_RUNNING A FAST FREIGHT TRAIN._
RUNNING FREIGHT TRAINS.
By far the greater proportion of American locomotive engineers are
employed on freight service. On most roads, the freight engines
constitute from seventy-five to ninety per cent of the whole locomotive
equipment. On this kind of service, locomotive engineers learn their
business by years of hard practice in getting trains over the road
as nearly as possible on time. On the best of roads, there is much
hardship to be undergone, working ahead through every discouragement
of bad weather or hard-steaming engines. The man who brings the most
energy, good sense, and perseverance to his aid, will come out most
successfully above these difficulties.
Every department of locomotive engine running has difficulties peculiar
to itself. Every kind of train needs to be handled understandingly, to
show the best results; but, I think, getting a heavy fast freight train
on time, over a hilly road, having a single track, requires the highest
degree of locomotive engineering skill. Therefore, I have selected that
form of train as the first subject of description.
THE ENGINE.
The engine that takes the train over the road weighs 35 tons, and has
1,100 square feet of heating-surface for generating steam for cylinders
17 by 24 inches, which, through the pistons, transmit power to wheels
60 inches diameter. The engine is an ordinary eight-wheeled bituminous
coal-burning American type of locomotive, built by one of our best
makers, and well adapted for pulling any kind of train over a Western
railroad.
THE TRAIN.
This consists of 20 loaded cars, making an aggregate weight of 450 tons.
THE DIVISION.
The physical character of the country, which is rolling prairie,
makes the road undulatory,--up hill, then down grade, with occasional
stretches of level track. Some of the gradients rise to sixty feet
to the mile, extending over two miles without sagging a foot. Sound
steel rails, well tied, are supported by a graveled road-bed, making
an excellent track, and presenting a good opportunity for fast running
where high speed is needed. The train is run on card-time, stopping
about every twelve miles. Like all other Western roads, the stations
are unprotected by signals; and the safety of trains is secured mostly
by vigilance on the part of the engineer and other train-men.
PULLING OUT.
When the engineer gets the signal to go, he drops the reverse lever
into the full forward notch, gives the engine steam gently, with due
care to avoid breaking couplings, and pulls the sand-lever. A slight
sprinkling of sand only is dropped on the rails, which keeps the engine
from slipping while getting the train under way. A clear, level fire
is burning over the grates before the start is made, and this suffices
till the most crowded switches are passed: so, when the signal to start
is given, the fireman closes the fire-door, and opens the damper; these
duties not preventing him from keeping a lookout for signals.
HOOKING BACK THE LINKS.
As the engine gets the train into motion, the engineer gradually hooks
up the links. This is not done by a sudden jerk as soon as the engine
will move, with the steam cutting off short. He waits for that till the
train is well under the control of the engine, hooking up gradually.
Some men think that it is best to get the valves up to short travel as
soon as possible, without reflecting that it is better for the motion
to let the engine be going freely before hooking up short. I have
often seen men coming into terminal stations with a heavy fire and the
safety-valves blowing, and the engine toiling slowly along with the
links hooked up to eight inches cut. In cases of this kind, a runner
may better work the engine well down, so that the valve will travel
freely over the seat. By doing so when the engine is working slow
and heavy, there will be less wear to the valves, and less danger of
breaking a valve yoke. It is only in cases where there is an advantage
in saving steam, that benefit is derived from working the engine close
hooked back. There is a right time for all things, and working steam
expansively is no exception to the rule.
WORKING THE STEAM EXPANSIVELY.
At the right time, our engineer gets the reverse lever notched up;
for he knows, that to obtain the greatest amount of work out of the
engine, with the least possible expenditure of fuel, the links must be
hooked back as far as can be done consistently with making the required
speed. Some engines will not steam freely when run close back if they
are burning coal that needs a strong draught. This is the exception,
however, and most engines will steam best in this position; and many of
those that fail to steam well cutting off short are not properly fired,
or the draught appliances need adjusting. Most firemen who run with a
heavy fire fail worst with engines that steam indifferently when hooked
up. Engineers should give this their attention, and do every thing
possible to make the engine steam while working with the lever as near
the center notch as can be done while handling the train.
ADVANTAGE OF CUTTING OFF SHORT.
When the links are notched close towards the center, the travel of the
valves is so short that they close the steam-ports shortly after the
beginning of the stroke, at six, nine, or twelve inches of the piston’s
travel, as the case may be, permitting the steam to push the piston
along the remainder of the stroke by its expansive power. Steam at a
high pressure is as full of potential energy as a compressed spiral
spring, and is equally ready to stretch itself out when the closing
of the port imprisons it inside the cylinder; and, by this act of
expanding, it exerts immense useful energy, which would escape into
the smoke-stack unutilized if the cylinders were left in communication
with the boiler till the release took place. Suppose, for instance,
that a boiler pressure of ten tons is exerted upon the piston from the
beginning to the middle of the stroke, and is then cut off. During the
remainder of the stroke, the steam will continue to press upon the
piston with a regularly diminishing force, till, at the end of the
stroke, if release does not take place earlier, it will still have
a pressure of five tons. The work performed by the steam during the
latter part of the stroke is pure gain, due to its expansive principle.
If the steam is cut off earlier, at a third or fourth of the piston
travel, the gain will be correspondingly great. With the slide-valve
link-motion used on locomotives, the steam can not be held to the end
of the stroke; but the principle of expansion holds good during the
period the steam is held in the cylinders after the cut-off.
The observing engineer of any experience does not require to have
the advantages of working his engine expansively impressed upon his
attention. His fuel-record has done that more eloquently than pen can
write.
BOILER PRESSURE BEST FOR ECONOMICAL WORKING.
There is a close and constant relation between the boiler pressure
carried, and the useful work obtained from expansion of steam. The
higher the pressure, the greater elasticity the steam possesses. The
tendency of modern steam engineering is, to employ intensely high
boiler pressure, expanding the steam by means of excellent valve-gear
in steam-jacketed cylinders, so that it is reduced to low tension
before escaping into the atmosphere, or into the condenser, as the
case may be. Wonderfully economical results have been obtained in this
manner,--results which can never be approached in locomotive practice
while the ordinary slide-valve is used. But, while we can not hope to
rival the record of high-class automatic cut-off engines, their methods
can teach us useful lessons.
It is advisable to keep the steam constantly close to the blowing-off
point. During a day’s trip, considerably less water will be evaporated
when a tension of 140 pounds is carried, than will be required
with a pressure of 100 pounds or under. And, where less water is
evaporated, a smaller quantity of fuel will be consumed in doing
the work. Running with a low head of steam is a wasteful practice,
for several good reasons. The comparatively light pressure upon the
surface of the water allows the steam to pass over damp, or mixed
with a light watery spray, which diminishes its energy; since the
wet steam contains less expansive medium than dry steam. It requires
nearly the same expenditure of fuel to evaporate water at the pressure
of the atmosphere alone, that it does to make steam at the higher
working tensions: consequently, the work obtained by the expansion of
the high-pressed steam is clear gain over the results to be obtained
by working at a low pressure. This is a very important principle in
economical steam engineering. Engineers who are accustomed to making
long runs between water-tanks, when every gallon is needed to carry
them through, know that their sure method of getting over the dry
division successfully, is to carry steam close to the popping-point,
pull the throttle wide open, hug the links close to the center, and see
that no loss occurs through the safety-valves.
RUNNING WITH LOW STEAM.
There are engineers who habitually carry merely sufficient steam to get
them along on time, under the mistaken belief that they are working
economically. John Brown runs steadily, and takes as good care of his
engine as any man on the A. & B. road; but he dislikes to hear the
steam escaping from the safety-valves, and prevents it from doing so by
habitually using steam thirty pounds below the blowing-pressure. The
consequence is, that he always makes a bad record on the coal-list,
compared with the other passenger men.
THE THROTTLE-LEVER.
In the interest of economy, the throttle-lever should be kept wide
open when practicable, and the speed regulated by the reverse-lever.
Experiments with the indicator have demonstrated beyond a doubt,
that running with the throttle-valve partly closed, wire-draws the
steam before it reaches the cylinders, whereby the initial pressure
is materially reduced, and its power for expansive work seriously
diminished.
MANAGEMENT OF THE FIRE.
The engine has moved only a few rods from the depot when the steam
shows indications of blowing off; and then the fireman sets to
work,--not to pile a heap of coal indiscriminately into the fire-box.
That is the style of the dunce whose natural avocation is grubbing
stumps. Ours is a model train, and a model fireman furnishes the
power to keep it going. He throws in four or five shovelfuls at each
firing, scattering the coal along the sides of the fire-box, shooting
a shower close to the flue-sheet, and dropping the required quantity
under the door. With the quick intuition of a man thoroughly master of
his business, our model fireman perceives at a glance, on opening the
door, where the thinnest spots are; and they are promptly bedded over.
The glowing, incandescent mass of fire, which shines with a blinding
light that rivals the sun’s rays, dazzles the eyes of the novice,
who sees in the fire-box only a chaotic gleam; but the experienced
fireman looks into the resplendent glare, and reads its needs or its
perfections. The fire is maintained nearly level; but the coal is
supplied so that the sides and corners are well filled, for there the
liability to drawing air is most imminent. With this system closely
followed, there is no difficulty experienced in keeping up a steady
head of steam. But constant attention must be bestowed upon his work
by the fireman. From the time he reaches the engine, until the hostler
takes charge at the end of the journey, he attends to his work, and to
that alone; and by this means he has earned the reputation of being
one of the best firemen on the road. His rule is, to keep the fire up
equal to the work the engine has to do, never letting it run low before
being replenished, never throwing in more coal than the keeping up of
steam calls for. The coal is broken up moderately fine, a full supply
being prepared before the fire-door is opened; and every shovelful
is scattered in a thin shower over the fire,--never pitched down on
one spot. Some men never acquire the art of scattering the coal as it
leaves the shovel; and, as a result, they never succeed in making an
engine steam regularly. Their fire consists of a series of coal-heaps.
Under these heaps, clinkers are prematurely formed; and between them
spaces are created, through which cold air comes, and rushes straight
for the flues, without assimilating with the gases of combustion, as
every breath of air which enters the fire-box ought to do.
CONDITIONS THAT DEMAND GOOD FIRING.
Roads that are hilly require far more skillful management to get a
train along than is called for on level roads, and the greater part of
the extra dexterity is needed from the fireman. To get a heavy train up
a steep hill, it is generally run at a high speed before reaching the
grade, so that the momentum of the train can be utilized in climbing
the ascent. Running for a hill is a particularly trying time on the
fireman; for the engine is rushing at a high speed, and often working
heavily. This ordeal must be prepared for in advance, by having the
fire well made up, and kept at its heaviest by frequent firing. When
the engine gets right on to the grade, toiling up with decreasing
speed, every pound of steam is needed to save doubling, and steady
watchfulness is required to prevent a relapse of steam; but the danger
of the engine “turning” the fire is not nearly so great as it was when
running fast for the hill.
HIGHEST TYPE OF FIREMAN.
The highest type of fireman is one, who, with the smallest quantity
of fuel, can keep up a good head of steam without wasting any by the
safety-valves. He endeavors to strike this mean of success by keeping
an even fire; but it sometimes happens, that the closest care will not
prevent the steam from showing indications of blowing off. When this is
the case, he keeps it back by closing the dampers, or, if that is not
sufficient, opens the door a few inches. Immense harm is done to flues
and fire-boxes by injudicious firing.
SCIENTIFIC METHODS OF GOOD FIREMEN.
It is not necessary that a man should be deeply read in natural
philosophy, to understand intimately what are actually the scientific
laws of the business of firing. Mr. Lothian Bell, the eminent
metallurgist, somewhere expresses high admiration for the exact
scientific methods attained in their work by illiterate puddlers.
Although they knew nothing about chemical combinations or processes,
they manipulated the molten mass so that, with the least possible
labor, the iron was separated from its impurities. In a similar way,
firemen skillful in their calling have, by a process of induction,
learned the fundamental principles of heat-development. By experiments,
carefully made, they perceive how the greatest head of steam can
be kept up with the smallest cargo of coal; and they push their
perceptions into daily practice.
If an accomplished scientist were to ride on the engine, observing the
operations of a first-class fireman, he would find that nearly all the
carbon of the coal combined with its natural quantity of oxygen to
produce carbon dioxide, thereby giving forth its greatest heat-power;
and that the hydro-carbons, the volatile gases of the coal, performed
their share of calorific duty by burning with an intensely hot flame.
He would find that these hydro-carbon gases, although productive of
high-power duty when properly consumed, were ticklish to manage just
right, for they would pass through the flues without producing flame
if they were not fully supplied with air; and, if the supply of air
were too liberal, it would reduce the temperature of the fire-box below
the igniting-point for these gases, which is higher than red-hot iron,
and they would then escape in the form of worthless smoke. Our model
fireman manages to consume these gases as thoroughly as they can be
consumed in a locomotive fire-box.
THE MEDIUM FIREMAN.
John Barton is considered a first-class fireman by some men. He works
hard to keep up steam, and is never satisfied unless the safety valves
are screaming. He carries a heavy fire all the time; and, when the
pop-valves rise, he pulls the door open till they subside, gets in a
few shovelfuls more coal, closes the door till the steam blows off
again, and repeats the operation of throwing open the door. This man
has learned only the half of his business. He has got through his
head how to keep up steam, but he has not acquired the more delicate
operation of keeping it down wisely and well. Training with an
intelligent engineer anxious to make a good fuel-record, will, in a few
months, improve Barton wonderfully. Barton is the medium fireman.
THE HOPELESSLY BAD FIREMAN.
Behind him comes Tom Jackson, the man of indiscriminately heavy
firing. Tom’s sole aim is to get over the road with the least possible
expenditure of personal exertion. He tumbles in a fire as if he were
loading a wagon, the size of the door being his sole gauge for the
lumps. When the fire-box is filled to the neighborhood of the door,
he climbs up on the seat, and reclines there till the steam begins to
go back through drawing air: then he gets down again, and repeats the
filling-up process, intent only on getting upon the seat-box with as
little delay as possible. His firing is regulated by the appearance
of the smoke issuing from the stack. So long as it continues of
murky blackness, he reclines in happiness: when the first streaks of
transparency appear in the smoke, he becomes unhappy, but gets up, and
suppresses smoke-consumption by smothering the flames with green coal.
If by any chance the engine steams so freely that the safety-valves
blow, the door is jerked wide open, and kept there till she cools down.
So the round goes. A hot, scorching fire, which heats the sheets and
flues to their highest temperature, is continually being interrupted
by the sudden cooling from a heavy load of damp coal, or a chilling
current of cold air. No wonder, that, with such treatment, leaky flues,
weeping stay-bolts, and pouring mud-rings, make their own protests,
often reiterated on the pages of round-house work-books.
WHO IS TO BLAME FOR BAD FIRING?
The destruction inflicted upon the heating-surface of locomotives by
the changes of temperature due to bad firing, should be charged to the
engineer. The fireman commits the havoc, but the engineer is more to
blame for allowing it to be done. Engineers often permit firemen to do
their work badly rather than have words about it. But this is mistaken
policy. A little firmness in the start will convince the worst of
firemen that they must strive to fire properly, or quit; and a man who
is indisposed to do his work well, deserves his walking-papers without
delay. There is no kindness in retaining a hopelessly bad fireman on an
engine. As a fireman, he is a continual loss to his employers; he is no
credit to his fellow-workmen; and if, by the mistaken forbearance of
engineers, he ever reaches the right-hand side, he will be a reproach
to the engineering fraternity.