SOME TECHNICAL POINTS EXPLAINED
NOW that I am a retired engineer, I wish to give others the
benefit of my long and varied experience in handling a locomotive.
Every engineer knows how essential it is to be able to locate
the trouble when anything goes wrong with his engine, but it takes
years of experimenting to be able to do this accurately, so I
will here add some helpful information in the form of questions
and answers. I have asked hundreds of engineers for the solution
of these problems, and put the same questions to master mechanics
without once receiving a correct answer.
QUESTION 1: Why is it that the guides of a locomotive
run dry and chafe quicker backing up than when going ahead?
ANSWER: When an engine is running in forward motion, there
is an angle formed at the front end of the main rod with the cross-head.
Working steam in this motion causes the cross-head to press the
top guide, so long as the engine is running forward. The weight
of the main rod, cross-head, and piston rod counteracts the power
generated, by working steam to the amount of the weight in said
rod, cross-head, and piston rod, which gravity controls. In back
motion, it is the contrary, the weight being put on the bottom
guide and power of the engine also. I have never figured out how
much more friction there is on the bottom guide in backing up
than on the top guide in running ahead, but it can be readily
seen that you have all .the weight of the main rod, cross-head,
and piston rod in addition to the power of the engine, when running
backward. I reasoned this out while I had charge of my first regular
engine in 1861, when running a construction train on the Memphis
and Charleston railroad.
QUESTION 2: How do you locate the blow on an engine?
ANSWER: Watch the top of the stack when the fireman throws
coal into the fire-box, after the door is shut. If the engine
is not blowing, the smoke will come out of the stack in a twist
on both sides. If blowing on either side, the smoke will not twist
on that side, so if she is blowing on both sides, the smoke will
not leave the stack in a twist on either side. I learned this
fact from observation while still a young man, and have never
placed an engine as others do, to locate the blow, in forty-five
QUESTION 3: Why do engines gum up their cylinder packing
piston rods, and valve stems?
ANSWER: Because the valve-rod, which is the most important
part of the valve motion of a locomotive, is not the proper length.
There was an engine overhauled in the Selma shops over thirty
years ago, that was so gummed up in valve stems and piston rods
that she could not be run more that one trip without packing the
piston stuffing boxes. In those days, we used fibrous packing
for the purpose. I told the Master Mechanic that if he would let
me run that engine a trip, I would stop her from gumming up. He
made no reply, but looked at me in a doubtful manner and walked
off. For three months he and the Engineer worked on her trying
to overcome this defect, but without success. At last, he said
to me, "John, I am going to let you run the a I a trip, as
you say you can stop her from gumming up, for I have done everything
in my power and failed." I replied, "You don't know
where the trouble is. I will fix her before I return to Selma."
I did so. This one thing has been a standing puzzle not only to
the men and foremen of the Selma shops, but all over the United
States, Canada, and Mexico. The way to get the proper length of
a valve-rod is to cover the ports exactly, then plumb the rocker
arm, and that will give the exact length of the valve rod. The
foremen and master mechanics with whom I have come in contact
think this is not very important, but experience has taught me,
that if the valve-rod is not the proper length, you cannot set
the valves to be perfectly square. I have known foremen to have
the valve-rod shortened or lengthened to divide the travel of
the valve, which is an error, because it changes the speed in
the travel of the valve in crossing the centre, which I will illustrate.
If the valve-rod is not the proper length it will not travel at
the same speed from one point to another in its extreme limit.
We all know that when engines are drifting, a vacuum is formed
at each end of the cylinder. By having this valve-rod accurate,
the propelling power overcomes the vacuum to such an extent that
it prevents the sediment in the front end from reaching the cylinders
and steam chest, through the exhaust pipes.
QUESTION 4: Why is it that locomotives wear their tires
flat at certain points?
ANSWER: Because of the construction of the locomotive. The
greatest wear on a tire is when the engine is leaving its forward
centre, because the crank is between the wheel centre and the
fulcrum, which is the rail. The power turning the wheel has a
tendency to skid it, and does skid it on the rail every revolution
while working steam. The flat spot on the tire, caused by leaving
the back centre, is not as long as the one leaving the forward
centre, because the leverage is not between the wheel centre and
the fulcrum, which is the rail; so all the skid on that centre
is to take up the lost motion in boxes and side rods. Thus, in
order to overcome this defect keep boxes in good shape, wedges
set up properly, and the lost motion taken up in side rods. Men
in various railroad departments, even superintendents of motive
power on the various systems all over the country have failed
to explain this point scientifically. Some have advanced one idea
and some another. I asked a master mechanic once if this question
was ever taken up by their Association, while in conventions.
He replied that it was. I then requested him to explain it to
me. He said, that as the engines wore their tires faster on level
roads, they had attributed it to sand. I gave him my reason as
stated above, illustrating it with a bicycle, whereupon he acknowledged
the solution to be entirely satisfactory. That man is now Superintendent
of Motive Power for the Mobile & Ohio System. I don't know
whether he gave the secret away or not, but I do know that I am
the originator of it.
QUESTION 5: How is it necessary to proceed when anything
happens to the valve motion, so that the engine has to be put
on one side?
ANSWER: They are liable to stop on the centre, and the present
mode of getting them off by pinching, or jacking, is an uphill
business; in fact, almost an impossibility with the up-to-date
locomotive and the number of men now on the trains. When an engine
is disabled as stated, the main rod must not be disconnected,
for should she stop on a dead point on the live side, the valve
can then be changed on the dead side, so as to move her off the
dead point on the live side. Then cover the ports on the dead
side and she is ready to do business on the live side. The superintendent
of motive power or master mechanic may say that the cylinder packing
or piston head will run dry and chafe, but if you will feed your
lubricator more on the lame side than you would ordinarily, it
will not chafe either cylinder or cylinder packing, because there
is always a small leakage between valve and seat, which will allow
steam and oil to pass into the cylinder. If there should be any
oil left in the steam chest, when the engine is drifting, the
vacuum formed by the piston head will take it all in, as well
as any that may feed in from the lubricator while the engine is
drifting. The piston rod should be lubricated at the gland, by
means of a cup, or swab, to prevent the piston rod from becoming
heated from the piston rod packing.
QUESTION 6: Why is it that locomotives do not drift
as we think they should?
ANSWER: Several defects may be mentioned that will retard the
drifting. Sometimes engines are not properly quartered; sometimes
they are out of tram; side rods not the proper length; or want
of lubrication in machinery and cylinders. But the main cause
is due to the use of valve cylinder cocks. When an engine is drifting,
a vacuum is formed by the piston head, and atmospheric pressure
fills the cylinder with air at every revolution. This air cannot
pass out through the cylinder cock, so the piston head has to
force it from the cylinders through the openings, or ports, in
valve and valve seat; therefore, it retards the drifting of a
locomotive more than all other impediments mentioned, and plug
cylinder cocks should be used instead of valve cocks. There would
be very little, if any, air drawn into the cylinder, if plug cocks
were used, because the propelling power would overcome the vacuum,
and allow engines to drift as they should. Relief valves and valve
cylinder cocks are impediments to a locomotive, for another reason.
While locomotives are drifting, cold air rushes in at these openings
and chills the cylinder and steam chest away below the temperature
of steam, thereby causing condensation in cylinder and steam chest,
until heated to the same temperature as steam. If any one doubts
this statement in regard to valve cocks and relief valves, just
let him get the superintendent of motive power to fit up a locomotive
with plug cylinder cocks, and it will verify my words. I was talking
with a superintendent of motive power a year ago about the different
builds of locomotives and their deficiencies. We finally took
up the Mallet Compound Locomotive, which, he said, scarcely drifted
at all. I asked him if he knew the reason for this. He replied
that it was on account of its length, numerous bearings, and friction.
I told him that there was a scientific reason why they did not
drift as well as any other locomotives, in comparison with the
size, and would like him to point it out to me. He said he was
not able to do that. I told him if he would give the problem a
little thought, he could solve it, but he decided that he had
so many things to occupy his time and attention that he could
not put his mind upon that subject just then. I asked him if he
had road foremen of engines on his system. He replied in the affirmative,
adding that they were as good as any on any system. I then requested
him to put this matter before them, and asked that they report
to him as early as possible. I have frequently met this gentleman
since, but he has never mentioned the subject, therefore, it is
very evident that his foremen have not given him the desired information.
Now, Brothers, just take a common-sense view of this matter! There
are two cylinders twenty-two inches in diameter, and two that
are thirty-two inches in diameter, which will fill with air under
the present construction of cylinder cocks and relief valves.
Now, it is clear to any thinking man that this air, having to
be forced out by the piston head, will undoubtedly retard the
speed of the engine at every revolution, and, hence, is the chief
cause why the Mallet Compound Locomotive does not drift as it
should. This defect can be remedied as above stated.
QUESTION 7: What is the duty of the engine, or pony
ANSWER: Most any one would say "to carry the weight of
the front of the engine." It has an additional use. It entirely
controls the tracking of a locomotive while running forward or
backward, which is a very important part of the work. This truck
is generally left to be fitted up and looked after by what is
considered a third-class workman, which should not be the case.
Only a first-class mechanic should build and adjust it, for when
it is in perfect order with wheels, etc., an exact match, and
the male casting attached to cylinder saddles precisely in the
centre of the two cylinders, the engine will track to perfection
in both motions. About twenty years ago, this road received five
passenger locomotives, four of which performed all right, but
the remaining one rode so rough that the Engineer in charge made
complaint to the Master Mechanic. He also spoke of it to his Brother
Engineers, and talked it to everybody he came across. The master
mechanic, Mr. Petrican, and a number of engineers rode on No.
163 a number of times in the course of five months, but couldn't
locate the trouble. It so happened at one time that this engine
ran as first section, and mine as second section of the same schedule,
one hundred and twenty miles from Selma. We had a meeting point
with another train, and having to wait twenty minutes, I ran up
behind section number one, and getting off my engine, went forward
to have a conversation with the Engineer. He was lying on the
platform, and when I asked him what was the matter, he answered,
"That engine is killing me!" "What is the trouble?"
I said. He replied that he didn't know. This was three-thirty
A.M. He asked me if I would run the 163 to Anniston, a distance
of twelve miles. I did so, and before going half the distance,
found the trouble to be in the engine truck. Upon coming up with
me at Anniston he wanted to know what I thought of her. My reply
was, "She is a holy terror!" When I told him that the
rough riding was due to the engine truck, he did not credit it,
and said he wouldn't report that to the Master Mechanic, for the
truck was all right. I then said, "Well, tell him that I
say there is a deficiency in the truck." He agreed to that,
and when Mr. Petrican made the examination, he discovered that
the wheels varied as much as a quarter of an inch in diameter.
This defect was remedied, and the engine went out on the road
in a much better condition, though at times she would have what
we engineers called "fits," when she would run fast
on straight lines. Later on, that engine was turned over to me,
and when I would get her to a high rate of speed, she had "fits"
with me. I asked the Foreman to examine her and find out if the
male casting on the cylinder saddle, which set in the female casting,
was in the center of the cylinders. He discovered it was nearly
three sixteenths out. He adjusted this properly, and the engine
was all right, and as good a riding engine as one could put foot
About five years ago, the General Superintendent of the Western
District of the Southern .Railway told me in Rome, Georgia, that
they had a passenger engine that cut up in such a manner, when
run at a high rate of speed on a straight line, that a man would
believe she was off the track, and that upon the occasion of one
of her spells a fireman had jumped off. "The fact,"
said he, "was reported to me, so I took a ride on the crazy
locomotive myself, and she rode so rough that I actually couldn't
sit on the seat box. I asked the engineer in charge how long she
had been in that condition. He replied that it had been that way
ever since he had started to run her, and added that the engine
had been worked on for some time, but the trouble had not been
located. Now, I want you to tell me where the deficiency is."
I answered that if he would keep it to himself, I would do so.
I then explained to him what I have already said in regard to
engine 163, and asked him to go to the shops and investigate the
matter for himself. In a short time the engine was put back into
service, and there has been no complaint about her, on that point,
since. This defect can be partially overcome by giving an inch,
or more, lateral motion between the hubs and boxes of the truck,
when the trouble is only in the male casting.
QUESTION 8: How can you tell when the male casting of
the engine truck is not in the centre of the weight in front of
the locomotive, and how can it be overcome?
ANSWER: When it is not in the centre, the locomotive will always
run to the light side, therefore, to overcome this, simply put
more weight on that side, which will make truck and driving wheels
run straight on the track, if the weight is equally divided on
the engine truck. I have known master mechanics and foremen to
throw the driving wheel back on one side as much as an eighth
of an inch to avoid cutting the flanges on the opposite side,
and I have never yet seen that it made any difference in the tracking
of the engine. It only makes the boxes run hot, and the engine
ride rough. Think of a wagon or any kind of a vehicle. We all
know that the front wheels control the tracking of the back wheels;
in the same manner the front truck controls the tracking of the
driving wheels of a locomotive, in both forward and back motion.
Therefore, builders should be very careful in constructing an
engine truck, as it adds safety to a locomotive, and gives satisfaction
and comfort to the engineer.
QUESTION 9: Why is it that a lubricator will not feed
as regularly when working steam, as when the engine is drifting?
ANSWER: The trouble is that the openings in choke plugs are
too large, and they always grow larger as long as the lubricator
is used. To overcome this deficiency, open the shut-off plug just
above sight feeder, not more than one-half turn, or less, if sufficient.
You will find that it will feed just the same while working steam,
as when the engine is drifting. The reason why lubricators will
do this is because you have boiler pressure in the pipe that conveys
the oil to the steam chest. Engineers are often mistaken in making
their reports. When valve-strip springs break and the engineer
doesn't know how to locate it, sometime the machinist has to take
off both steam chest covers before the broken spring is located.
If an engineer will have his fireman stand on the steam chest
cover when he applies steam to the engine, he will feel the strip
when it strikes the friction plate, as the strip always drops
down when the spring is broken, and the steam shut off. Or, you
may put your ear against the steam chest, and when the engine
is given steam, you will hear the valve strip strike the friction
plate. So you need never make a mistake in reporting broken valve-strip
QUESTION 10: Why is it, when removing a pair of wheels
on account of skid flats, that one wheel sometimes has a flat
place two and one half or three inches, while the other wheel
on the same axle has a flat place only one half an inch, or less?
ANSWER: I have asked a great many men in charge of car works,
and they have invariably replied that one wheel has more chill
than the other. But this is not the case. It is because the rail
on the side where the wheel is flattened so badly is sanded, and
the other is not. Then both sand pipes should be kept open, so
that whenever sand is applied, both rails will get the benefit.
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