A. The reducing valve may be stuck shut on account
of being dirty or stuck on the stem of the intercepting
valve. In case the reducing valve is stuck
shut, the head of the dash-pot can be taken off and
the valve worked back and forth to loosen it. The
intercepting valve should be liberally oiled just before
starting and occasionally during long runs to keep it
free from sticking.
38. Q. Why does the Mallet compound have more
power when working simple than compound?
A. If a starting valve is used to admit live steam[Pg 111]
to the receiver pipe and thence to the low-pressure
engine, this gives a higher pressure to the low-pressure
cylinders. If an intercepting valve is used, the open
emergency exhaust valve allows exhaust steam from
the rear engine to go direct to the stack; this takes
away the back pressure of the receiver steam from
the high-pressure pistons, about 30 per cent. of the
boiler pressure, and thus adds to the power of the rear
engine. The reducing valve when feeding live steam
gives about 40 per cent. of boiler pressure to the low-pressure
engine instead of the 30 per cent. it gets
from the receiver; the added power of both engines
working simple is about 20 per cent. over the compound
39. Q. What is the duty of the by-pass valves on
the sides of the low-pressure cylinders? Should they
be kept clean of gum and grit?
A. These valves are connected to the steam ports
at each end of the cylinders and open to allow air
and steam to pass from one end of the cylinder to the
other; away from the moving piston when the engine
is drifting. If not kept clean they may stick open;
when working steam the engine will blow badly; if
they stick shut the engine will pound when drifting.
40. Q. In what position should the reverse lever
be when the steam is shut off and the engine drifting?
A. Below three-quarters of full gear, so the valves
will have nearly full travel.
41. Q. Why should the power reversing gear of
the Mallet compound always have its dash-pot cylinder
full of oil?
A. To prevent the too rapid movement of the
reverse gear piston and its damage.[Pg 112]
42. Q. In what position should the engines stand
to test for blows in valves and piston packing?
A. Put the operating valve, or starting valve, in
simple position. Spot the engine in the proper position
and test each engine for blows the same as for a
43. Q. What power is used with Ragonnet or
Baldwin power reverse gear?
A. Air pressure.
44. Q. Can and should steam pressure be used?
A. Yes. However, steam should never be used
except in an emergency when air is not available.
45. Q. What precaution should be taken regarding
steam check and throttle?
A. That they are tight and check working properly,
to insure that steam is kept from entering main
reservoir, for if it should do so it would burn out the
gaskets in the air brake equipment, allow moisture to
accumulate, which would result in freezing and bursting
of equipment as well as being dangerous.
46. Q. What would cause the gear to fail to hold
links in intended cut-off, and allow them to raise and
lower without operating valve in the cab being
A. Leaks in main valve and piston packing.
WALSCHAERT AND BAKER-PILLIOD VALVE GEARS
1. Q. Give a brief explanation of the Walschaert
A. The Walschaert gear has an eccentric crank
attached to the end of the main pin on each side of
the locomotive, with an eccentric rod from this pin
to the connection at the bottom end of the link. This
eccentric is located so it serves for both forward and
back motion. The link swings on a center trunnion
and cannot be moved up and down as the Stephenson
link, but the link block can be moved from one end
of the link to the other to reverse the engine; or part
way toward the center of the link to change the cut-off.
A radius rod connects the link block to the valve
stem. There are two motions given to the valve stem,
one from the link block which regulates the travel of
the valve for the cut-off and reversing; the other
motion is from a connection with the cross-head which
gives the valve a positive motion to take care of the
lap and lead. To give this motion there is used a
combination lever or a lap and lead lever connected
to a cross-head arm by the union link.
2. Q. Is the Walschaert gear direct or indirect?
A. It is direct when the link block is below the
center of the link; it is indirect when the link block is
above the center of the link.
3. Q. What are the principal differences in the
location of the Stephenson and Walschaert gears, and
what advantages does this give the Walschaert?
A. The Stephenson gear is placed between the
main frames and employs two eccentrics, with straps
and rods on each side of the locomotive; one for[Pg 114]
forward and one for backward motion. The
Walschaert gear is placed outside the driving wheels
and frame, has but one eccentric, which is a simple
arm connected to the outside end of the crank pin
for both forward and back motion. The links are
set above the wheels on a level with the steam chest,
the combination lever next to the cross-head. This
gives it an advantage of a better chance to inspect all
parts, the eccentric connections are much lighter and
direct, which makes them less liable to wear or breakdown,
and the valve has a constant lead.
4. Q. How is the lead affected by movement of
the reverse lever with the two gears?
A. With the Stephenson gear the lead increases
as the reverse lever is hooked toward the center in
both forward and back motion. With the Walschaert
gear the lead is the same in all positions of the lever,
so that the lever is used to reverse the engine or adjust
5. Q. In reversing, how do the two gears differ as
to the movement of the link and link block?
A. With the Stephenson gear, when reversing, the
link is raised and lowered, bringing the block which
is not moved by the reverse lever under control of
either the forward or back-up eccentric as is desired
to move the engine the proper way. With the
Walschaert gear the link is not moved by the reverse
lever, but the link block is raised and lowered in the
link; the position of the block above or below the
center of the link controlling the direction of motion.
6. Q. What would you disconnect if the eccentric
crank, eccentric rod, or the arm at the bottom of the
link should break?[Pg 115]
A. Would remove the broken parts, disconnect
the link lifter from the radius rod and block the link
block in the center of the link; the combination lever
would then move the valve twice the amount of its
lap and lead, which would be sufficient to provide for
lubricating the cylinder.
7. Q. If the main crank pin was broken?
A. Take down eccentric rod, eccentric crank, main
rod and all connecting rods, block cross-head, disconnect
from end of radius rod, chain it to running
board and block steam valve to cover ports.
8. Q. Broken cross-head pin, main rod, strap or
A. Take down main rod, block cross-head, disconnect
front end of radius rod and chain to running
board and block the valve to cover ports.
9. Q. With a broken combination lever, union link
or cross-head arms, what would you do?
A. Would disconnect the forward end of the radius
rod and secure it to the running board with a small
chain, wire or rope, remove all broken parts, take off
the combination lever, even if not broken, secure the
valve in its central position, loosen cylinder head to
provide for lubrication, leave up main rod and proceed
on one side. If valve was blocked to open rear
port slightly, this would provide for lubrication and
the cylinder head need not be loosened.
10. Q. If the radius rod on Walschaert gear is
disabled, what should be done?
A. If broken in front of the link block, take off
the broken part by disconnecting from combination
lever, take down eccentric rod, fasten valve to cover[Pg 116]
ports and proceed on one side. If broken back of
the link block, block the link block in the desired
position and proceed with both sides.
11. Q. What would you disconnect with a
Walschaert gear if a valve yoke should break?
A. Disconnect the forward end of the radius rod,
suspend it from running board, block the valve, provide
for lubricating the piston and proceed.
12. Q. How proceed with a broken reach rod?
A. Remove the reach rod, block links on lower
side to hold them in running position for proper direction.
Unless radius rod lifters can be uncoupled,
leave a little slack in the blocking.
13. Q. How can you tell without opening the
steam chest if the valve covers the port with Stephenson
gear? With Walschaert gear?
A. Place the rocker shaft vertical with Stephenson
gear. Place the combination lever vertical with reverse
lever in mid gear so the link block is in the
center of Walschaert link.
14. Q. What is the Baker-Pilliod valve gear?
A. It is an outside gear with an eccentric crank,
similar to the Walschaert gear, but without a reversing
link. The motion is reversed by means of a reversing
yoke instead of a link; the cut-off is changed in the
same manner. It uses a combination lever connected
with a union link to its cross-head arm. In case of
breakdown remove the broken parts the same as described
for Walschaert gear, blocking the reversing
yoke, if necessary, in the proper position.[Pg 117]
15. Q. Is the Baker gear a direct or an indirect
A. It is direct, going ahead for an inside admission
and indirect backing up, and just the opposite for the
outside admission type.
16. Q. What parts of the Baker gear take the
place of the link which is used by the Stephenson or
A. The radius bars and reverse yoke.
17. Q. What relation to the main pin is the eccentric
crank set to?
A. The eccentric crank always follows the main
18. Q. Should the eccentric rod or eccentric crank
break how is the engine put in condition to proceed?
A. The disabled side can have lap and lead travel
and a port opening equal to the lead for all cut-offs.
First block the bell crank by using a "U" bolt (which
should be provided) in the holes placed in the gear
frame for this purpose. Throwing reverse lever in
mid-gear will help to get bell crank in position to
block. Second, take down broken parts. Third,
knock out back pin of short reach rod and throw
reverse yoke in forward motion against gear frame.
19. Q. What is to be done should a gear connection
A. Do the same as for a broken eccentric or crank.
20. Q. What is to be done should the upper part
of gear connection rod break?
A. If break is close to the middle pin, do the same
as for a broken eccentric rod and also tie lower end[Pg 118]
of gear connection rod to keep it from swinging. If
break is near the top and below the jaw, first block
the bell crank and wire the connection rod fast to
radius bars. If break is through top jaw, do the same
as for broken eccentric rod.
21. Q. What is to be done should a radius bar
A. Do the same as for broken eccentric rod.
22. Q. If the horizontal arm of bell crank should
A. Same as broken eccentric rod.
23. Q. What is to be done should the vertical arm
or bell crank break?
A. Take down union link combination lever and
valve rod, then block valve over ports by using set-screw
in valve stem cross-head provided for that
24. Q. Should you break cross-head arm or union
link, what would you do?
A. If rod be provided to secure lower end of the
combination lever to guide yoke, remove broken parts
and proceed with full train, working engine at long
cut-off. Otherwise would remove broken parts, combination
lever and valve rod, cover ports, and proceed
on one side.
25. Q. What do you do if a union link should
A. Same as for a broken cross-head arm.
26. Q. What is to be done if a combination lever
should break?[Pg 119]
A. Tie combination lever plumb, same as for a
broken cross-head arm, if it is possible. If not possible,
take down the combination lever and valve rod
and cover the ports.
27. Q. What is to be done if a valve rod breaks?
A. Take down the broken parts and cover ports,
leaving the rest of the gear intact.
28. Q. What is to be done if a reverse yoke
A. If lugs for holding reach rod breaks, block
yoke securely at whatever cut-off you wish to work
the engine and take down the short reach rod. If
break is below the lugs, do the same as for broken
29. Q. What do you do if reach rod should
A. If short reach rod breaks, block the yoke at
cut-off desired and wire fast so it cannot move. If
main reach rod breaks, block between tumbling shaft
arm and cross-tie brace, wiring same securely.
30. Q. What is to be done if the engine breaks
down other than valve gear?
A. In this case do the same as for any other valve.
1. Q. If the eccentric crank or eccentric rods fail?
A. Disconnect the eccentric rod from crank,
radius hanger and transmission yoke, tie up the
hanger and yoke, clamp valve central position and
2. Q. If radius hanger fails?
A. Disconnect the hanger from rod and take down
eccentric rod, clamp valve in central position and
3. Q. If transmission yoke fails?
A. Disconnect from the eccentric rod and clamp
valve in central position and proceed.
4. Q. If horizontal arm of bell crank fails?
A. Disconnect the yoke from the eccentric rod,
tie up to clear, clamp valve in central position and
5. Q. If vertical arm to bell crank breaks?
A. Clamp valve in central position and proceed.
Take the broken arm down if necessary.
6. Q. If one auxiliary reach rod or reverse shaft
A. Block both link blocks in same position of
links, and in such a position as to give port opening
enough to start train and control speed by throttle.
7. Q. If main reach rod, or middle arm to reverse
shaft fail? If both auxiliary reach rods fail?
A. Block link blocks in full valve travel, controlling
power and speed with the throttle.
1. Q. What produces friction, and what is the
result of excessive friction?
A. Friction as considered in locomotive service is
produced by one body being rubbed across the sur[Pg 121]face
of another when they are held in contact by
pressure, and the result of excessive friction is heat
more or less intense and the destruction of the journal
and its bearing or the roughening of the sliding
2. Q. What is lubrication and its object?
A. The object of lubrication is to interpose a film
of oil, grease or some lubricant between the two surfaces
that will prevent these rubbing surfaces from
coming into too intimate contact.
3. Q. What examinations should be made by the
engineer to insure successful lubrication?
A. See that all oil holes are open, cups filled and
in good working order, the packing in cellars evenly
put in and in contact with the journal. That waste
on top of driving or truck boxes is in proper shape,
also that grease cups are filled, and the plugs and
jam nuts in good shape, and that the grease cellars
contain sufficient grease for the next trip.
4. Q. How should feeders of all oil cups be adjusted?
A. To feed as small a quantity of oil as possible
and regularly to give perfect lubrication.
5. Q. Why is it bad practice to keep engine oil
close to boiler in warm weather?
A. The oil is thinned to such a degree by the heat
of the boiler that it runs off as soon as applied, and
very often a hot bearing is the result.
6. Q. In what manner would you care for a hot
bearing if discovered on the road?
A. Use as much time as available in cooling the[Pg 122]
same, making sure that all moving parts are free and
carefully lubricated before proceeding.
7. Q. What kind of oil should be used on hot
A. Use engine oil unless the temperature of bearing
consumes it, when a small quantity of valve oil
may be used while the bearing is warm enough to
make this oil flow. The valve oil must be removed
as soon as the bearing cools to prevent reheating.
8. Q. At completion of trip what is necessary?
A. Close all adjustable feeds and examine all lubricated
parts by contact with the hand to determine
that they are not above running temperature.
9. Q. How would you determine what boxes to
report examined? Why not report all boxes examined?
A. By placing the hand on driving box, on hub
of engine truck wheel and on top of tender truck
boxes nearest the brass, and would not report them
examined unless the temperature of same was above
running heat. It is not necessary to report all boxes
examined, because they do not all give trouble at the
same time. If this report was made, it would appear
that a proper inspection had not been made and
would result in unnecessary work and waste of material.
10. Q. Why is it bad practice to disturb the packing
on top of driving and engine truck boxes with
spout of oil can when oiling engine?
A. This packing is put on top of boxes to assist
in keeping dirt and dust out of oil holes, also to aid
in gradual lubrication from the top. If this packing
is disturbed it will permit dirt and grit to work into[Pg 123]
oil holes and on the bearings as well as feed the oil
away too rapidly.
11. Q. How do you adjust grease cups as applied
A. Screw down plug until you feel a slight resistance
from the grease, stop when grease shows
between brass and pin; this should be sufficient over
12. Q. Is it usual for pins to run warm when
A. Yes; grease does not work properly until it
gets warm enough to flow readily over the bearing.
13. Q. What effect does too much pressure produce?
A. Wastes grease and increases the friction until
the surplus amount is worked out so the bearing runs
free on its journal.
14. Q. Is it necessary to use oil with grease on
15. Q. When an engine is equipped with Elvin
driving box lubricator, how can you tell whether a
sufficient amount of lubricant is in the grease receptacle?
A. The indicator wire fastened to the bottom of
the grease cellar indicates the amount of grease left
in the cellar.
16. Q. Why should engine oil not be used on
valves and cylinders?
A. Engine oil loses its lubricating qualities before
it gets up to the temperature of the valves and cylinders
when they are working steam.[Pg 124]
17. Q. At what temperature does engine oil lose
its lubricating qualities? At what temperature for
A. Engine oil begins to separate and give off gas
at 345 degrees F. The temperature of steam at 120
pounds is 350 degrees F., while valve oil has a flash
test of 520 degrees F. The temperature of steam at
235 pounds is 431 degrees F., much lower than the
flash test of valve oil.
18. Q. How and by what means are valves, cylinders
and the steam end of air pumps lubricated?
A. By a sight-feed hydrostatic lubricator.
19. Q. What is the principle on which a lubricator
operates. How does the oil get from the cup to the
A. The lubricator is located in the cab so there is
a gradual descent in the oil pipe from the lubricator
to the steam chest. Above the oil reservoir is a condenser
that is kept filled with water condensed from
steam fed from the boiler. The pressure of this water
comes on the oil in the oil tank below it, forcing oil
through the sight-feed valves; it then passes up by
the sight-feed glasses to the oil pipe and steam chest.
The use of the glasses is to make the drop of oil
visible as it leaves the sight-feed nipple so the amount
of oil fed can be regulated. Steam from the boiler
fed to the lubricator at boiler pressure through the
equalizing tubes balances the pressure which comes
from the steam chest when the engine is working
20. Q. How should the lubricator be filled?
A. First close all valves connected with the lubricator,
open drain plug and remove filling plug, allow[Pg 125]ing
water to escape until oil appears with it. Drain
plug should then be closed. Fill the oil tank in the
usual way, being careful not to overflow it; then replace
filling plug. If the supply of oil is insufficient
to fill the lubricator, water can be used to finish it,
as the lubricator will begin feeding sooner when
21. Q. After filling lubricator, what should be
A. Open the steam throttle to the lubricator wide,
then carefully open the water valve, but do not open
the feeds until sure the chamber in the glass is filled
22. Q. How long before leaving terminal should
the feed valves be opened? Why?
A. About fifteen minutes; this time is necessary
to allow oil to feed through the oil pipe and reach the
23. Q. How many drops should be fed per minute?
A. From one to seven, timed by the watch, depending
on conditions. Cylinders of large size require
more oil than smaller ones.
24. Q. If lubricator feeds regularly when working
steam and too rapidly after shutting off, what is the
A. The opening in the choke plug at the lubricator
or through the steam valves at the steam chest is too
large and should be reduced to the proper size by
applying new chokes or valves.
25. Q. When valves appear dry while using steam
and the lubricator is working all right, what would
you do to relieve these conditions?[Pg 126]
A. Ease off throttle for a few seconds to reduce
the steam chest pressure and drop the reverse lever
a few notches to give the valve a longer travel; oil
held in the pipes will then flow down.
For Inspection of Locomotive Boilers and Safety
1. Q. What is the purpose of the federal rules
and regulations for inspection of locomotive boilers?
A. So that all railroads
under the laws of the United States government, would be obliged to
maintain their boilers in a safe working condition.
2. Q. What is the purpose of the quarterly and
monthly interstate inspection cards placed in the cab
of the locomotive?
A. So that the federal inspector or engineer may
see that the locomotive boiler has received its monthly
or quarterly inspection.
3. Q. What constitutes a safety appliance, as applied
to a locomotive?
A. Any appliance that is placed on a locomotive
for the purpose of protecting the employees from personal
4. Q. Name some of the safety appliances found
on a locomotive?
A. Shield for tubular glass lubricators, also shields
for water glass, automatic couplers, with lever attachments,
air brakes, etc.
5. Q. In what condition should safety appliances
be maintained?[Pg 127]
A. They should be maintained in first class condition.
6. Q. What should be done in event of any of
the safety appliances being damaged while engine is
in service so as to render it unsafe?
A. Warn all employees whose duties require them
to work around the locomotive of its unsafe condition,
then make report to those in authority so that it
may be taken out of service until repairs are made.
7. Q. What effort should be made on the part of
the engineer to prevent persons using a safety appliance
which he knows is damaged and unsafe?
A. He should use such precaution as in his judgment
would protect from injury all persons who are
on or around the locomotive.
8. Q. What is the duty of the engineer in event
of his discovering a safety appliance which is in an
unsafe condition when taking an engine from roundhouse
A. He should report at once to the person in
authority so that necessary repairs may be made before
engine goes into service.
PYLE-NATIONAL ELECTRIC HEADLIGHT
1. Q. Why are electric headlights applied to locomotives?
A. Electric headlights are applied to locomotives
so that the engineer may have a clear view of the
track for enough ahead of the train to enable him to
protect the company's property in his charge.
2. Q. How far ahead of the engine should the
arc headlight illuminate the track?[Pg 128]
A. Not less than from fifteen to twenty telegraph
3. Q. State how you would focus the lamp.
A. First, would adjust back of the reflector so
front edge of reflector will be parallel with front edge
of case. Second, adjust the lamp to have point of
copper electrode as near the center of reflector as
possible with carbons as near the center of the chimney
holes as you can set them. Third, have the
locomotive on straight track. Now move the base
of the lamp around until you get a parallel beam of
white light straight down the center of the track, then
tighten the lamp down.
4. Q. If the light throws shadows upon the track,
is it properly focused?
5. Q. If the light is properly focused, that is, if
the rays are leaving the reflector in parallel lines, but
the light does not strike the center of the track, what
should be done?
A. When the light rays are thrown out in parallel
lines and they do not strike the center of the track,
it denotes that the headlight case is not set straight
with the engine, and the entire case on base board
must be shifted until the shaft of light strikes the
track as desired.
6. Q. What can you do to insure a good and unfailing
light for the entire trip?
A. By carefully inspecting the entire equipment
before departing on each trip, and know that there
are no wires with insulation charred or worn off, that
all screws and connections are tight, commutator
clean and brushes set in brush holder in proper man[Pg 129]ner.
Carbon in lamp of sufficient length to complete
trip, and that the carbon will feed through the clutch
freely and rests central over the copper electrode.
Copper electrode cleaned off, oil in both bearings
and see that steam does not blow at stuffing box gland.
7. Q. What kind of oil and how much would you
use in the bearings of the electric headlight equipment?
A. Would use the best grade of black or engine
oil furnished for both bearings and only enough oil
in oil cellar that the revolving loose oil ring may trail
through the oil. When bearings are supplied with oil
cups, use a heavy oil such as good engine or valve oil.
8. Q. Why should you not use valve oil in these
A. Valve oil cannot be used
in the main bearing because of its heavy body. Valve oil
could not be carried up to shaft by the oil ring in cold
weather, as the ring will not revolve.
9. Q. What is the most vital part of the dynamo?
A. The commutator.
10. Q. What care or attention should be given the
A. The commutator must be kept clean, free from
dirt, and the mica must be kept filed a trifle below
the surface of the copper bars.
11. Q. What kind of a bearing should the brush
have on the commutator?
A. Brushes should be fitted to have a bearing with
the same contour as the commutator.
12. Q. How are the brushes fitted?
A. Brushes are fitted by cutting a strip of No. 0
sandpaper about the width of the commutator surface[Pg 130]
(have the dynamo idle), place the strips of sandpaper
under the brush, then pull the sandpaper from
left to right; continue this process until the brush has
been fitted to a true smooth bearing. Then trim about
one-eighth inch off of the front edge of the brush.
13. Q. Is it advisable to ever try to fit a brush
with a file or knife?
A. Most emphatically no. You could not get a
bearing across the brush no matter how hard you
might try with either a file or a knife.
14. Q. Why is it important to clean the scale off
of the point of the copper electrode each trip?
A. The scale on the copper electrode after it has
cooled off is a non-conductor of current, and acts as a
blind gasket between the carbon and the copper electrode.
Unless this scale is removed, the current cannot
pass between the points of carbon and electrode
and you cannot, therefore, have a light. When the
dynamo fields are compound wound, it is unnecessary
to clean scale from copper electrode oftener than
once a week, at which time copper electrode should
be removed from holder and all scale cleaned off.
(With compound wound dynamo fields the cab lamps
will continue to burn when head-lamp is extinguished
by lifting carbon by hand.)
15. Q. How should the copper electrode be
trimmed at the point?
A. The copper electrode should have about one-eighth
inch surface on the contact point.
16. Q. How far should the copper electrode project
over the holder?
A. About one inch.
17. Q. Should the electrode be raised up to one
and one-half inches, what might happen?
A. If the copper electrode was run at a point so[Pg 131]
near the clutch, the intense heat of the arc might do
to the top carbon holder and clutch.
18. Q. What regulation should be given to the
tension spring No. 93 of the lamp, and why?
A. This tension spring, No. 93, should be regulated
when the current is off the lamp and should be
adjusted only tight enough to pull the magnet yoke up
against the top stop lug on the side of lamp column.
19. Q. If this tension spring was tightened too
tightly, what might happen?
A. At usual speed between stations, the movement
of the engine would impart an added resistance
against the pull of the solenoid by the tension spring,
which would shorten up the arc and dim down the
20. Q. Is there anything else that could cause the
light to dim down when the engine is running fast?
A. Yes; if the spring No. 92-A that hold the
heel of the clutch should be too weak, the heel of the
clutch would be forced up by the motion of the locomotive;
this would release the carbon which would
fall to the point of the copper electrode, causing the
light to dim down, or, if the clutch should be used
until the sharp edge that grips the carbon should have
become worn smooth or round, the same would occur.
21. Q. If the light burns satisfactorily while the
engine is in motion, but goes out when engine is
stopped, where would you find the trouble?
A. This trouble is most always found to be caused
by the tension spring No. 93 being too weak, though
if the dash-pot plunger has become corroded until it
sticks in the dash-pot, the light will act the same as if
the tension spring were too weak.[Pg 132]
22. Q. If the dash-pot should be found stuck,
would you put oil in it?
A. Coal oil could be used to clean and cut the
dirt out of the pot and from off the plunger, but after
the dash-pot and plunger have been cleaned, all oil
must be wiped off, for oil would cause the plunger
to stick as well as collect dirt.
23. Q. If the carbon of lamp should "jig or
pound", what can be done to stop it?
A. If the carbons pound the electrode, it is evidence
that the iron armature No. 64 may be too far
out of the solenoid, or the speed of the turbine engine
may be too slow. This trouble can be remedied by
adding another link to the suspension link, which has
one end connected to the magnet yoke, the other end
being connected to the iron armature No. 64. If,
however, when the arc is formed, it is found that the
bottom end of iron armature No. 64 measures one-half
inch from bottom of solenoid, the pounding is
caused by the speed of turbine engine being too slow.
24. Q. If the copper electrode was fusing, how
would you know it?
A. When the copper electrode is fused, a green
light is always given off.
25. Q. What should be done when a green light
A. Immediately close off on the steam throttle
until a white light re-appears.
26. Q. What is the cause of the fusing of the copper
A. Usually too high speed of the armature, although
should you connect the wires up wrong that
the current flowing from the dynamo to the lamp[Pg 133]
should enter the lamp at the electrode instead of passing
through the carbon first, you would get a green
light and fuse the electrode.
27. Q. What arrangements have been made so
that you cannot connect the wires wrong?
A. The positive binding posts, both at the dynamo
and the lamp, have been provided with a much larger
hole to receive the wire than has been made in the
negative binding posts, and the ends of the positive
wire should always be bent or doubled back, so that
they will just enter the receptacle in the positive binding
posts, but cannot be connected at the negative
28. Q. Should the copper electrode and holder
become fused until no longer serviceable while on the
road, what would you do?
A. Would remove the damaged holder from the
lamp and substitute either an iron bolt of sufficient
length or a carbon, securing the improvised electrode
in the bracket of lamp same as the electrode holder
is held, only being sure that the end of the bolt or
carbon comes up into the center of the reflector and
did not rest on the base of reflector or lamp.
29. Q. What is the difference between a series
wound equipment and a compound wound equipment,
and what advantages are obtained from the
use of the compound equipment.
A. With the series wound equipment, the incandescent
cab lights burn only with the arc lamp, while
with the compound machine the incandescent lamps
are independent of the arc and can be used as desired.
30. Q. If you were running along with your light
burning steadily and nicely, then suddenly the light[Pg 134]
began to flash badly and kept it up, where would you
look for the trouble?
A. Trouble would usually be found at one of the
binding posts, where one of the binding post screws
would be found loose.
31. Q. If you were running along with light burning
satisfactorily and suddenly it went out, where
would you be likely to find the trouble?
A. You would find that either the carbon had
burned out, one of the lead wires had broken between
the dynamo and the lamp, or one of the wires had
gotten loose at the binding post and fallen out.
32. Q. If the light goes out while you are between
stations, what course should an engineer pursue?
A. If the light goes out while you are between stations
and an investigation cannot be made within a
few minutes thereafter to determine the cause, the
steam should be shut off from the turbine and the
dynamo stopped until such time when the cause of
failure can be determined.
33. Q. Why is it essential to shut off steam and
stop the equipment?
A. For the reason that if the failure was due to
a short circuit, damage might be done to the coils or
armature by overheating.
34. Q. How does the equipment act when short-circuited?
A. When there is short circuit, the engine will
labor heavily, run slow with a large volume of steam
blowing at the exhaust, there will be no light shown
either at the arc or cab lamps, and the carbon point
and cab lights will only show a dull red or go entirely
35. Q. How will the equipment act when the circuit
is broken, either by a broken disconnected wire
or a burned-out carbon?
A. With a broken circuit the engine will run noiselessly
and fast with very little steam blowing at exhaust
and no light will be seen at the arc or on cab
36. Q. If the insulation on the cab wires is worn
off until your two wires can come together either
directly or through the medium of some metallic substance,
what would occur?
A. A short circuit would result that would put out
all of your lights.
37. Q. What should be done?
A. Wrap the exposed wire, if you can locate it,
with a piece of waste, or if you cannot locate the
short circuit, disconnect one of your cab wires from
the dynamo. This would give you the benefit of the
arc lamp and you can look for the trouble at your
38. Q. If the light goes out when steam drops
back fifteen to twenty pounds, what is the trouble?
A. Either one of the governor valves is stuck shut,
short bushing No. 18 in engine cab is worn badly,
allowing wheel to drop away from the governor stand
so steam passes around wheel to exhaust, or governor
springs are too weak.
39. Q. In this case what should be done?
A. Report of the action of the dynamo should be
made upon the work book at the terminal.[Pg 136]
40. Q. If clutch rod No. 78-B should break while
on the road, what could be done to get use of the
A. A piece of wire could be used by fastening
one end around the end of top lever No. 59, the other
end being attached to clutch through eye.
41. Q. If you should lose the clothespin holder or
top carbon clutch, what could be done to get the
A. Would fasten a wire around the carbon and
top holder to keep carbon in line, being careful not
to get the wire either too tight or too loose.
42. Q. If you should lose the iron armature No.
64 in solenoid, what could be done to get use of
A. Would use a common iron bolt and suspend
same by wire in magnet.
43. Q. What would be the result if any of the
levers of the lamp should bind?
A. All levers of the lamp must work absolutely
free and must not drag, for if they are not perfectly
free the carbon cannot feed properly.
Pyle-National Electric Incandescent Headlight
44. Q. What is meant by an incandescent headlight
A. A headlight having an electric incandescent
lamp in the reflector in place of the usual oil or acetylene
gas flame, and electric instead of oil cab lamps,
the electricity being generated by a small combina[Pg 137]tion
steam-turbine and electric generator. Suitable
wiring distributes the electric current.
45. Q. In what manner does the incandescent
headlight differ from the arc headlight?
A. It is not so powerful. An incandescent or
bulb type of lamp takes the place of the arc lamp in
the headlight reflector. The current being less than
is required for an arc, is supplied by a smaller turbine.
46. Q. What type of incandescent lamp is used
in the reflector?
A. A low voltage, gas filled bulb, containing a
very compact or concentrated fillament.
47. Q. Why cannot a standard or house type
of lamp be successfully used in the reflector?
A. Because the fillament or light-giving wire inside
the bulb is not sufficiently compact or concentrated to
reflect the light in the form of a beam. The voltage
of the house lamp is also too high to be used on a
48. Q. How is the lamp held in place in the reflector?
A. By the usual socket, into which the lamp
screws. The socket is a part of the focusing device,
one type of which holds the lamp in a horizontal position,
while in the other the lamp is held vertically or
49. Q. Before turning the steam into the turbine,
what precautions should be observed?
A. The turbo-generator should be lubricated by a
small amount of black or engine oil, placed in the
cup on the turbine or steam end. On the generator
end, the oil should be maintained within one-half inch
of the top of the hinge-cover cup; using black oil.[Pg 138]
The drainage of the steam end is cared for automatically
by a three-eighth inch drain pipe without a valve.
The pipe should be kept open.
50. Q. How do you proceed when you wish to use
A. Open the globe valve in the steam pipe to the
turbo-generator, at least two turns. The water-glass,
steam and air gauge lamps in the cab, and the number
indicator lamp in the headlight case should light up
as soon as the turbo-generator reaches full speed. A
double-throw knife switch in the cab controls the
headlight. In one position the switch gives the full
brilliancy of the headlight. The opposite or "dimmer"
position reduces the brilliancy about one-half.
When the switch bar is in neither position the headlight
is entirely out, and only the number lamp is
burning. The classification lamp, lubricator and order
or reading lamp, are controlled by a small switch on
the socket of each lamp.
51. Q. For what purpose is the dimmer, and how
does it operate?
A. It is to reduce the intensity of the headlight
when locomotive is in yards or around stations. It
consists of a small resistance tube in the wiring circuit,
and with the cab switch in dimmer position, a
portion of the current is converted into heat instead
52. Q. How is an incandescent headlight focussed?
A. By moving the lamp in its position in the reflector
until the most brilliant and compact beam of
light is obtained. If the beam does not strike the
track centrally, or as high or low, the headlight case
must be moved on its platform until the beam is properly
directed. It is often necessary to raise the front[Pg 139]
or back of the case by shimming between the case and
its platform in order to direct the beam of light the
proper distance ahead of the locomotive.
53. Q. What provision is made for moving or
focussing the lamp in the reflector?
A. When the lamp is mounted horizontally there
are thumb screws by which the lamp may be moved
sidewise, up and down, and forward and backward.
This mounting is called the "micrometer" device, because
of the accuracy of adjustment. With the vertical
mounting, a flat head thumb screw at the base of
the lamp support releases the ball joint so that the
lamp may be easily moved sidewise or forward and
backward. To raise or lower the lamp, the thumb
screw higher on the lamp stand must be loosened.
54. Q. What causes a "black spot" in the illumination
ahead of the locomotive?
A. The lamp is out of focus, being too far ahead
or back of the proper position in the reflector.
55. Q. How would you remedy the following possible
A. (a) All lamps fail to burn. If turbine is not
running the wrong steam valve in the cab may have
been opened, or there may be a second valve, closed,
in the steam pipe. The screen on the governor valve
in the turbine may be clogged. Remove brass cap at
top of turbine and unscrew screen or strainer-cap.
runs, but no lights. Wires
may be "short-circuited" (crossed) which will cause
brushes to spark badly, and turbo-generator to pull
hard. The "short" can usually be found by an occa[Pg 140]sional
sparking or smoke at the point of trouble.
Separate and protect wires when short is found. The
brushes may be "cocked up" as left by some repair
man. Open the dynamo door and see that the brushes
bear on the copper commutator. A wire may be loose
at the dynamo binding posts (which may be seen when
the dynamo door is open), or at the main switch in
the cab. A main wire may have broken. (All locomotives
are not equipped with fuse plugs.) A fuse
plug may have become loose or burnt out. Replace
with new fuse plugs or break an incandescent lamp
and twist the leads in the base together, when the
base may be screwed into the fuse plug socket, answering
the purpose of a fuse plug, temporarily.
(c) Headlight fails to burn. Examine the wires
between cab switch and head lamp for breaks or disconnections.
Examine fuse plugs (which are sometimes
in head lamp circuit only) and proceed as in
(b) if trouble is found there. Headlight bulb may
not be screwed in far enough to make contact in the
socket, as the lock-sockets provided to prevent lamps
loosening cause lamp to screw in hard. Lamp may
have broken fillament. Replace with proper type of
lamp or use a cab lamp.
(d) Lamps burn dim. Steam valve not open wide
enough. Boiler pressure too low. Brushes sparking
badly on commutator of dynamo—due to poor contact.
Governor or steam-valve of turbine improperly
(e) Lamps burn too brightly. Improper turbine
regulation. Throttle the steam valve in cab until
lamps are reduced to proper brilliancy. Report all
irregularities on arriving at terminal.
1. Q. What is the speed of a Schroeder headlight
A. About 2,800 revolutions per minute.
2. Q. How is the speed altered?
A. By a governor in the turbine.
3. Q. How would you proceed to change the speed
of the governor?
A. Remove cover No. 3 and loosen lock nut No.
14 and turn nut No. 13 to the right to increase the
speed and to the left to decrease it.
4. Q. What is a short circuit?
A. A connection between the positive and negative
wires of the dynamo without any resistance
5. Q. How does the dynamo act when short-circuited?
A. It will run very slowly as it is under a heavy
6. Q. What would be the result if left to run
under that strain?
A. The armature or fields would burn out.
7. Q. What would you do if a short circuit developed
while on the road?
A. Shut the steam off and remove the positive or
right-hand wire of the cab circuit from the dynamo,
start up and see if the headlight went to work properly;
if not, replace the cab wire and remove the
positive or left-hand wire and see if the cab lights
burned properly. If such was the case, let it run,
using the small incandescent light in the case for a
headlight and report it at the roundhouse.[Pg 142]
8. Q. What is a volt?
A. The unit of pressure of electricity.
9. Q. What is an ampere?
A. The unit of quantity of electricity.
10. Q. What is the proper voltage of a Schroeder
A. About 28 volts.
11. Q. Can a person be injured by that voltage?
12. Q. What is the proper amperage of a Schroeder
A. About 30.
13. Q. How often should the ball bearings be
A. About three times a week.
14. Q. How often should the governor be oiled?
A. Before leaving every trip.
15. Q. What kind of oil should be used?
A. Valve oil.
16. Q. Is it necessary to clean the electrode every
17. Q. Why?
A. The dynamo is provided with shunt fields
which build up the current regardless of the arc light.
18. Q. What are the two causes of lamp burning
A. Speed too high, or wires to the lamp being
19. Q. If the carbons burned away too fast, but
otherwise the lamp appeared to be burning properly,
where would you look for the trouble?
A. It would indicate that tripping spring No. 209
was too tight.
20. Q. If tripping spring No. 209 was being annealed
from heat and sparks were noticed at the
clutch, where would you look for the trouble?
A. Flexible wire No. 251 would be broken.
"BUDA-ROSS" ELECTRIC HEADLIGHT
1. Q. What are the three essential elements in the
"Buda-Ross" electric headlight equipment?
A. Steam turbine engine, dynamo directly connected
on the same shaft, and self-focusing arc lamp.
2. Q. At what speed should the turbine run?
A. 2,800 revolutions per minute.
3. Q. How is the speed controlled?
A. By a centrifugal governing device.
4. Q. How does the steam enter the turbine?
A. Through a main valve which is perfectly balanced
in all steam pressures directly and impinged on
the buckets directly from a nozzle.
5. Q. About how much opening should this valve
A. About one-fourth of an inch.[Pg 144]
6. Q. Can the lift of this valve be changed?
7. Q. How?
A. By adjusting the inner sleeve of the valve with
a common monkey wrench after removing cap nut
on top of turbine.
8. Q. Can this be done while the light is burning?
9. Q. What is necessary to do this?
A. Take a monkey wrench and screw the inner
sleeve down to the right to reduce the lift, and to the
left to increase the lift. In reducing the lift you reduce
the speed, and by increasing the lift you increase
10. Q. Is there any other method of setting speed?
11. Q. How?
A. By removing oil box on the turbine cap and
adjusting the nuts on the governor studs on the face
12. Q. Is any provision made for operating the
light with low pressure steam?
13. Q. What?
A. An auxiliary valve is used which operates automatically
at any predetermined pressure, which is adjusted
by an adjusting stem at the bottom of the
engine and which can also be adjusted while the light
is burning.[Pg 145]
14. Q. What kind of oil should be used in the
A. Cylinder or valve oil.
15. Q. What style of generator is used.
A. An iron-clad type with no outside magnetism.
16. Q. How many fields in this generator?
17. Q. What style field is used?
A. Compound wound.
18. Q. What kind of wire is used on these fields?
A. Deltabeston wire.
19. Q. Why is Deltabeston wire used in preference
to cotton-covered wire?
A. So that it cannot be injured by short circuits,
for if a short circuit occurs and afterwards is removed
there is no danger done to the insulation on
this make of wire.
20. Q. Where are the fields located?
A. One on each side of the dynamo.
21. Q. Why?
A. So that they cannot be injured by waste oil
from the ball bearing, or by water or snow.
22. Q. How should ball bearing on dynamo end
A. By removing oil plug in frame just back of
dynamo and introducing cylinder oil.[Pg 146]
23. Q. Is it necessary to remove the top carbon
holder from the lamp to remove reflector from case?
24. Q. Why not?
A. Because there is no top guide to the carbon,
as the carbon is guided by the clutches.
25. Q. How many levers are there in the lamp?
A. Only one.
26. Q. What regulation should be given to top
lever spring No. 308 on lamp?
A. Top lever spring No. 308 should be adjusted
as loose as possible and not have light go out standing
27. Q. If this spring was tightened until the light
burned steady when the locomotive was at rest, what
might occur when engine was running high speed?
A. It might cause the light to dim down.
28. Q. Is there anything else that would cause the
light to dim down when the engine is running fast?
A. If the clutches should be used until the sharp
edge that grips the carbon have become worn smooth
or round they would allow the carbon to feed too fast
and the light would burn dim.
29. Q. If the light burns satisfactory while engine
is in motion, but goes out when engine is stopped,
where would you find the trouble?
A. This trouble is most always found to be caused
by the top lever springs No. 308 being too weak; or,
an imperfect carbon, though if the dash pot plunger[Pg 147]
has become corroded until it sticks in the dash pot,
the light will act the same as if the tension spring was
30. Q. Is it possible to apply the bottom electrode
31. Q. Why not?
A. For the reason that its support is on a center
line with the electrode and the holder can be turned
in any direction and the electrode is held central with
the top carbon.
32. Q. What would you do if you had no bottom
A. Place a piece of 5/8-inch carbon in the hole
through the bottom bracket having top end in focal
point of reflector and tighten with set-screw; as this
carbon would burn away the light would be raised
and it would therefore be necessary to raise the carbon
about every hour, as the carbon would burn
away about one-half inch per hour.
GENERAL QUESTIONS AND ANSWERS ON ELECTRIC HEADLIGHTS
33. Q. Describe the passage of the current
through the lamp and tell how arc light is formed?
A. It enters the lamp at the binding posts with the
large hole, then to the top carbon holder, carbon, then
into the electrode and holder; from there to the
solenoid and back to the dynamo, leaving the lamp
at the binding post with the small hole in it. The[Pg 148]
magnetism from the current while passing through
the solenoid attracts magnet in a downward motion,
and it in turn, by the levers on the lamp, separate
the carbon from the copper, thereby forming the arc.
34. Q. Why should sandpaper be used to smooth
commutator instead of emery cloth?
A. In using emery paper a piece of emery might
lodge in the grooves between the commutator segments,
and being a conductor of electricity, causes
short. Will also get embedded in the copper and cut
the brushes. Sand will not do this.
35. Q. State how you would go about to focus
A. (1) Would adjust back of reflector so front
edge of reflector would be parallel with front edge of
case. (2) Adjust lamp to have point of copper electrode
as near the center of reflector as possible with
carbons as near the center of chimney hole as you
can set them. (3) Have the locomotive on straight
track. Now move the base of the lamp around until
you get a parallel beam of white light straight down
the center of the track, then tighten lamp down.
36. Q. If the light throws shadows upon the track,
is it properly focused?
37. Q. If the light is properly focused, that is, if
the rays are leaving the reflector in parallel lines, but
the light does not strike the center of the track, what
should be done?
A. When the light rays are thrown out in parallel
lines and they do not strike the center of the track,[Pg 149]
it denotes that the headlight case is not set straight
with the engine, and the entire case on baseboard
must be shifted until the shaft of light strikes the
track as desired.
38. Q. What can you do to insure a good and
unfailing light for the entire trip?
A. By carefully inspecting the entire equipment
before departing on each trip and know that there
are no wires with insulation chafed or worn off; that
all screws and connections are tight; commutator
clean; brushes set in brush holder in the proper manner;
carbon in lamp of sufficient length to complete
trip; copper electrode cleaned off and oil in both
39. Q. Why would you not fill the main oil cellar
full of oil?
A. If you should fill the main oil cellar full of oil,
the oil would run out of the overflow holes on the
side and all over the equipment and locomotive and
could do the dynamo no good but possibly harm.
40. Q. What is the most vital part of the dynamo?
A. The .
41. Q. What care and attention should be given
A. The commutator must be kept clean, free from
dirt and grease; the mica must be kept filed down
about one-sixty-fourth of an inch below the surface
of the bars.
42. Q. How should you clean the commutator,
A. The commutator should be cleaned before[Pg 150]
starting out on each trip by using a piece of damp
waste, rubbing the bars lengthwise, then wipe dry
with clean dry piece of waste.
43. Q. What kind of a bearing should the brush
have on the commutator?
A. Brushes should be fitted to have a bearing with
the same contour as the commutator, with bearing
covering no less than two of the commutator bars,
nor more than three of the bars.
44. Q. How are the brushes fitted?
A. Brushes are fitted by cutting a strip of No. O
sandpaper about the width of the commutator surface.
(Have the dynamo idle.) Place the strip of sandpaper
under the brush on the commutator with the
rough side towards the brush, then pull the sandpaper
from right to left; continue this process until the
brush has been fitted to a true smooth bearing. Then
trim about one-eighth of an inch off the front edge
of the brush.
45. Q. Is it advisable to ever try to fit a brush up
with a file or knife?
46. Q. Why is it important to clean the scale off
the point of the copper electrode each trip?
A. To allow the point of the carbon and the electrode
to touch to form a circuit; this scale being a
non-conductor of electricity and with it on, the current
would not pass from the carbon to the electrode
47. Q. How should the copper electrode be
trimmed at the point?[Pg 151]
A. Copper electrode should have about ¼-inch
surface at contact point.
48. Q. How far should the copper electrode project
above the holder?
A. One inch.
49. Q. Should the electrode be raised up to 1½
inches, what might happen?
A. If the copper electrode was run at a point so
near the clutch, the intense heat of the arc might do
damage to the top carbon holder and clutch.
50. Q. If the dash pot should be found stuck,
would you put oil in it?
A. Coal oil should be used to clean and cut the
dirt out of the pot and from off the plunger, but after
the dash pot and plunger have been cleaned all oil
should be wiped off of same, as the oil would cause
the plunger to collect dirt and stick.
51. Q. If one carbon of lamp should "jig or
pound", what can be done to stop it?
A. If the carbon jumps or pounds the electrode, it
is evident that the iron armature is too far out of the
solenoid, or the speed is too low.
52. Q. Does the pounding of the lamp occur with
the old series wound machines or with the new compound
A. The pounding of the lamp occurs with the
new compound wound machines.
53. Q. If the copper electrode was fusing, how
would you know it?
A. By the fact, when copper is fused a shaft of[Pg 152]
green light will be thrown off instead of a shaft of
54. Q. What should be done when a green light
A. Close the throttle to turbine engine, then open
slowly until a white light re-appears.
55. Q. What is the cause of the copper electrode
A. The cause of the copper electrode fusing is due
to too high speed of the generator, or having lead
wires connected up wrong, allowing positive current
to get into copper electrode first.
56. Q. What arrangements have been made so
that you cannot connect your wires wrong?
A. The positive binding post both at the dynamo
and lamp have been provided with a much larger
hole to receive the wire than has been made in the
negative binding post, and the ends of the positive
wire should always be bent or doubled back so they
will just enter the receptacle in the positive binding
posts, but cannot be connected to the negative binding
57. Q. Should the copper electrode and holder
become fused until no longer serviceable out on the
road, what would you do?
A. Would remove the damaged holder from the
lamp and substitute a carbon, securing the substituted
electrode in the bracket of lamp same as the electrode
holder is held. Be sure that the end of the carbon
comes up to center of reflector and does not rest on
base of reflector or lamp.[Pg 153]
58. Q. If you were running along with your light
burning steady and nice, then suddenly the light began
to flash badly and kept it up, where would you
look for the trouble?
A. You would no doubt find one of the lead wires
loose in binding post.
59. Q. If you were running along with light burning
satisfactorily and suddenly your light went out,
where would you be likely to find the trouble?
A. You would undoubtedly find carbon burned
out, or a lead wire was broken off or out of the binding
60. Q. If the light goes out while between stations,
what course would an engineer pursue?
A. If investigation cannot be made within a few
minutes thereafter to determine the cause, the steam
should be shut off from the turbine engine until such
time when cause of failure can be determined.
61. Q. Why is it essential to shut off steam and
stop the equipment?
A. If failure was due to a short circuit, damage
might be done to the armature or field coils by overheating.
62. Q. How does the equipment act when short
A. The engine will labor heavily and run slowly
with a large volume of steam blowing at the exhaust,
the carbon points and cab lights will only show a dull
63. Q. How would you test for a broken circuit?
A. Would test for a broken circuit or open circuit:
First, by placing a carbon across the binding posts at[Pg 154]
dynamo. If the trouble was in the dynamo, no flash
would be seen, but if dynamo was all right you would
get a flash; this would indicate that the trouble was
on towards the lamp. Second: Go to the lamp, place
your carbon across binding posts. If wire was broken
between dynamo and lamp you would not get a flash.
If your wires were all right you would get a flash and
you would find your trouble in the lamp. No doubt,
it would be a burned-out carbon.
64. Q. How would you proceed to locate the
point of trouble with a short circuit?
A. Would remove (1) one of the lead wires from
the binding post at dynamo; if trouble was in dynamo
you would not note any difference in action of speed.
(2) Would disconnect one of the cab wires; if the
trouble is in cab circuit, speed would increase and
lamp would burn. (3) If trouble is not in cab circuit,
would go to lamp, disconnect one of the main wires
from binding post; if short circuit is in the wires between
dynamo and lamp, there would be no change
in speed of dynamo, but if the wires are O. K. the
speed of engine would increase and your trouble
would be in the lamp.
1. Q. Of what does the driving mechanism of a
Duplex Locomotive Stoker consist?
A. It consists of a steam cylinder with reverse
head and valve arrangement similar to the steam end
of an eleven inch Westinghouse air pump.
2. Q. How is the power controlled?
A. The speed is variable, and by turning the valve
controlling the engine steam inlet, can be made greater
or less according to the amount of coal needed.[Pg 155]
3. Q. For ordinary operation, how much steam
pressure is required?
A. About fifteen pounds, with piston strokes varying
from 10 to 15 per minute.
4. Q. How can the duplex stoker driving engine
be started, stopped, or reversed?
A. By means of operating and reversing rod,
fastened to the back head and connected with the
valve on reverse head of engine cylinder.
5. Q. How can the conveying screws be started,
stopped, or reversed separately or together?
A. By ratchet and pawl arrangement controlling
6. Q. What practice should be followed in building
up the fire before leaving a terminal?
A. Build up a light even fire by hand and do not
bring stoker into use until the locomotive is working
7. Q. How should the stoker be oiled and operated?
A. It should be thoroughly oiled before leaving
the terminal, then see that operating rod on back head
is in center or running position, open main jet
line so they register about fifteen pounds on the jet
steam gauge if coal is coarse, or ten pounds if coal
is small. Next, the driving engine steam valve should
be opened wide and the throttle valve opened just
enough to supply the proper amount of coal to the
8. Q. How is the distribution of coal over the
grate area accomplished?
A. By means of a low-pressure constant steam jet
located in the back and bottom portion of each distributor
elbow, as indicated by its individual pointer
on steam gauge.
9. Q. By increasing the jet pressure, will more
coal be carried to forward end of fire-box and against
A. Yes, it will, and by decreasing the jet pressure
more coal will be fed at middle and back end of
[Pg 157]10. Q. Can the fireman direct the even distribution
of coal in the fire-box?
A. Yes; by changing position of the dividing rib
located in the transfer hopper, and by moving the
regulating lever to either side.
11. Q. Should the sliding plates at the bottom
of the tank be closed before coal is put on tank?
A. Yes, so that screw conveyor will not become
clogged and inoperative. Only one slide should be
opened at a time and coal fed from tank as required.
12. Q. In case the stoker becomes clogged or it is
desired to reverse it for any reason, what must be
A. The operating rod located on the back-head of
the locomotive boiler—if the piston is making a power
stroke—should be moved to its lower position, and if
the piston is making a return stroke, it should be
moved to its upper position. This moves a small
valve in the auxiliary head, bolted to reverse head,
and steam is admitted to opposite head of cylinder,
causing the piston to change its direction. The return
of the operating rod handle to a central position
causes the driving engine to resume its normal
13. Q. How can the fireman observe the condition
of fire in fire-box?
A. The elbows are provided with peep valves with
swinging covers through which the coal supply and
condition of fire may be seen.
14. Q. Why are two gauges necessary?
[Pg 159]>A. The driving engine gauge on the left indicates
the pressure of steam used by the driving engine.
The one on the right has two indicators, the red indicator
showing the steam pressure on the jet in left
elbow, and the black indicator showing the pressure
on the jet in the right elbow.
15. Q. When train is standing on siding for a
short period, what should be done?
A. Shut stoker off by throwing operating rod on
back head of locomotive boiler out of running position.
16. Q. When train is to stand for a long time or
engine is left at terminal, what should be done?
A. The driving engine should be cut out entirely
by closing main steam line inlet and main lubricator
connection, and in winter time all drain cocks should
17. Q. If sufficient coal can not be supplied over
front grates, what may be the cause?
A. Distributors may be warped and point too low,
or steam jets may be plugged with pipe scale and not
18. Q. How would you start and operate stoker?
A. First open main valve No. 1 at steam turret.
Valve 2 is then opened; this is the main valve in stoker
steam line. Next open valve 3, which allows the
steam to flow to the distributor jet line; open valves
4 and 5, which govern the pressure on the jets until
ten pound pressure shows on the right-hand gauge.
See valve 8 to the exhaust line is open, and valve 9
to the transfer hopper is closed.[Pg 160]
19. Q. How would you start the stoker engine?
A. Place operating lever 10 in horizontal or running
position. Place conveyor reversing lever 12 in
forward position. Open valve 6, which allows the
steam to pass to the operating valve and starts stoker
running. Valve 7 is to be used as an emergency
valve only in case of clogging. Stoker should be run
slowly at first. Do not feed too much coal and carry
a light fire.
20. Q. How would you reverse conveyor screw
A. Lower handle 10 on operation rod on boiler
head to bottom position. Move screw conveyor, reverse
lever 12 back to rear or reverse position, raise
handle 10 on operating rod to center position.
21. Q. How would you stop conveyor screw in
A. Place conveyor reversing lever 12 in center
22. Q. How would you reverse right or left elevator
A. Raise elevator pawl shifter 26 on top of the
vertical shaft to upper position.
23. Q. How would you stop right or left elevator
A. Raise elevator pawl shifter 26 on top of the
elevator to middle position.
24. Q. How would you locate clogs in case the
stoker stalls?[Pg 161]
A. First, shut off pressure to stoker engine cylinder
by closing valve 6. Second, move operating valve
lever 10 to its lowest position. Third, place tender
conveyor reverse lever 12 in center. Fourth, place
right elevator pawl shifter 26 in neutral position.
Fifth, raise operating valve lever 10 to center position.
Sixth, open valve 6 sufficiently to run left elevator to
ascertain if it operates freely. Cut in right elevator
by lowering pawl shifter 26, and if stoker stops, the
obstruction is in the right elevator. If it continues
to operate, then the obstruction is in the tank conveyor.
25. Q. How would you remove clogs?
A. Clogs in upright elevators usually occur at the
bottom. Raise the door in the engine deck and remove
the obstruction if in the elevator, reverse the
elevator screw forcing the obstruction back down in
transfer hopper. It may be a small mine spike lodged
above this point, and by removing the nut at top of
elevator casing and removing the door the obstruction
can be easily removed.
26. Q. If the clog is in the tank conveyor, how
would it be removed?
A. The clog will usually be found in the crushing
zone. Reverse the tank conveyor screw, forcing the
obstruction back, when it can be removed from the
27. Q. How far should the conveyor screw be
A. Not more than three revolutions.
[Pg 163]PARTS OF DUPLEX LOCOMOTIVE STOKER
1. Conveyor Trough.
2. Conveyor Screw.
3. Angle Ring.
5. Operating Head.
6. Driving Engine Cylinder.
7. Reverse Valve.
8. Piston Rod.
9. Transfer Hopper.
10. Left Elevator Casing.
11. Left Elevator Screw.
12. End of Elevator Screw Shaft.
13. Elevator Pawl Shifter.
14. Elevator Pawl Casing.
16. Left Distributor Elbow.
17. Right Distributor Elbow.
18. Dividing Rib.
19. Right Elevator Casing.
20. Oil Box.
21. Conveyor Reverse Lever.
22. Conveyor Oil Cups.
23. Rack Housing.
25. Conveyor Pawl Casing.
26. Conveyor Screw Flexible Connection Sleeve.
27. Conveyor Screw Flexible Connection.
28. Conveyor Slide Support Roller.
29. Conveyor Slide Support.
30. Conveyor End Bearing and Gear Case.
31. Conveyor Screw Gear.
32. Conveyor Screw Driving Gear.
1. Q. When steam is first turned on, what must
it pass through before entering the compressor?
A. The compressor governor.
2. Q. What does Fig. 1 represent?
A. This shows a sectional view of the SF compressor
governor in open position.
3. Q. What is the duty of the compressor governor?
A. To automatically regulate the main reservoir
pressure by controlling the steam to the compressor.
4. Q. How are the regulating portions of the governor
A. The one having two pipe connections and a
light regulating spring is known as the excess pressure
head; the other, with a single pipe connection and
heavy regulating spring, as the maximum pressure
5. Q. When does the excess pressure head control
the flow of steam to the compressor?
A. When the automatic brake valve is in any one
of its first three positions; namely, release, running
and holding positions.
6. Q. With the automatic brake valve in release,
running or holding position, what pressure is in chamber
"f" above the diaphragm? In chamber "d" below
Fig. 1: The SF-4 Compressor Governor.
Connections: FVP, Feed Valve Pipe. ABV, Automatic Brake
Valve. MR, Main Reservoir. B, From Boiler. P, To Air Pump.
A. Air, at feed valve pipe pressure, enters at the
connection marked "FVP" and flows to chamber "f"
above the diaphragm; this pressure acts in conjunction
with the regulating spring 27 in creating the total
pressure on the diaphragm. Air at main reservoir
pressure flows through the automatic brake valve to
the connection marked "ABV" to chamber "d" under
7. Q. At what pressure is the regulating spring in
the excess pressure head adjusted?
A. Usually twenty pounds.
8. Q. With the spring adjusted at twenty pounds,
what will be the total pressure on the upper side of the
A. Twenty pounds, plus the pressure in the feed
9. Q. With the feed valve adjusted at seventy
pounds, and the regulating spring at twenty pounds,
what pressure will be had in the main reservoir when
the governor stops the compressor?
A. Ninety pounds.
10. Q. Explain the operation of the governor in
controlling the compressor when a main reservoir
pressure of ninety pounds is reached.
A. When the main reservoir pressure in chamber
"d" slightly exceeds the pressure on top of the
diaphragm it will move upward, carrying the pin valve
with it. The air in chamber "d" passes by the
unseated pin valve through port "b" into chamber "b"
above the governor piston, forcing it downward, seating
the steam valve 5, thus shutting off the steam to
the compressor.[Pg 167]
11. Q. How long will the governor remain in this
A. Until the main reservoir pressure falls below
ninety pounds, when the combined spring and air
pressure in chamber "f" will force the diaphragm 28
down, seating the pin valve. This shuts off the supply
of air from chamber "d", and the air confined in
chamber "b" will escape to the atmosphere through
the vent port "c". The pressure now being removed
from above the governor piston, the spring 9 aided
by the steam pressure under the valve 5, will force
the piston upward, unseating the steam valve 5,
allowing steam to pass through the governor to the
12. Q. When the steam valve is seated, is steam
entirely shut off from the compressor?
A. No; there is a small port drilled through the
valve; its purpose is to maintain a circulation in the
steam pipe and keep the compressor working slowly;
thereby preventing condensation when the steam valve
13. Q. With the automatic brake valve in release,
running, or holding position, does the maximum pressure
A. No; as during this time the main reservoir pressure
is not sufficiently high to actuate its diaphragm.
14. Q. Where does the air come from that operates
the maximum pressure head?
A. From the main reservoir direct. (See Fig. 1.)
15. Q. When does the maximum pressure head
control the compressor?[Pg 168]
A. When the automatic brake valve is in either
lap, service or emergency position, also when the
main reservoir cut-out cock is closed.
16. Q. How is the pressure created on top of the
diaphragm in the maximum pressure head?
A. By the regulating spring 19.
17. Q. What is the adjustment of this spring?
A. Spring 19 is adjusted to the maximum pressure
desired in the main reservoir usually 130 pounds.
18. Q. Explain the operation of the governor
when the main reservoir pressure exceeds the tension
of the regulating spring 19.
A. When the pressure in chamber "a" exceeds
the tension of the regulating spring 19, the diaphragm
20 is forced upward, unseating the pin valve,
allowing air to flow from chamber "a" to chamber
"b" above the governor piston, forcing it down, shutting
off steam and stopping the compressor.
19. Q. How long will the governor remain in this
A. Until the main reservoir pressure in chamber
"a" under the diaphragm becomes slightly less than
the adjustment of the regulating spring 19, when the
diaphragm 20 will move down, seating the pin valve,
shutting off the flow of air from chamber "a" to
chamber "b". The air entrapped above the governor
piston will escape to the atmosphere through the relief
port "c"; this will allow the governor piston to raise,
unseating the steam valve 5, again allowing steam to
pass through the governor to the compressor.
20. Q. Is the maximum pressure head cut out in
any position of the automatic brake valve?[Pg 169]
A. No; as the air that operates this head comes
direct from the main reservoir, therefore is not controlled
by the brake valve.
21. Q. Is the excess pressure head cut out in any
position of the brake valve?
A. Yes; as the air that operates this head comes
through the automatic brake valve, and when the
handle is moved beyond holding position, the port in
the rotary valve seat, through which the air flows to
chamber "d" is closed, thereby cutting out this head,
leaving the compressor under the control of the maximum
22. Q. What is the object of the duplex or double
A. By use of the duplex governor the main
reservoir pressure may be controlled at two different
predetermined pressures; as when running along the
excess or low pressure head controls the compressor,
at the low pressure—usually ninety pounds—this being
sufficient to keep the brakes released and fully
charged; whereas, in lap position, as following a
brake application, the maximum or high pressure head
controls the compressor at the maximum pressure used—generally
130 pounds—this for a prompt release
and quick recharge of the brakes. From this it will
be seen that the compressor has to work against the
high pressure only during the time the brake is applied.
23. Q. In what position should the automatic
brake valve handle be placed when adjusting the excess
pressure head? The maximum pressure head?
A. Running position for the excess pressure head;
lap position for the maximum pressure head.
24. Q. If, with the automatic brake valve handle
in running position, the brake pipe and main reservoir[Pg 170]
do not stand twenty pounds apart, where would you
look for the trouble?
A. Would first learn if the maximum pressure
head was properly adjusted, and if it were, would then
look for the trouble in the adjustment of the regulating
spring in the excess pressure head.
25. Q. What should be done?
A. The regulating spring should be properly adjusted.
26. Q. How should the adjustment of the regulating
spring in either pressure head be made?
A. By removing the cap nut 25 or 17 and screwing
the regulating nut 26 or 18 up or down as may
DEFECTS OF THE GOVERNOR
27. Q. What would be the effect if one or both
of the pin valves leaked?
A. Would cause a delay in opening of the steam
valve after the pin valve had seated; and if air leaks
by faster than it can escape through the relief port
"c", pressure will accumulate in chamber "b" and
force the governor piston downward, so as to partially
or wholly close the steam valve 5.
28. Q. How can you tell if the pin valves leak?
A. Leakage past the pin valve in the maximum
pressure head will cause a constant blow at the relief
port in all positions of the brake valve; leakage past
the pin valve in the excess pressure head will cause a
blow in the first three positions of the brake valve
29. Q. What would be the effect if the relief
port "c" stopped up?[Pg 171]
A. The compressor will not start promptly after
the pin valve seats.
30. Q. What would be the effect if the drain
port "W" were stopped up?
A. Steam leaking into the chamber under the
governor piston will form a pressure and prevent the
piston being forced downward to close the steam
valve; the compressor will therefore continue to work
until the main reservoir pressure is about equal to
31. Q. If the pipe leading from the feed valve
pipe to the excess pressure head of the governor
breaks, what effect will it have on the compressor?
A. The compressor will stop when the main reservoir
pressure reaches about forty-five pounds.
32. Q. If the pipe breaks, what should be done?
A. Plug the end toward the feed valve and put a
blind gasket in the pipe leading from the automatic
brake valve to the governor, at the connection
33. Q. If the pipe leading from the automatic
brake valve to the governor breaks, what should be
A. Plug the pipe toward the brake valve; the
compressor will now be controlled by the maximum
34. Q. If the pipe leading from the main reservoir
to the maximum head of the governor breaks,
what should be done?
A. Plug the main reservoir end of the pipe. The
excess pressure head will now control the compressor
in the first three positions of the automatic brake
valve handle, but will have no control after the handle
is moved as far as lap position.[Pg 172]
35. Q. What is the purpose of the parasite governor,
and where is this governor located?
A. This governor is located in the pipe connection
between the main reservoir and parasite reservoir, and
its purpose is to control the flow of air from the main
to the parasite reservoir.
36. Q. What is the purpose of the parasite reservoir?
A. It is here that air is stored for use in all air
operated devices on the locomotive, except the brake.
37. Q. Explain the operation of the parasite
A. The operation of this governor is much the
same as the compressor governor, and differs only in
that the supply valve is open when it is in its lower
38. Q. At what pressure is the regulating spring
A. About fifteen pounds.
39. Q. What pressure is required in the main
reservoir before air is admitted to the parasite reservoir?
A. At least fifteen pounds above that in the brake
40. Q. What pressure is obtained in the parasite
A. The same as that in the main reservoir, when
the main reservoir pressure is fifteen pounds greater
than that in the brake pipe.
41. Q. What will prevent the charging of the
parasite reservoir, and what should be done?[Pg 173]
A. This may be caused by the feed valve being
improperly adjusted, sticking in open position or leakage
of main reservoir air past the valve to the feed
valve pipe and governor top.
WESTINGHOUSE 9½ OR 11-INCH COMPRESSOR
42. Q. What is the duty of the air compressor?
A. To furnish the compressed air used in the
operation of the brakes, and all other air operated
appliances on both locomotive and cars.
43. Q. Explain the operation of the steam end of
A. When steam is turned on at the boiler it flows
through the steam pipe and governor, entering the
compressor at the steam enlet, then through the steam
passage "a" to the reversing valve chamber "C" also
to the main valve chamber "A" between the differential
pistons 77 and 79. The area of the piston at
the right being greater than the one at the left, the
main valve is moved to the right, (See Fig. 2) admitting
steam to port "b" which leads to the lower
end of the steam cylinder; steam is now free to flow
under the main piston, forcing it upward. When the
piston has almost completed its upward stroke, the
reversing plate 69 on top of the piston 65 engages a
shoulder on the reversing rod 71, moving the rod and
reversing valve 72 upward (See Fig. 3). The upward
movement of the reversing valve closes the
ports "f" and "h" and opens port "g"; thus permitting
steam to enter the chamber at the right of the
large piston 77, balancing the pressure on this piston,
and the pressure acting on the right side of the small
piston 79—the chamber at the left being open to the
exhaust—will force the main valve to the left.
Fig. 2: Diagrammatic View, Up Stroke.
When the main valve moves to the left, steam is admitted
through port "c" to the upper end of the cylinder on
top of the piston 65, forcing it downward. At the
same time the lower end of the cylinder is connected
through exhaust cavity "b" of the main valve to the
exhaust port "d", allowing the steam below the piston
to escape to the atmosphere.
44. Q. When the piston has about completed its
downward stroke, what takes place?
A. The reversing plate 69 engages the button "k"
on the end of the reversing rod 71 pulling the rod
and the reversing valve down. This movement of the
reversing valve closes port "g" and the cavity in the
face of the valve connects ports "f" and "h", which
allows the steam in chamber "D" at the right of the
large differential piston to escape to the exhaust, thus
allowing the main valve to move to the right, exhausting
the steam from the top end of the cylinder, and
at the same time admitting steam to the lower end,
causing an upward stroke of the piston.
45. Q. Explain the operation of the air end of
A. The movement of the steam piston 65 is imparted
to the air piston 66 by means of the piston
rod. When the air piston moves up, a partial vacuum
is formed below it, and air from the atmosphere will
enter through passage "F" thence through passage
"n" to the under side of receiving valve 86b (see
Fig. 2), lifting this valve from its seat, and will fill
the cylinder with air at about atmosphere pressure.
Fig. 3: Diagrammatic View, Down Stroke.
In the meantime the air above the piston, being
compressed, will hold the upper receiving valve 86a
to its seat, and when the pressure is slightly greater
than that in the main reservoir, this pressure acting
under the upper discharge valve 86c, will lift this valve
from its seat and now the air will be free to flow
through passage "G" to the main reservoir connection.
On the down stroke the action is similar, air is taken
in through the upper receiving valve 86a, while the
air below the piston is being compressed and forced
past the lower discharge valve 86d, to the main
reservoir. (See Fig. 3.)
46. Q. What lift should the air valves have?
A. All valves should have a lift of three thirty-second
of an inch.
47. Q. At what speed should the compressor be
run to obtain the best results?
A. At 100 to 120 single strokes per minute.
48. Q. What kind of oil should be used in the
air end of the compressor and on the swab?
A. Valve oil.
49. Q. How often should the air end of the compressor
A. No fixed rule can be given as so much depends
on the condition of the compressor, as well as
the amount of work required; but in any case it
should be used sparingly.
50. Q. What do Figures 4 and 5 represent?
A. These are diagramatic views of a cross-compound
51. Q. Why is this called a cross-compound compressor?
Fig. 4: Diagram of 8½" Cross-Compound Compressor.
High Pressure Steam (Low Pressure Air) Piston on Its Upward Stroke
A. Because both steam and air are compounded,
that is, the steam is used the second time before it is
exhausted to the atmosphere, while the air is com[Pg 179]pressed
the second time before it is delivered to the
52. Q. How many cylinders have the cross-compound
A. Four; two steam cylinders and two air
53. Q. What is the diameter of the different
A. The high pressure steam cylinder is 8½
inches; the low pressure steam cylinder 14½ inches;
the low pressure air cylinder 14½ inches; high pressure
air cylinder 9 inches.
54. Q. Explain the valve gear of this compressor.
A. The valve gear is the same as that of the 9½
or 11 inch compressor, only that a piston valve is used
to distribute the steam instead of a slide valve.
55. Q. Where does the steam come from that is
used in the high pressure steam cylinder?
A. Direct from the boiler.
56. Q. Where does the steam come from that is
used in the low pressure steam cylinder?
A. The steam after doing work in the high pressure
steam cylinder is exhausted into the low pressure
steam cylinder, where it becomes the working pressure
of this cylinder.
57. Q. Explain the operation of this compressor.
A. When steam is first turned on, it enters the
compressor at the steam inlet (see Fig. 4) and flows
through passage "a" into the reversing valve chamber[Pg 180]
"C" and on to chambers "b" and "y" against the
inner faces of the differential pistons, causing the
main valve to move to the right. In this position of
the main valve, port "g" is open to chamber "b",
thus admitting live steam to the lower end of the high
pressure steam cylinder, causing an upward movement
of the piston 7. When the piston 7 has nearly
completed its up stroke, the reversing plate 18, which
is attached to the top of this piston, comes in contact
with a shoulder on the reversing rod 21, forcing it
upward, carrying with it the reversing valve 22, the
movement of which closes port "m", at the same time
opens port "n", filling chamber "D" with live steam
from chamber "C" and passage "a". This balances
the pressure on the two sides of the large piston of
the differential pistons, and the pressure acting against
the inner side of the small piston causes the main valve
to move to the left (see Fig. 5). The main valve
moving to the left closes port "g" to the live steam
and at the same time connects this port with port "f"
leading to the lower end of the low pressure steam
cylinder, causing an up stroke of the low pressure
steam piston 8. In the meantime port "c", which
leads to the upper end of the high pressure steam
cylinder, is open to chamber "y", allowing live steam
to flow down on top of the high pressure steam piston
7, forcing it downward. As the high pressure steam
piston about completes its downward stroke, the reversing
plate 18 engages the button on the lower end
of the reversing rod 21, pulling the rod and reversing
valve 22 down, closing port "n" and at the same time
connecting port "m" and "l" through the exhaust
cavity "q", thus allowing the steam in chamber "D"
to escape to the exhaust. The pressure being removed
from the outer face of the large differential
piston, the main valve will again move to the right,[Pg 181]
opening port "g", admitting live steam beneath the
piston 7, and at the same time connecting the upper
end of the high pressure steam cylinder through port
"c", chamber "h" and port "d" to the upper end of
the low pressure steam cylinder, causing a downward
movement of the low pressure steam piston; the steam
below this piston will now be free to escape to the
exhaust through port "f", chamber "i" and port "e".
Thus it will be seen that the steam used in the high
pressure steam cylinder is live steam from the boiler,
while the steam used in the low pressure steam cylinder
is the exhaust steam from the high pressure steam
58. Q. Explain the operation of the air end of
A. As the low pressure air piston 9 moves up, a
partial vacuum is created beneath it and air from
the atmosphere enters the air inlet and passage "r"
past the lower receiving valve 38 and fills the lower
end of the cylinder with air at about atmospheric
pressure (see Fig. 4). In the meantime the air above
the piston being compressed will hold the upper receiving
valve 37 to its seat, thus preventing a back-flow
of air to the atmosphere; at the same time the
upper intermediate discharge valves 39 are forced
from their seats, allowing the air from the low pressure
air cylinder to flow through passage "u" to the high
pressure air cylinder, the piston of which is now moving
downward. The air beneath the high pressure
air piston 10 being compressed will hold the lower
intermediate discharge valves 40 to their seats, thus
preventing the air in the high pressure air cylinder
flowing back to the low pressure air cylinder. When
the pressure in the high pressure air cylinder becomes
slightly greater than the main reservoir pressure, the[Pg 182]
final discharge valve 42 will be forced from its seat
and the air beneath the piston allowed to flow to the
main reservoir through passage "w". On the opposite strokes
of these pistons air is compressed in a similar
manner, but the opposite air valves are used.
Fig. 5: Diagram of 8½" Cross-Compound Compressor.
The High Pressure Steam (Low Pressure Air) Piston on Its Downward Stroke
59. Q. How many valves are there in the air end
of the compressor?
A. Ten; two upper and two lower receiving valves;
two upper and two lower intermediate discharge
valves; one upper and one lower final discharge
60. Q. Are the air valves all the same size?
A. No; the receiving and final discharge valves
are the same size and of the size used in the 11-inch
compressor, while the intermediate valves are the
same as used in the 9½-inch compressor. The receiving
and final discharge valves are two inches in
diameter, while the intermediate valves are one and
61. Q. What lift is given the different air valves?
A. All valves have 3/32-inch lift.
DEFECTS OF THE COMPRESSOR
62. Q. What are some of the common causes for
the compressor stopping?
A. Lack of lubrication; bent, worn or broken
reversing rod; loose or worn reversing plate; nuts on
air end of piston rod coming off; defective compressor
governor; and, in addition with the cross-compound
compressor, final discharge valve broken or stuck
open, or packing rings in main valve pistons breaking
and catching in the steam ports.
63. Q. What will cause the piston to make an
uneven stroke?[Pg 184]
A. This may be caused by a broken or stuck open
air valve, or air valves not having proper lift. Where
the piston short strokes, it is generally caused by over-lubrication
of the steam end.
64. Q. What are some of the common causes for
the compressor running hot?
A. The overheating of the compressor may be due
to any one of the following causes: Running at high
speed; working against high pressure; packing rings
in air piston badly worn; air cylinder worn; defective
air valves; air passages or air discharge pipe partially
stopped up; leaky piston rod packing; lack of lubrication.
65. Q. What will cause the compressor to run slow?
A. This may be caused by leaky air piston
packing rings; final discharge valves leaking, or air
passages partially stopped up. A defective governor
may also cause the compressor to run slow.
66. Q. What will cause the compressor to run
very fast and heat, and not compress any air?
A. This may be caused by the strainer becoming
clogged with ice or dirt, preventing air entering the
67. Q. If, when steam is first turned on, the piston
makes a stroke up and stops, where would you look
for the trouble?
A. The shoulder on the reversing rod may be
worn; the opening in the reversing plate too large to
engage the shoulder on the reversing rod; loose reversing
plate studs preventing the piston traveling far
enough to reverse the compressor, or the main valve
stuck in its position at the right.[Pg 185]
68. Q. If the piston makes a stroke up and a
stroke down and stops, where is the trouble?
A. This may be caused by a loose reversing plate,
or the button on the lower end of the reversing rod
worn or broken off, or the nuts off the piston rod in
the air end, or the main valve stuck in its position at
69. Q. What will cause the piston to make a quick
A. This may be caused by a broken or stuck open
upper receiving or lower discharge valve.
70. Q. What will cause the piston to make a quick
A. Lower receiving or upper discharge valve
broken or stuck open.
71. Q. If a receiving valve breaks or sticks open,
how may it be located?
A. The air will flow back to the atmosphere as
the piston moves toward the defective valve and may
be detected by holding the hand over the strainer.
72. Q. If a receiving valve in a cross-compound
compressor breaks, what may be done?
A. Remove the broken valve, blocking the opening
made by its removal, and as there are two upper
and two lower receiving valves the compressor will
now take air through the other valve.
73. Q. If an intermediate discharge valve breaks
or sticks open, how may it be located?
A. No air will be taken in to that end of the compressor
as the piston moves from the defective valve,
and may be located by holding the hand over the
74. Q. If an intermediate discharge valve breaks,
what may be done?
A. Remove the broken valve, blocking the opening
made by its removal, and as there are two upper
and two lower intermediate discharge valves the air
will now pass from the low pressure cylinder to the
high pressure cylinder through the other valve.
75. Q. If a final discharge valve breaks, what
effect will it have on the compressor?
A. Will cause the compressor to stop when the
main reservoir pressure is in excess of forty pounds.
76. Q. How would you test for a defective final
A. To test for this defect, bleed the main reservoir
pressure below forty pounds, and if the compressor
starts it indicates a defective discharge valve.
77. Q. If a final discharge valve breaks, what
may be done?
A. As the receiving valves and final discharge
valves are the same size, the defective valve may be
replaced by one of the receiving valves, blocking the
opening made by the removal of the receiving valve.
78. Q. Where piston rod packing is blowing bad,
what may be done to stop it?
A. This generally indicates lack of lubrication,
and by cleaning and oiling the swab the trouble may
be overcome. However, there are times when leakage
by the packing is so great that the oil is blown off the
swab as fast as it is applied, therefore is of no value
in lubricating the parts. Where this condition exists,
a little hard grease wrapped up in an old flag and tied
around the piston rod will ensure its being lubricated.[Pg 187]
79. Q. If the compressor stops, how can you tell
if the governor is responsible for the trouble?
A. By opening the drain cock in the steam passage
between the governor and the compressor; if steam
flows freely, the trouble is in the compressor; if not,
it is in the governor.
80. Q. How may a compressor often be started
when it stops?
A. By closing the steam throttle for a few seconds,
then opening it quickly; if this does not start it, try
tapping the main valve chamber. This will usually
overcome the trouble where the compressor stops on
account of lack of lubrication.
81. Q. What will cause a compressor to short-stroke
A. Too much oil in the steam end; bent reversing
rod; or low steam pressure, as when the governor has
almost shut off the steam.
ENGINEER'S BRAKE VALVE
82. Q. Name the different positions of the G-6
and H-6 brake valves.
A. Release, running, lap, service, and emergency
position, with the G-6; release, running, holding, lap,
service, and emergency positions, with the H-6.
83. Q. What is the purpose of release position?
A. To provide a large and direct opening from
the main reservoir to the brake pipe, for the free flow
of air, when charging and recharging the brakes.
84. Q. What pressure will be had in the brake
pipe if the brake valve be left in release position?
A. Main reservoir pressure.[Pg 188]
85. Q. Can the locomotive brake be released by
the automatic brake valve in release position, when
using the H-6 valve?
A. No; as the port in the automatic brake valve
to which the distributing valve release pipe is attached
is blanked in this position of the valve.
86. Q. What is the purpose of running position,
and when should it be used?
A. This is the proper position for the brake valve
when the brakes are charged and not in use, also
when it is desired to release the locomotive brake with
this valve. In this position the brake pipe pressure
is maintained at a predetermined amount by the feed
valve, as all air that now enters the brake pipe must
pass through the feed valve.
87. Q. What is the purpose of holding position?
A. To hold the locomotive brake applied while
recharging the brakes. The charging of the brake
pipe and equalizing reservoir is the same in holding
as in running position.
88. Q. What is the purpose of lap position?
A. To hold both the locomotive and train brakes
applied after an automatic application.
89. Q. What is the purpose of service position?
A. This position of the brake valve enables the
engineer to make a gradual reduction of brake pipe
pressure, thus causing a service application of the
90. Q. What is the purpose of emergency position?
A. In this position of the brake valve, the brake
pipe is connected directly with the atmosphere through[Pg 189]
the large ports in the valve, causing a sudden reduction
of brake pipe pressure, this in turn causing the
distributing valve on the engine and all operating
triple valves on cars in the train to move to emergency
position, thus insuring a quick and full application of
91. Q. How should the brake valve be handled
when making an emergency application of the brake?
A. The valve should be placed in full emergency
position and left there until the train stops, even
though the danger may have disappeared.
DEFECTS OF THE BRAKE VALVE
92. Q. What will cause a constant blow at the
brake pipe exhaust port, and what may be done to
A. This indicates that the brake pipe exhaust
valve is being held off its seat, due no doubt to dirt;
tapping the side of the valve will sometimes stop the
blow; if not, close the brake pipe cut-out cock and
make a heavy service reduction; next, place the brake
valve handle in release position. This will cause a
strong blow at the exhaust port, which will invariably
remove the trouble.
93. Q. If the pipe connecting the brake valve
with the equalizing reservoir breaks, can both locomotive
and train brakes be operated with the automatic
A. Yes; by placing a blind gasket in the pipe
connection at the brake valve and plugging the brake
pipe exhaust port. To apply the brake, move the
handle carefully toward emergency position, making
a gradual reduction of brake pipe pressure through[Pg 190]
the direct exhaust ports of the brake valve; when the
desired reduction is made, the handle should be moved
gradually back to lap position.
94. Q. What would be the effect if the handle
were moved to lap quickly?
A. Would cause the release of the brakes on the
head end of the train.
95. Q. What will cause air to blow at the brake
pipe exhaust port when the handle is moved to lap
A. This is caused by a leak from the equalizing
reservoir or its connections, which reduces the pressure
in chamber "D" above the equalizing piston,
allowing brake pipe pressure under the piston to force
it up, unseating the brake pipe exhaust valve, permitting
brake pipe air to flow to the atmosphere.
96. Q. What is the purpose of the equalizing
A. The purpose of the equalizing reservoir is to
furnish a larger volume of air above the equalizing
piston than is found in chamber "D", thus to enable
the engineer to make a graduated reduction of the
pressure above the equalizing piston.
97. Q. What defect will cause the brake pipe and
main reservoir pressure to equalize when the handle
is in running position?
A. This may be caused by leakage past the rotary
valve, defective body gasket, or leakage by the feed
valve or its case gasket. To determine which part is
at fault, close the cut-out cock under the brake valve[Pg 191]
and move the handle to service position, exhausting
all air from chamber "D" and the brake pipe; return
the handle to lap position. Leakage of air past the
rotary valve is generally into the brake pipe port
which allows the air to come in under the equalizing
piston, thus forcing it upward, unseating the brake
pipe exhaust valve, allowing this air to escape to the
atmosphere at the brake pipe exhaust port. Leakage
past the body gasket allows air to enter chamber "D",
above the equalizing piston, holding it in its lower
position, keeping the brake pipe exhaust port closed,
thereby preventing the escape of this air to the atmosphere.
Since the capacity of the equalizing reservoir
and chamber "D" is small, such a leak will cause
the black hand to quickly move up to the position of
the red hand. To determine if the leakage be in the
feed valve or its gasket, recharge the brake pipe to
some pressure below the adjustment of the feed valve,
then place the handle in lap position. If the black
hand on the air gauge remains stationary, it is fair
to assume that the trouble is in the feed valve or its
gasket, as in this position of the brake valve the feed
valve is cut out.
98. Q. With the engine alone, the brake pipe
pressure will equalize with that in the main reservoir,
while when coupled to a train the pressure will remain
at that for which the feed valve is adjusted; where
is the trouble?
A. This is caused by light leakage of main reservoir
air into the brake pipe, and may come past the
rotary valve, body gasket, or feed valve, and with the
lone engine is sufficient to raise the brake pipe pressure
to that in the main reservoir; while, when coupled to
a train, the brake pipe leakage of which is greater
than this amount, this leakage will not be noticed.[Pg 192]
THE FEED VALVE AND ITS DEFECTS
99. Q. What do Figures 6 and 7 represent?
A. These are diagrams of the B-6 feed valve in
both open and closed positions.
100. Q. Name the different parts of the feed valve.
A. The valve consists of the following parts: 2,
valve body; 3, pipe bracket; 5, cap nut; 6, piston
spring; 7, piston spring tip; 8, supply valve piston;
9, supply valve; 10, supply valve spring; 11, regulating
valve cap nut; 12, regulating valve; 13, regulating
valve spring; 14, diaphragm; 15, diaphragm
ring; 16, diaphragm spindle; 17, regulating spring;
18, spring box; 19 and 20, stop rings; 21, clamping
screw; 22, hand wheel.
101. Q. Explain the operation of the feed valve.
A. The feed valve consists of two portions, the
supply and regulating portions. The supply portion
consists of a slide valve 9 and a piston 8 (see Fig. 6).
The supply valve 9 opens and closes communication
between the main reservoir and the feed valve pipe
and is moved by the piston 8 which is operated by
main reservoir air entering through passage "a" on
one side or by the pressure of the spring 6 on the
other side. The regulating portion consists of a brass
diaphragm 14, on one side of which is the diaphragm
spindle 16, held against the diaphragm by the regulating
spring 17, and on the other side a regulating
valve 12, held against the diaphragm or its seat, as
the case may be, by the spring 13. Chamber "L" at
the left of the diaphragm is open to the feed valve
pipe through the passage "e" and "d". The feed
valve is adjusted by turning the hand wheel 22 in or
out, thus increasing or decreasing the pressure exerted
by the spring on the diaphragm. The same results[Pg 193]
are obtained in turning the hand wheel 22 as when
turning the adjusting screw in the older types of feed
Fig 6: Diagram of B-6 Feed Valve, Closed.
Connections: MR, Main Reservoir Pipe; FVP, Feed Valve Pipe.
Air from the main reservoir flowing through
passage "a" into chamber "B" will force the piston 8
to the left against the tension of the spring 6; the
piston in moving will take with it the supply valve 9,
opening the supply port in the valve to port "c" in
its seat as shown in Fig. 7. Main reservoir air will
now be free to flow through passage "a", chamber
"B", port "c" and passage "d" to the feed valve pipe.
Air coming through port "c" also flows through passage
"e" to chamber "L" at the left of the diaphragm
14, and this pressure tends toward forcing the diaphragm
to the right; but the diaphragm being supported
by the regulating spring 17, will remain in its
position at the left, holding the regulating valve 12
off its seat, until the pressure in chamber "L" exceeds
the tension of the regulating spring 17. Air, therefore,
continues to flow from the main reservoir through
a, B, c, d and e to the feed valve pipe and chamber
"L", increasing the pressure, until the pressure on the
diaphragm 14 overcomes the tension of the regulating
spring 17, when the diaphragm will move to the right,
allowing the spring 13 to force the regulating valve 12
to its seat, closing port "K". Chambers "G" and
"H" are then no longer open to chamber "L" and the
feed valve pipe, and these chambers being small, the
pressure raises quickly to main reservoir pressure due
to the leakage of air past the supply piston 8, which
forms but a loose fit in its bushing. When the pressure
in chamber "G" becomes nearly equal to that in chamber
"B", the piston spring "6" forces the piston 8 and
its slide valve 9 to closed position, which prevents
further flow of air from the main reservoir to the feed
valve pipe (see Fig. 6). The feed valve will remain
in closed position until the pressure in chamber "L"
is slightly reduced so that the pressure on the diaphragm
14 is no longer able to withstand the pressure
of the regulating spring 17, which then forces the[Pg 195]
diaphragm to the left, lifting the regulating valve 12
from its seat and again opening port "K" to chamber
"L", thus dropping the pressure at the left of piston 8
below that of the main reservoir acting on the opposite
side of the piston.
Fig. 7: Diagram of B-6 Feed Valve, Open.
Main reservoir pressure then
forces the supply piston and valve over into open
position, as shown in Fig. 7, and allows a further flow
of air through port "c" to the feed valve pipe to again
raise its pressure to the adjustment of the feed valve,
when the valve will again close.
102. Q. What is the duty of the feed valve?
A. To control and maintain a constant pressure
in the brake pipe when the brake valve is in running
or holding position.
103. Q. What defect in the feed valve will cause
the brake pipe pressure to equalize with that in the
A. This may be caused by a defective feed valve
case gasket, permitting main reservoir air to leak into
the feed valve pipe, or leakage past the supply valve,
or the regulating valve held from its seat, or the
supply valve piston too tight a fit in its cylinder.
104. Q. If the brake pipe charges too slowly when
nearing the maximum pressure, where is the trouble?
A. This may be caused by a loose-fitting supply
valve piston 8, or the port past the regulating valve
12 partly stopped up.
105. Q. How should the feed valve be tested?
A. With the brakes released, and charged to the
adjustment of the feed valve, create a brake pipe
leak of from seven to ten pounds and note the black
hand on the brake pipe gauge. The fluctuation of
this hand will indicate the opening and closing of the
feed valve, which should not permit a variation of
over two pounds in brake pipe pressure; if it does,
it indicates a dirty condition of the valve, and should
be cleaned.[Pg 197]
106. Q. If the main reservoir pipe connection to
the feed valve breaks, what should be done?
A. This will cause a loss of main reservoir air, and
both ends of the pipe must be plugged. As no air
now comes to the feed valve to charge the brake pipe
in running or holding position of the brake valve, the
handle must be carried in release position.
107. Q. What must be done if the pipe between
the feed valve and automatic brake valve breaks?
A. Slack off on the regulating nut of the feed
valve until all tension is removed from the regulating
spring and plug the pipe toward the brake valve. To
charge the brake pipe, the brake valve handle must
be carried in release position.
108. Q. If the feed valve becomes defective so
that it will not control brake pipe pressure, what
may be done?
A. As the reducing valve used for the independent
brake, and the feed valve are practically the same,
they may be changed one for the other, the reducing
valve taking the place of the feed valve.
INDEPENDENT BRAKE VALVE
109. Q. Name the different positions of the independent
brake valve used with the E-T equipment.
A. Release, running, lap, slow-application position,
110. Q. What is the purpose of release position?
A. To release the locomotive brake when the automatic
brake valve is in other than running position.
111. Q. What is the purpose of running position?[Pg 198]
A. This is the proper position for the brake valve
when not in use, and to release the locomotive brake
when the automatic brake valve is in running position.
112. Q. What is the purpose of lap position?
A. To hold the locomotive brake applied after
an independent application.
113. Q. What is the purpose of slow-application
A. This position may be used when it is desired
to make a light or gradual application of the brake,
as in stretching or bunching the slack of a train.
114. Q. What is the purpose of quick-application
A. To apply the locomotive brake quickly, as in
115. Q. What brake cylinder pressure is usually
developed with this brake?
A. About forty-five pounds.
DEAD ENGINE FEATURE
116. Q. What is the dead engine device?
A. The dead engine device is a pipe connection
between the main reservoir and the brake pipe. In
this pipe is found a combined strainer and check
valve with a choke fitting and cut-out cock, which
when open forms a connection between the brake
pipe and the main reservoir.
117. Q. What is the purpose of this device?
A. To provide a means of charging the main
reservoir of an engine whose compressor is inoperative.[Pg 199]
118. Q. What is the object of charging a main
reservoir of an engine with a disabled compressor?
A. As the air used in the locomotive brake cylinders
comes from the main reservoir, for the brakes
to be operated on this engine it is necessary that its
main reservoir be charged.
119. Q. With a 70-pound brake pipe pressure,
what pressure should be had in the main reservoir
when using this device?
A. About fifty pounds.
120. Q. When the dead engine feature is being
used, in what position should the automatic and independent
brake valves be carried?
A. Running position.
121. Q. What should be the position of the brake
pipe cut-out cock below the brake valve?
A. It should be closed.
122. Q. What is the duty of the distributing valve?
A. To admit air from the main reservoir to the
locomotive brake cylinders when applying the brake,
to automatically maintain the brake cylinder pressure
against leakage, to develop the proper brake cylinder
pressure regardless of piston travel and to exhaust the
air from the brake cylinders when releasing the brake.
123. Q. To what is the distributing valve attached?
A. To the distributing valve reservoir.
124. Q. How many chambers has the distributing
valve reservoir?[Pg 200]
A. Two; pressure chamber and application chamber.
Fig. 8: Release, Automatic or Independent.
Connections: MR, Main Reservoir Pipe; IV, Distributing Valve Release Pipe;
II, Application Cylinder Pipe; CYLS, Brake Cylinder Pipe; BP, Brake Pipe.
125. Q. Name the different pipe connections to
the distributing valve reservoir.
A. Referring to Fig. 8, the connection marked
"MR" is the main reservoir supply pipe; "II", application
cylinder pipe; "IV", distributing valve release
pipe; "BP", brake pipe; "CYLS", brake cylinder pipe.
126. Q. To what do these different pipes connect?
A. The main reservoir supply pipe connects the
distributing valve with the main reservoir pipe. The
application cylinder pipe connects the application
cylinder of the distributing valve with the independent
and automatic brake valves. The distributing valve
release pipe connects the application cylinder exhaust
port in the distributing valve with the independent
brake valve, and through it, when in running position,
to the automatic brake valve. The brake cylinder
pipe connects the distributing valve with the different
brake cylinders on the locomotive. The brake pipe
branch pipe connects the distributing valve with the
127. Q. Explain the operation of the distributing
valve when making an automatic service application
of the brake.
A. When the brakes are fully charged, the brake
pipe and pressure chamber pressures are equal, and
when a gradual reduction of brake pipe pressure is
made it will be felt in chamber "p" at the right of
the equalizing piston 26, creating a difference in pressure
on the two sides of the piston, causing it to move
to the right. The first movement of the piston closes
the feed groove "v", also moves the graduating valve
28, uncovering the service port "z" in the equalizing
slide valve 31; this movement of the piston also
causes the shoulder on the end of its stem to engage[Pg 202]
the equalizing slide valve, and the continued movement
of the piston moves the valve to service position,
in which port "z" connects with port "h" in the seat
of the valve, as shown in Fig. 9. As the equalizing
slide valve chamber is at all times connected to the
pressure chamber, air can now flow from this chamber
to both the application cylinder and chamber through
ports "z" and "h", cavity "n" and port "w" until
the pressure on the left or pressure chamber side of
the equalizing piston 26 becomes slightly less than
that in the brake pipe, when the piston and graduating
valve will move to the left until the shoulder on the
piston stem strikes the slide valve; this movement of
the graduating valve closes the service port "z", thus
closing the communication between the pressure chamber
and application chamber and cylinder, also closing
port "l" which leads to the safety valve. The distributing
valve is now said to be in service lap position.
(See Fig. 10.)
128. Q. Upon what does the pressure in the application
chamber and cylinder depend when making a
service application of the brake?
A. On the amount of brake pipe reduction; and
as the relative volume of the pressure chamber and
application cylinder and chamber is practically the
same as that of an auxiliary reservoir and brake
cylinder, it will be understood that one pound from
the pressure chamber will make two and one-half
pounds in the application chamber and cylinder; in
other words, with the pressure chamber charged to
seventy pounds and no pressure in the application
chamber and cylinder, if they were connected and
the pressure allowed to equalize it would do so at
about fifty pounds; that is, twenty pounds from the
pressure chamber will make fifty pounds in the application
chamber and cylinder.
129. Q. How is the application piston 10 affected
by the air pressure in the application cylinder "g"?
A. Pressure forming in this cylinder will force the
piston to the right; the piston in moving will carry
with it the exhaust valve 16, closing the exhaust ports
"e" and "d", at the same time moving the application[Pg 204]
valve 5, opening the supply port "b", allowing main
reservoir air from chamber "a" to flow through ports
"b" and "C" to the connection marked "CYLS", and
on to the different brake cylinders of the locomotive
until the pressure in the brake cylinders and at the
right of the application piston becomes slightly greater
than that in chamber "g" when the application piston
and valve will move back to lap position as shown in
Figures 9 and 10.
130. Q. With the application valve in lap position,
if there be brake cylinder leakage, will the locomotive
brake leak off?
A. No; any drop in brake cylinder pressure will
be felt in chamber "b" at the right of the application
piston 10, causing a difference in pressure on the two
sides of the piston, thus allowing the pressure in the
application cylinder to move the application piston
and valve to the right, again opening the supply port
"b" allowing a further flow of main reservoir air from
chamber "a" to the brake cylinders until the pressure
is again slightly greater than that in the application
cylinder "g", when the application piston and valve
will move back to lap position. Thus in this way
air will be supplied to the brake cylinders of the locomotive,
holding the brake applied regardless of
131. Q. What effect will piston travel have on the
pressure developed in the brake cylinders?
A. None; as the pressure in the brake cylinders
is entirely dependent on the pressure in the application
cylinder, which is not affected by piston travel.
132. Q. Explain the movement of the parts in the
valve when the automatic brake valve
is moved to release position, after an automatic application
of the brake.[Pg 205]
A. In release position of the brake valve, air from
the main reservoir flows direct to the brake pipe,
causing a rise of pressure which is felt in chamber
"p" on the right or brake pipe side of the equalizing
piston 26; this increase of pressure will cause the
piston to move toward the left, carrying the graduating
valve 28 and slide valve 31 to release position.
This allows the air from the application chamber and
cylinder to flow to the distributing valve release pipe
"IV" and on through the independent brake valve to
the automatic brake valve, where the port to which
this pipe leads is blanked by the automatic rotary
valve, thus preventing the air from leaving the application
chamber and cylinder, holding the locomotive
brake applied while the train brakes are being released.
The movement of the parts, and the results
obtained are the same where the release is made in
133. Q. Explain the movement of the parts in the
distributing valve when the brake valve is moved to
running position after having first been moved to release
or holding position, following a brake application.
A. In this position of the brake valve the port to
which the distributing valve release pipe is connected
is open to the exhaust, thus allowing the air to escape
from the application chamber and cylinder. The
reduction of pressure in chamber "g", will allow the
brake cylinder pressure in chamber "b" to force the
application piston and its valves to release position,
thus allowing the brake cylinder air to escape to the
atmosphere, through the exhaust ports "e" and "d".
(See Fig. 8.)
134. Q. Explain how an independent release of
the locomotive brake is obtained after an automatic
application has been made.
A. If the brakes have been applied throughout the
train, by means of the automatic brake valve, and it
is desired to release the locomotive brakes without
releasing the train brakes, the handle of the independent
brake valve is placed in release position. In
this position of the independent brake valve, the
application cylinder in the distributing valve is con[Pg 207]nected
through the application cylinder pipe to the
direct exhaust port of the independent brake valve;
thus exhausting the air from the application cylinder,
causing a release of the locomotive brake. This independent
release of the locomotive brake does not
cause the equalizing piston and its slide valve in the
distributing valve to change their position.
135. Q. Explain what takes place when an automatic
emergency application is made.
A. Any sudden reduction of brake pipe pressure
is felt on the brake pipe side of the equalizing piston
26 and will cause it and the slide valve 31 to move
to the extreme right, compressing the graduating
spring 60. (See Fig. 11.) In this position pressure
chamber air can flow to the application cylinder only
as the application chamber is now cut off. This will
cause a quick rise of pressure in the application cylinder,
forcing the application piston and its valves to
full application position, admitting main reservoir air
to the brake cylinders and applying the brake. In
emergency position of the automatic brake valve there
is a small port in the rotary valve, called the blow-down
timing port, through which main reservoir air
is free to flow to the application cylinder "g" through
the application cylinder pipe "II", causing a rise of
pressure equal to the adjustment of the safety valve.
136. Q. At what pressure is the safety valve adjusted?
A. At sixty-eight pounds.
137. Q. What is the purpose of the quick action
cap, and where is it located?
A. Its purpose is to assist the brake valve in
venting brake pipe air when an emergency application[Pg 208]
of the brake is made, and is located on the brake pipe
side of the distributing valve in place of the plain
cap. (See Figs. 8 and 11.)
138. Q. Explain the operation of the quick action
Fig. 11: Emergency Position of No. 6 Distributing Valve with Quick-Action Cap.
A. In an emergency application, the equalizing
piston 26 moves to the extreme right, the knob on
the piston strikes the graduating stem 59, causing it
to compress the graduating spring 46, and move the
slide valve 48 to the right, opening port "j".
Fig. 12: Independent Application.
Brake pipe pressure in chamber "p" flows to chamber "X",
pushes down check valve 53, and passes to the brake
cylinders through port "m" in the cap and distributing
valve body. When the brake cylinders and brake pipe
pressures equalize, check valve 53 is forced to its seat
by spring 54, thus preventing air in the brake cylinders
from flowing back into the brake pipe. When a release
of the brake occurs and piston 26 is moved back
to its normal position, spring 46 forces graduating
stem 59 and slide valve 48 back to release
139. Q. Explain the operation of the distributing
valve when making an independent application of
A. When the independent brake valve handle is
moved to application position, air is admitted from
the reducing valve pipe through the application cylinder
pipe to the application chamber and cylinder.
Pressure forming in the application cylinder will move
the application piston 10 to the right, carrying with
it the exhaust valve 16 and the application valve 5,
closing the exhaust port and opening the supply port,
admitting main reservoir air from chamber "a" to
the brake cylinders (see Fig. 12) until the pressure
in the brake cylinders and chamber "b" slightly exceeds
that in chamber "g", when the application
piston 10 and valve 5 will move back to lap position.
By moving the brake valve handle to either release or
running position, the air is exhausted from the application
cylinder and chamber, thus reducing the pressure
in chamber "g", allowing the pressure in chamber "b"
to force the piston to the left, carrying with it the
exhaust valve 16, opening the exhaust ports "e" and
"d", allowing the air from the brake cylinders to
escape to the atmosphere, thus releasing the brake.[Pg 211]
DISTRIBUTING VALVE DEFECTS
140. Q. If the locomotive brake released with the
automatic brake valve in lap position, where would
you look for the trouble?
A. Would look for a leak in the application cylinder
pipe or in the application cylinder cap gasket.
141. Q. If the brake remained applied in lap position,
but released in release or holding position, where
would you look for the trouble?
A. Would look for a leak in the distributing valve
142. Q. If the distributing valve release pipe and
application cylinder pipe were crossed, what would
be the effect?
A. A brake application made by the automatic
brake valve cannot be released by the independent
143. Q. If the safety valve leaks, what will be
A. This may prevent the brake applying, and in
an independent application if the brake does apply,
it will release when the brake valve is returned to lap
144. Q. If the main reservoir supply pipe to the
distributing valve breaks, what should be done?
A. Plug the pipe toward the main reservoir. The
locomotive brake is lost, but if the distributing valve
is equipped with a quick action cap, when an emergency
application is made, the air coming from the
brake pipe, through the quick action cap, will apply
the locomotive brake.[Pg 212]
145. Q. If the application cylinder pipe breaks,
what effect will it have on the locomotive brake?
A. The locomotive brake cannot be applied with
either automatic or independent brake valve. By
plugging the pipe toward the distributing valve the
automatic brake will be restored.
146. Q. If the distributing valve release pipe
breaks, what will be the effect?
A. The holding feature of the brake will be lost;
that is, the locomotive brake will release when the
automatic brake valve is moved to either release or
holding position, the same as with the old G-6
147. Q. If the release pipe is broken and not
plugged, can the independent brake be applied?
A. Yes, by placing the brake valve handle in
quick-application position the brake will apply, but
there will be a waste of air through the broken pipe,
and the brake will release when the brake valve is returned
to lap position.
148. Q. If the brake cylinder pipe breaks, can the
locomotive brake be applied?
A. This depends on where the pipe breaks; if
between the cut-out cock and any one of the brake
cylinders, close the cut-out cock to that cylinder, and
the other cylinders may be used. But if the pipe
breaks at the distributing valve, the locomotive brake
will be lost.
149. Q. If the brake pipe connection to the distributing
valve breaks, what should be done?
A. Plug the end from the brake pipe; the locomotive
brake must now be released by placing the
independent valve in release position.[Pg 213]
150. Q. If the brake pipe connection to the distributing
valve breaks and is plugged, can the locomotive
brake be operated?
A. The independent brake may be applied and
released in the usual manner, but the automatic brake
will be lost for service braking.
TYPE K TRIPLE VALVE
151. Q. On what is this type of triple valve designed
A. On freight equipment cars only.
152. Q. Explain the operation of the "K" triple
Fig. 13: Full Release and Charging Position.
A. When air is admitted to the brake pipe it is
free to enter the triple at "a" (see Fig. 13) and flow
through the passage "e" to chamber "f", thence
through port "g" to chamber "h" in front of the triple
valve piston 4. Pressure forming in chamber "h" will
force the piston to the left until its packing ring
uncovers the feed groove "i" in the bushing, thus
creating a communication between chamber "h" and
the slide valve chamber. Brake pipe air will now be
free to flow past the piston to the slide valve chamber
and out at "R" to the auxiliary reservoir. Air will
continue to feed through the groove "i" until the
auxiliary reservoir and brake pipe pressures are equal,
and it is then we say that the brake is fully charged.
Brake pipe air entering chamber "a" will lift the check
valve 15, and charge chamber "Y" to brake pipe
pressure. When a gradual reduction of brake pipe
pressure is made, as in a service application of the
brakes, the pressure being reduced in chamber "h",
auxiliary reservoir pressure will move the piston 4
toward service position. (See Fig. 14.) The first
movement of the piston closes the feed groove "i",
thus closing communication between the auxiliary
reservoir and the brake pipe, preventing a back-flow
of air from the auxiliary to the brake pipe, and at
the same time moving the graduating valve 7, opening
the service port "Z" in the slide valve. The continued
movement of the piston will move the slide
valve until the service port "Z" registers with the
brake cylinder port "r" in the valve seat, thus creating
a communication between the auxiliary reservoir and
the brake cylinder. Air will now flow from the
auxiliary to the brake cylinder until the pressure on
the auxiliary side of the piston 4 becomes slightly
less than in the brake pipe, when the piston and the
graduating valve 7 will move back just far enough to
close the service port "Z", thus closing communication[Pg 215]
between the auxiliary reservoir and the brake cylinder.
At the same time, the first movement of the graduating
valve connects the two ports "o" and "q" in the slide
valve through the cavity "v" in the graduating valve,
and the movement of the slide valve brings port "o"
to register with port "y" in the slide valve seat, and
port "q" with port "t". This permits the air in
chamber "Y" to flow through port "y", "o", "v", "q",
and "t", thence around the emergency piston 8, which
fits loosely in its cylinder, to chamber "X" and the
brake cylinder. When the pressure in chamber "Y"
has reduced below the brake pipe pressure remaining in
"a", the check valve 15 is raised and
allows brake pipe air to flow past the check valve
and through the ports above mentioned to the brake
Fig. 14: Quick Service Position.
The size of these ports are so proportioned
that the flow of air from the brake pipe to the top
of the emergency piston 8, is not sufficient to force
the latter downward and thus cause an emergency
application, but at the same time takes enough air
from the brake pipe to cause a local reduction of
brake pipe pressure at that point, thus assisting the
brake valve in increasing the rapidity with which the
brake pipe reduction travels through the train. The
triple valve is now said to be in "Quick Service"
position. (See Fig. 14.)
153. Q. Will the triple valve move to quick service
position whenever a gradual reduction brake pipe
reduction is made?
A. No; with short trains, the brake pipe volume
being comparatively small, will reduce more rapidly
for a certain reduction at the brake valve than with
a long train. Therefore, with a short train, the brake
pipe pressure reducing more quickly, the triple piston
and its valves will move to "full service" position, as
shown in Fig. 15. In this position the quick service
port "y" is closed, so that no air flows from the brake
pipe to the brake cylinder. Thus, when the brake
pipe reduction is sufficiently rapid, there is no need
for this quick service reduction, and the triple valve
automatically cuts out this feature of the valve when
154. Q. How long will the auxiliary reservoir air
continue to flow to the brake cylinder?
A. Air will continue to flow to the brake cylinder
until the pressure on the auxiliary side of the triple piston becomes
less than that on the brake pipe side, when the piston 4 and the graduating valve
7 will move to the left until the shoulder on the piston
stem strikes the slide valve. (See Fig. 16.) This
movement has caused the graduating valve to close
the service port "Z", thus cutting off any further flow
of air from the auxiliary to the brake cylinder and
also port "o", thus preventing any further flow of air
from the brake pipe to the brake cylinder. The triple
valve is now said to be in lap position.
155. Q. How is the triple valve affected by a
further reduction of brake pipe pressure?
Fig. 15: Full Service Position.
A. A further reduction of brake pipe pressure
will cause the triple piston 4 and the graduating valve
[Pg 218]7 to again move to the right, opening ports "Z" and
"o", allowing a further flow of brake pipe and auxiliary
air to the brake cylinder. This may be continued
until the auxiliary reservoir and brake cylinder pressures
become equal, after which any further reduction
of brake pipe pressure is only a waste of air. With
seventy pounds brake pipe pressure, and eight-inch
piston travel, a twenty-pound reduction will cause
equalization at about fifty pounds.
Fig. 16: Lap Position.
156. Q. Explain the operation of the triple valve
in the release of the brake.
A. To release the brakes and recharge the auxiliary
reservoirs, air is admitted through the brake valve[Pg 219]
to the brake pipe. This increase of pressure on the
brake pipe side of the triple valve piston 4 above that
on the other side causes the piston and slide valve
to move back to release position, which permits the
air in the brake cylinder to flow to the atmosphere,
through the exhaust port of the triple, thus releasing
the brake. At the same time, air from the brake pipe
flows through the feed groove "i" around the triple
piston to the auxiliary reservoir, which is thus recharged.
Now the "K" triple valve has two release
positions: Full Release and Retarded Release. To
which of these two positions the parts will move when
the brakes are released, depends upon how the brake
pipe pressure is increased. It is generally understood
that those cars toward the head end of the train, receiving
the air first, will have their brake pipe pressure
raised more rapidly than those in the rear; thus the
friction of the brake pipe causes the pressure to build
up more rapidly in the chamber "h" of the triple valve
toward the front end of the train than in those in the
rear. As soon as the pressure is enough greater than
the auxiliary reservoir pressure to overcome the friction
of the piston, graduating valve and slide valve,
all three are moved toward the left until the piston
stem strikes the retarding stem 31, which is held in
position by the retarding spring 33. Where the rate
of increase of brake pipe pressure is slow, it will be
impossible to raise the pressure in chamber "h" sufficiently
to overcome the tension of the retarding
spring 33, and the triple valve will remain in full
release position, as shown in Fig. 13. Brake cylinder
air will now be free to exhaust through port "r", large
cavity "n" in the slide valve and port "p" leading to
the atmosphere. If, however, the triple valve is near
the head end of the train, and the brake pipe pressure
builds up more rapidly than the auxiliary can recharge,
an excess of pressure will be obtained in[Pg 220]
chamber "h" over that in the auxiliary reservoir, and
will cause the piston 4 to compress the retarding spring
33, and move the triple valve parts to retarded release
position as shown in Fig. 17.
157. Q. What effect has retarded release position
of the triple valve on the release of the brakes?
A. In this position of the triple valve, cavity "n"
in the slide valve connects port "r" leading to the
brake cylinder, with port "p" to the atmosphere, and
the brake will release; but as the small "tail port"
extension of cavity "n" is over exhaust port "p", the
discharge of air from the brake cylinder is quite slow.
Fig. 17: Retarded Release and Charging Position.
158. Q. What is the object of delaying the exhaust
of the brake cylinder air?
A. In this way, the brakes on the front end of the
train require a longer time to release than those on
the rear. This feature is called retarded release, and
although the triple valves near the locomotive commence
to release before those in the rear, yet the
exhaust of air from the brake cylinder is sufficiently
slow to hold back the release of the brakes at the
front end of the train long enough to insure a uniform
release of the brakes on the train as a whole. This
permits of releasing the brakes on very long trains
at low speeds without danger of damaging train.
159. Q. What other desirable feature is found in
this position of the triple valve?
A. In this position, the back of the piston is in
contact with the end of the slide valve bush, and, as
these two surfaces are ground to an accurate fit, the
piston makes a tight "seal" on the end of the bush
except at one point, where a feed groove is cut in the
piston to allow air to pass around the end of the slide
valve bush into chamber "R" and the auxiliary reservoir.
This feed groove is much smaller than the feed
groove "i" in the piston bush, so that when the triple
valve piston is in Retarded Release position the recharge
of the auxiliary reservoir takes place much
more slowly than when it is in Full Release position,
thus permitting a greater volume and pressure of air
to flow toward the rear of the train.
160. Q. Explain the operation of the triple valve
in emergency position.
A. When any sudden reduction of brake pipe
pressure is made below that in the auxiliary reservoir,
it will be felt in chamber "h" in front of piston 4 and
cause this piston to move to the extreme right, as
shown in Fig. 18. This movement of the parts will
open port "t" in the slide valve seat and allow air
from the auxiliary reservoir to flow to the top of the
emergency piston 8, forcing the latter downward and
opening emergency valve 10. The unseating of the
emergency valve allows the air in chamber "Y" to
escape to the brake cylinder, thus permitting brake
pipe pressure in chamber "a" to lift the check valve
15 and flow to the brake cylinder through chambers
"Y" and "X", until brake cylinder and brake pipe
pressure nearly equalize, when the check valve is
forced to its seat by the check valve spring 12, preventing
the air in the cylinder from escaping back[Pg 223]
into the brake pipe again. The emergency valve and
piston will now return to their normal position. At
the same time port "s" in the slide valve registers with
port "r" in the slide valve seat, and allows air from
the auxiliary reservoir to flow to the brake cylinder.
This sudden discharge of brake pipe air into the brake
cylinder has the effect on the next triple valve, which
in turn vents brake pipe air that affects the following
triple valve and so on throughout the train.
NEW YORK AIR BRAKE
161. Q. What do Figures 19 and 20 represent?
A. These are cross-sectional views of the New
162. Q. Of what does the valve gear of this compressor
A. Of two main valves, actuated by tappet rods
which enter into the hollow piston rods, and are
moved by tappet plates, which are fastened to the
steam piston heads.
163. Q. How is the admission and exhaust of
A. The valve under the cylinder at the right controls
the flow of steam to and from the cylinder at the
left; while the valve under the cylinder at the left
controls the flow of steam to and from the cylinder
at the right.
164. Q. Explain the operation of the steam end
of the compressor.
Fig. 19: Low Pressure Piston Moving Upward. High Pressure Piston at Rest.
[Pg 225]A. Assuming
both pistons are at the bottom of
their cylinders, when the compressor throttle is opened,
live steam will flow to both steam chests "B" (see
Fig. 19), and through port "o" to the under side of
the piston "T" and through port "g" to the upper
side of piston "H". The steam under piston "T" will
force it upward, and when it very nearly completes
its stroke, the tappet plate "Q" will engage the button
on the end of the tappet rod "P", moving the main
valve "C" to its upper position. In this position the
exhaust cavity "r" in the main valve connects port
"g" with the exhaust port "X", thus allowing steam
above the piston "H" to escape to the exhaust, at the
same time steam is admitted through port "s" to the
under side of piston "H", forcing it upward. As this
piston very nearly completes its stroke, the tappet
plate "L" (see Fig. 20) engages the button on the
tappet rod "P", moving the main valve "A" to its
upper position. Exhaust cavity "r" now connects
port "o", which leads to the lower end of the cylinder
at the right, with the exhaust port "X", thus allowing
the steam under piston "T" to escape to the exhaust,
at the same time steam is admitted through port "V"
to the upper end of the cylinder at the right, on top
of piston "T", forcing it downward; as it very nearly
completes its stroke, the tappet plate "Q" engages the
shoulder on the tappet rod "P", moving the main
valve "C" to its lower position. The exhaust cavity
"r" in the valve now connects port "s" with the exhaust
port "X", allowing steam below piston "H" to
escape to the exhaust, and at the same time steam is
admitted to the top of this piston, forcing it down,
thus completing a cycle of the compressor.
165. Q. Explain the operation of the air end of
A. As the piston in the low pressure cylinder "D"[Pg 226]
moves up (see Fig. 19), a partial vacuum is formed
below it, and air flowing through the strainer passes
downward through the air passage, then past the lower
receiving valve "W" into the lower end of the cylinder,
filling it with air at about atmospheric pressure. In
the meantime the air that is being compressed above
the piston holds the receiving valve "U" to its seat,
and lifts the upper intermediate discharge valve "K"
from its seat, allowing the air to pass from the low to
the high pressure cylinder "F". The high pressure
piston now moving up causes a partial vacuum to be
formed below it, and air from the atmosphere flows
past the lower receiving valve "N", filling this end of
the cylinder with air at about atmospheric pressure.
The air above the piston being compressed, holds the
upper intermediate valve "K" and receiving valve "J"
to their seats and lifts the upper final discharge valve
"M", allowing the air to pass to the main reservoir.
The action is the same on the down stroke, only air
is compressed in the opposite end of the cylinders
and the opposite air valves are used.
166. Q. What should be the lift of the different
A. In the No. 1 and No. 2 compressors all valves
should have 1/16-inch lift; in the No. 5 and No. 6 all
valves should have 3/16-inch lift.
167. Q. If a receiving valve to the low pressure
air cylinder breaks or sticks open, what effect will it
have on the compressor, and how may it be located?
A. No air will be compressed in the low pressure
cylinder, as the piston moves toward the defective
valve, and may be located by noting the movement
of the low pressure piston, as it will be much quicker
toward the defective valve than the opposite stroke.
Air will blow back to the atmosphere as the piston[Pg 227]
moves toward the defective valve, and may be detected
by holding the hand over the strainer.
168. Q. If an intermediate discharge valve breaks
or sticks open, what effect will it have on the compressor,
and how may it be located?
A. If an intermediate discharge valve breaks or
sticks open, no air will be compressed by that end of
the compressor where is located the defective valve,
as the air will simply flow back and forth from the
high to the low pressure cylinders; no air will be
taken in from the atmosphere through the strainer
as the pistons move from the defective valve.
169. Q. If a final discharge valve breaks, what
effect will it have on the compressor?
A. Main reservoir air will be free to return to the
high pressure cylinder as the high pressure piston
moves from the defective valve; therefore, no air will
be taken in through the receiving valve of the high
pressure air cylinder at the end where is located the
defective valve. The low pressure piston will make
a slow stroke toward the defective valve and a normal
stroke from it; while the high pressure piston will
make a slow stroke toward the defective valve and
a quick stroke from it. Defective air valves may
generally be located by noting the temperature of the
valve chamber in which they are located.
170. Q. What will cause the compressor to run hot?
A. Running the compressor too fast; working
against high pressure; air piston packing rings leaking;
air cylinder worn; air passages or discharge pipe
partially stopped up; air valves leaking; air valves
stuck shut; or lack of lubrication.
171. Q. How should the air end of the compressor
be oiled, and what grade of oil used?[Pg 228]
Fig. 20: High Pressure Piston Moving Upward. Low Pressure Piston at Rest.
A. Oil should be used sparingly in the low pressure
cylinder, but more is required in the high pressure
cylinder, owing to higher temperature. A good quality
of valve oil should be used.
172. Q. How is the steam end of the compressor
affected by the use of too much oil?
A. This may cause the compressor to short stroke,
and where the piston type of valve is used, may cause
the compressor to stop.
AUTOMATIC CONTROL VALVE
173. Q. What is the duty of the control valve?
A. To admit air from the main reservoir to the
locomotive brake cylinders when applying the brakes;
to automatically maintain the brake cylinder pressure
against leakage; to develop the proper brake cylinder
pressure regardless of piston travel; and to exhaust
the air from the brake cylinders when releasing the
brake, in all automatic applications of the brake.
174. Q. Explain the operation of the control valve
when making an automatic service application of the
A. Air enters the control valve at the connection
marked "BP" (Fig. 21), which leads to chamber "F"
above the piston 3, forcing it down, uncovering the
feed groove "G" in the bushing, allowing air to feed
past the piston into the slide valve chamber, and then
through port "H" to the auxiliary reservoir. The air
will feed through in this manner until the auxiliary
reservoir and brake pipe pressure equalize. When a
gradual reduction of brake pipe pressure is made, it[Pg 230]
will be felt in chamber "F", above piston 3, creating
a difference in pressure on the two sides of the piston,
which will cause it to move upward.
Fig. 21: Automatic Control Valve. Full Release.
The first movement of the piston closes the feed groove "G", also
moves the graduating valve 10, uncovering the service
port "J" in the slide valve 4, and the continued movement
of the piston moves the slide valve to service
position, in which the service port "J" connects with
port "E" in the valve seat. (See Fig. 22.) As the
slide valve chamber and auxiliary reservoir are connected
at all times, air can now flow from the auxiliary
to the control cylinder "D" and control reservoir,
through ports "H", "J" and "E", until the pressure
on the lower or auxiliary side of piston 3 becomes
slightly less than that in chamber "F" or brake pipe
side, when the piston and graduating valve will move
down until the shoulder on the piston strikes the slide
valve; this movement of the graduating valve closes
the service port "J", thus closing the communication
between the auxiliary and control cylinder and reservoir,
also closing port "W", which leads to the safety
valve. (See Fig. 23.)
175. Q. How is piston 2 affected by the air pressure
in the control cylinder "D"?
A. Pressure forming in this cylinder will force the
piston downward. The piston in moving down will
carry the exhaust valve 7 with it, closing the exhaust
port "N" and moves the preliminary admission valve
"1A" from its seat against the tension of spring 8,
allowing the pressure in chamber "O" to pass to the
brake cylinders, thus creating a balancing effect on
valve 1, which allows it to be opened against main
reservoir pressure, thus allowing main reservoir air to
flow from chamber "A" to chamber "B" and the
brake cylinders on the locomotive (see Fig. 22) until
the pressure in the brake cylinders and chamber "B",
below piston 2, becomes slightly greater than that in
the control cylinder "D" when the piston will move
up just far enough to allow the valves "1" and "1A"
to be seated, or to lap position. (See Fig. 23.)
Fig. 22: Automatic Control Valve. Service Position.
176. Q. With the control valve now in lap position,
will the brake release on account of brake cylinder
A. Any drop in brake cylinder pressure will be
felt in chamber "B" below the piston 2, causing a difference
in pressure on the two sides of the piston,
allowing the pressure in the control cylinder "D" to
move the piston 2 down, unseating the admission
valves, allowing a further flow of main reservoir air
from chamber "A" to chamber "B" and the brake
cylinders until the pressure is again slightly greater
than that in the control cylinder "D", when the piston
2 will again move up, allowing the admission valves
to close. Thus in this way air will be supplied to the
brake cylinders of the locomotive, holding the brakes
applied regardless of leakage.
177. Q. Explain the movement of the parts in the
control valve, when the automatic brake valve is
moved to release position, following an automatic
application of the brake.
A. In release position of the brake valve, air from
the main reservoir flows direct to the brake pipe,
causing an increase of pressure, which is felt in chamber
"F" on the upper side of piston 3; this increase
of pressure will cause the piston to move down, carrying
with it the graduating valve 10 and slide valve 4
to release position. This allows air from the control
cylinder "D" and control reservoir to flow through the
release pipe "IV" and on to the automatic brake valve,
where the port to which this pipe leads is blanked by
the automatic rotary valve, which prevents the air
leaving the control cylinder and reservoir, thus holding
the locomotive brake applied while the train brakes
are being released. The movement of the parts are
the same where the
is made in holding position.
178. Q. Explain the movements of the parts in the
control valve when the automatic brake valve is
moved to running position, after having first been
moved to release or holding position.
Fig. 23: Automatic Control Valve. Service Lap Position.
A. In this position of the brake valve the port to
which the release pipe "IV" is connected is open to
the exhaust, thus allowing the air in the control cylinder
and reservoir to escape to the atmosphere. The
reduction of pressure in the control cylinder "D" below
that in chamber "B" causes the control piston 2
to move up, carrying with it the exhaust valve 7 to
release position, opening the exhaust port "N", thus
allowing the air to return from the brake cylinders
through ports "C" and "N" to the atmosphere, releasing
the brake. (See Fig. 21.)
179. Q. Explain what takes place in the control
valve when an automatic emergency application of
the brake is made.
A. Any sudden reduction of brake pipe pressure
will be felt on the brake pipe side of piston 3, and will
cause it and the valve 4 to move to their extreme
upper position, the knob on the piston striking the
graduating stem 13, causing it to compress the spring
14, moving the emergency valve 15 upward, opening
port "Q"; this allows brake pipe air to flow against
valve 16, unseating it, then through port "T" to the
brake cylinder. (See Fig. 24.) In the meantime
auxiliary reservoir air can flow past the end of the
slide valve through port "E" to the control cylinder
"D" and control reservoir, forcing piston 2 downward
unseating valves "I" and "IA", thus allowing main
reservoir air to flow to the brake cylinders, applying
180. Q. At what pressure will the auxiliary reservoir
and control reservoir equalize when using seventy
pounds brake pipe pressure?
A. At about fifty pounds; however, with the automatic
brake valve in emergency position, there is a
small port in the rotary valve (called the blow-down[Pg 236]
timing port) opened to the control reservoir pipe and
control reservoir which allows main reservoir air to
flow to the control reservoir and cylinder, raising the
pressure to the adjustment of the safety valve.
Fig. 24: Automatic Control Valve.
Emergency Position. (With Quick Action Cylinder Cap.)
181. Q. At what pressure is the safety valve adjusted?
A. At fifty pounds.
182. Q. What types of brake valve are used with
A. The automatic brake valve is of the rotary
valve type and is the same valve as used with the E-T
equipment. The straight air brake valve is of the slide
valve type. The control valve takes no part in the
application or release of the straight air brake. What
has been said of the H-6 brake valve used with the
E-T equipment, applies to the automatic brake valve
used with the L-T equipment.
183. Q. If the main reservoir supply pipe to the
automatic control valve breaks, what should be done?
A. Plug the pipe toward the main reservoir. The
locomotive brake cannot be applied in an automatic
service application; but if the control valve be
equipped with a quick action cap and an emergency
application is made, the air vented from the brake
pipe to the brake cylinder will apply the brake. The
independent brake will not be affected.
184. Q. What will be the effect if the release
A. The holding feature of the brake will be lost;
that is, the brake will release when the automatic
brake valve is returned to release or holding position.[Pg 238]
185. Q. If the brake cylinder pipe breaks, can the
locomotive brake be applied with the automatic brake
valve? With the independent brake valve?
A. This depends on where the pipe breaks; if
between the cut-out cock and any one of the brake
cylinders, close the cut-out cock to that cylinder, and
the other cylinders may be used. But if the pipe
breaks between the control valve and the double-throw
check valve, the automatic brake is lost; if the
break be between the independent brake valve and
double-throw check valve, the independent brake
186. Q. If the brake cylinder pipe breaks and is
not plugged, what must be done?
A. Close the cut-out cock in the main reservoir
supply pipe, this to avoid the waste of air when a
brake application is made on the train.
187. Q. If the brake pipe connection to the control
valve breaks, what should be done?
A. Plug the end leading from the brake pipe;
the automatic brake cannot be applied on the locomotive,
but the independent brake will not be affected.
188. Q. If the control cylinder pipe breaks, what
effect will it have and what must be done?
A. The locomotive brake cannot be applied with
the automatic brake valve; by plugging the pipe, this
feature of the brake will be restored, but the independent
release feature will be lost.
189. Q. If any of the pipes here enumerated breaks,
will it in any way affect an application of the independent
A. No; as the independent and automatic features
are entirely separate from each other; that is, the
automatic control valve is not brought into use when
an independent application of the brake is made.
CONTROL VALVE DEFECTS
190. Q. If there is a blow at the control valve
exhaust port when the brake is released, where would
you look for the trouble?
A. This would indicate a leaky application valve,
or a leak past the emergency valve.
191. Q. If there be a continuous blow at the control
valve exhaust port when the brake is applied,
where would you look for the trouble?
A. This would indicate leakage past the exhaust
192. Q. If the locomotive brake released with the
automatic brake valve in lap position, where is the
A. Would look for a leak in the control reservoir
pipe or special release valve.
193. Q. If the brake remained applied in lap position,
but released in release or holding position, where
would you look for the trouble?
A. This would indicate a leak in the control valve
194. Q. What is meant by an application of the
A. The first and all following reductions, until the
brake is released.[Pg 240]
195. Q. How many applications of the brake
should be made when making a stop with a passenger
train, and why?
A. Two; the first a heavy one to reduce the speed
quickly, and the second a light one to complete the
stop; thereby preventing wheel sliding and shock to
196. Q. How many applications of the brake
should be made when making a stop with a long
A. One; this to prevent the possibility of causing
damage to the train.
197. Q. Explain how a stop should be made with
a freight train.
A. Probably no more difficult question to answer
could be asked, as the service braking of a train must
be governed by the condition surrounding it; meaning,
relation of brake power to weight of train; rail condition;
speed and grade. To prevent breaking in two
and other damage, freight trains should be stopped
with one brake application, which may consist of one
or more reductions, up to full service. Generally
speaking, the slack should be bunched before the
brakes are applied, and this may best be done by
gradually closing the throttle and allow the train to
drift some little distance. The first reduction should
not be less than five or more than eight pounds. The
brakes should be applied as soon as possible after
the slack has had time to run in, the object of this
being to have the train slack adjusted while the brakes
are least effective, due to the high speed and light
brake cylinder pressure. It is at this time that damage
may be done to the train; therefore, if the slack be
kept bunched or stretched, as the case may be, the[Pg 241]
possibility of train damage will be greatly reduced.
To obtain this condition, complete the stop with as
light a brake application as permissible. When the
brake is first applied, the engineer should note if the
tendency be for the train slack to bunch or stretch,
and having learned that the train is inclined to stretch
badly, he can keep the slack stretched by making the
initial brake pipe reduction before shutting off steam,
then shut off steam gradually as soon as the brake
valve exhaust port closes, the object in working steam
being to prevent the slack running in as the application
is made, which in turn will prevent severe jerks
due to the slack running out as the rear brakes become
effective. Where the locomotive is equipped
with an independent release feature, its brakes should
be kept released while the train brakes are being
198. Q. Is it considered good practice to attempt
making an accurate stop with a freight train?
A. It may be said to be very poor judgment to
attempt making an accurate stop with a freight train,
such as a spot stop for coal or water or a close-up
stop for a switch. Some engineers seem to think that
it is a reflection on their judgment if an accurate stop
is not made, but this is not so, due to the fact that no
two trains brake alike, and the same train may not
brake twice alike. Therefore, aim for a smooth stop,
which means a safe stop, leaving accuracy out of the
question until the time comes when you are handling
a passenger train.
199. Q. What precaution should be taken after
a stop is made on a heavy grade?
A. The air brakes should be released and a sufficient
number of hand brakes applied to hold the[Pg 242]
train. Never rely on the air brake to hold the train
for any length of time.
200. Q. Why is it dangerous to repeatedly apply
and release the brakes without giving time for the
auxiliaries to fully recharge?
A. As time is required to charge the auxiliaries,
the feed groove in the triple valve being small, if the
brakes are repeatedly applied and released without
giving time to recharge, the braking power will be lost.
201. Q. What benefits are derived from the use
of the retaining valve?
A. By use of the retaining valve the brake is held
applied while the triple valve is in release position and
the auxiliary is being recharged; thereby assisting in
retarding the movement of the train down grade, also
keeps the train bunched and gives a higher brake
power on the second application with the same reduction
of brake pipe pressure.
202. Q. With a seventy-pound brake pipe pressure
how much of a reduction is necessary to set the brakes
in full, and why?
A. About twenty pounds. This will cause the
auxiliary reservoir and brake cylinder pressures to
203. Q. What effect has piston travel on the pressure
developed in the brake cylinder?
A. The longer the piston travel the greater the
volume or space to be filled with air; therefore the
lower the pressure.
204. Q. When should brakes be tested?
A. Brakes should be tested before leaving a terminal
and after any change in the make-up of the[Pg 243]
train, at all designated points, also, whenever the
engineer is in doubt as to his having the control of
205. Q. How should a terminal test of the brakes
A. After the pressure is pumped up, a reduction
of about ten pounds should be made and the length
and force of the brake pipe exhaust should be noted,
also the manner in which the exhaust closes; then a
further reduction of ten pounds should be made and
the brake held applied until signaled to release.
206. Q. If, when making a service application of
the brake, the brake pipe exhaust closes suddenly and
begins to blow again, what does it indicate?
A. That the brakes, or at least part of them, have
applied in quick action.
207. Q. What is meant by a running test, and
when should this test be made?
A. A running test is made while the train is in
motion, and steam is being used, when a sufficient
reduction should be made to apply all brakes. After
noting the efficiency of the brakes they should be
released. Running tests should be made following all
standing tests and at all other points on the road as
required by the rules.
208. Q. When double-heading, which engineman
should have full control of the brakes?
A. The head engineer; the cut-out cock under
the brake valve on the second engine should be closed
and the compressor allowed to run.
209. Q. How may the engineman assist the trainman
in finding a bursted hose?[Pg 244]
A. After the train has come to a stop, the brake
valve should be placed in running position; by so
doing, air will be admitted to the brake pipe and
cause a blow at the point where the hose is burst.
210. Q. If the locomotive brake creeps on with
the automatic and independent brake valves in running
position, where would you look for the trouble?
A. This is caused by the pressure chamber being
overcharged or a non-sensitive feed valve allowing
brake pipe pressure to vary, which in turn causes an
automatic application of the brake.
211. Q. How often should the main reservoir be
A. The main reservoir should be drained at the
beginning of each trip.[Pg 245]
Air Brake Questions, First Series, 22
Air Brake Questions, Second Series, 44
Air Brake Questions, Third Series, 164
Compound Locomotives, 98
Examination Questions, First Series, 7
Examination Questions, Second Series, 25
Examination Questions, Third Series, Mechanical, 62
Federal Regulations, 126
Headlight, Pyle National, 127
Headlight, Schroeder, 141
Headlight, "Buda-Ross" Electric, 143
Oil Burning Locomotives, 47
Southern Valve Gear, 119
Stoker, Duplex, 154
Walschaert and Baker-Pilliod Valve Gears, 113