You may know all about an engine. You may be able to build one, and yet
run a traction in the ditch the first jump.
It is a fact that some men never can become good operators of a traction
engine, and I can't give you the reason why any more than you can tell
why one man can handle a pair of horses better than another man who has
had the same advantages. And yet if you do ditch your engine a few
times, don't conclude that you can never handle a traction.
If you are going to run a traction engine I would advise you to use your
best efforts to become an expert at it. For the expert will hook up to
his load and get out of the neighborhood while the awkward fellow is
getting his engine around ready to hook up.
The expert will line up to the separator the first time, while the other
fellow will back and twist around for half an hour, and then not have a
good job.
Now don't make the fatal mistake of thinking that the fellow is an
expert who jumps up on his engine and jerks the throttle open and yanks
it around backward and forward, reversing with a snap, and makes it
stand-up on its hind wheels.
If you want to be an expert you must begin with the throttle, therein
lies the secret of the real expert. He feels the power of his engine
through the throttle. He opens it just enough to do what he wants it to
do. He therefore has complete control of his engine. The fellow who
backs his engine up to the separator with an open throttle and must
reverse it to keep from running into and breaking something, is running
his engine on his muscle and is entitled to small pay.
The expert brings his engine back under full control, and stops it
exactly where he wants it. He handles his engine with his head and
should be paid accordingly. He never makes a false move, loses no time,
breaks nothing, makes no unnecessary noise, does not get the water all
stirred up in the boiler, hooks up and moves out in the same quiet
manner, and the onlookers think he could pull two such loads, and say he
has a great engine, while the engineer of muscle would back up and jerk
his engine around a half dozen times before he could make the coupling,
then with a jerk and a snort he yanks the separator out of the holes,
and the onlookers think he has about all he can pull.
Now these are facts, and they cannot be put too strong, and if you are
going to depend on your muscle to run your engine, don't ask any more
money than you would get at any other day labor.
You are not expected to become an expert all at once. Three things are
essential to be able to handle a traction engine as it should be
handled.
First, a thorough knowledge of the throttle. I don't mean that you
should simply know how to pull it open and shut it. Any boy can do that.
But I mean that you should be a good judge of the amount of power it
will require to do what you may wish to do, and then give it the amount
of throttle that it will require and no more. To illustrate this I will
give an instance.
An expert was called a long distance to see an engine that the operator
said would not pull its load over the hills he had to travel.
The first pull he had to make after the expert arrived was up the worst
hill he had. When he approached the grade he threw off the governor
belt, opened the throttle as wide as he could get it, and made a run for
the hill. The result was, that he lifted the water and choked the
engine down before he was half way up. He stepped off with the remark,
"That is the way the thing does." The expert then locked the hind wheels
of the separator with a timber, and without raising the pressure a
pound, pulled it over the hill. He gave it just throttle enough to pull
the load, and made no effort to hurry ii, and still had power to spare.
A locomotive engineer makes a run for a hill in order that the momentum
of his train will help carry him over. It is not so with a traction and
its load; the momentum that you get don't push very hard.
The engineer who don't know how to throttle his engine never knows what
it will do, and therefore has but little confidence in it; while the
engineer who has a thorough knowledge of the throttle and uses it,
always has power to spare and has perfect confidence in his engine. He
knows exactly what he can do and what he cannot do.
The second thing for you to know is to get onto the tricks of the steer
wheel. This will come to you naturally, and it is not necessary for me
to spend much time on it. All new beginners make the mistakes of turning
the wheel too often. Remember this-that every extra turn to the right
requires two turns to the left, and every extra turn to the left
requires two more to the right; especially is this the care if your
engine is fast on the road.
The third thing for you to learn, is to keep your eyes on the front
wheels of your engine, and not be looking back to see if your load in
coming.
In making a difficult turn you will find it very much to your advantage
to go slow, as it gives you much better control of your front wheels,
and it is not a bad plan for a beginner to continue to go slow till he
has perfect confidence in his ability to handle the steer wheel as it
may keep you out of some bad scrapes.
How about getting into a hole? Well, you are not interested half as
much in knowing how to get into a hole as You are in knowing how to get
out. An engineer never shows the stuff he is made of to such good
advantage as when he gets into a hole; and he is sure to get there, for
one of the traits of a traction engine is its natural ability to find a
soft place in the ground.
Head work will get you out of a bad place quicker than all the steam you
can get in your boiler. Never allow the drivers to turn without doing
some good. If you are in a hole, and you are able to turn your wheels,
you are not stuck; but don't allow your wheels to slip, it only lets you
in deeper. If your wheels can't get a footing, you want to give them
something to hold to. Most smart engineers will tell you that the best
thing is a heavy chain. That is true. So are gold dollars the best
things to buy bread with, but you have not always got the gold dollars,
neither have you always got the chain. Old hay or straw is a good
thing; old rails or timber of any kind. The engineer with a head spends
more time trying to give his wheels a hold than he does trying to pull
out, while the one without a head spends more time trying to pull out
than he does trying to secure a footing, and the result is, that the
first fellow generally gets out the first attempt, while the other
fellow is lucky if he gets out the first half day.
If you have one wheel perfectly secure, don't spoil it by starting your
engine till you have the other just as secure.
If you get into a place where your engine is unable to turn its wheels,
then your are stuck, and the only thing for you to do is to lighten your
load or dig out. But under all circumstances your engine should be
given the benefit of your judgment.
All traction engines to be practical must of a necessity, be reversible.
To accomplish this, the link with the double eccentric is the one most
generally used, although various other devices are used with more or
less success. As they all accomplish the same purpose it is not
necessary for us to discuss the merits or demerits of either.
The main object is to enable the operator to run his engine either
backward or forward at will, but the link is also a great cause of
economy, as it enables the engineer to use the steam more or less
expansively, as he may use more or less power, and, especially is this
true, while the engine is on the road, as the power required may vary in
going a short distance, anywhere from nothing in going down hill, to the
full power of your engine in going up.
By using steam expansively, we mean the cutting off of the steam from
the cylinder, when the piston has traveled a certain part of its stroke.
The earlier in the stroke this is accomplished the more benefit you get
of the expansive force of the steam.
The reverse on traction engines is usually arranged to cut off at I/4,
I/2 or 3/4. To illustrate what is meant by "cutting off" at I/4, I/2 or
3/4, we will suppose the engine has a I2 inch stroke. The piston begins
its stroke at the end of cylinder, and is driven by live steam through
an open port, 3 inches or one quarter of the stroke, when the port is
closed by the valve shutting the steam from the cylinder, and the piston
is driven the remaining 9 inches of its stroke by the expansive force of
the steam. By cutting off at I/2 we mean that the piston is driven half
its stroke or 6 inches by live steam, and by the expansion of the steam
the remaining 6 inches; by 3/4 we mean that live steam is used 9 inches
before cutting off, and expansively the remaining 3 inches of stroke.
Here is something for you to remember: "The earlier in the stroke you
cut off the greater the economy, but less the power; the later you cut
off the less the economy and greater the power."
Suppose we go into this a little farther. If you are carrying I00
pounds pressure and cut off at I/4, you can readily see the economy of
fuel and water, for the steam is only allowed to enter the cylinder
during I/4 of its stroke; but by reason of this, you only get an average
pressure on the piston head of 59 pounds throughout the stroke. But if
this is sufficient to do the work, why not take advantage of it and
thereby save your fuel and water? Now, with the same pressure as before,
and cutting off at I/2, you have an average pressure on piston head of
84 pounds, a loss of 50 per cent in economy and a gain of 42 per cent in
power. Cutting of at 3/4 gives you an average pressure of 96 pounds
throughout the stroke. A loss on cutting off at I/4 of 75 per cent in
economy, and a gain of nearly 63 per cent in power. This shows that the
most available point at which to work steam expansively is at I/4, as
the percentage of increase of power does not equal the percentage of
loss in economy. The nearer you bring the reverse lever to center of
quadrant, the earlier will the valve cut the steam and the less will be
the average pressure, while the farther away from the center the later
in the stroke will the valve cut the steam, and the greater the average
pressure, and, consequently, the greater the power. We have seen
engineers drop the reverse back in the last notch in order to make a
hard pull, and were unable to tell why they did so.
Now, as far as doing the work is concerned, it is not absolutely
necessary that you know this; but if you do know it, you are more likely
to profit by it and thereby get the best results out of your engine.
And as this is our object, we want you to know it, and be benefitted by
the knowledge. Suppose you are on the road with your engine and load,
and you have a stretch of nice road. You are carrying a good head of
steam and running with lever back in the corner or lower notch. Now
your engine will travel along its regular speed, and say you run a mile
this way and fire twice in making it. You now ought to be able to turn
around and go back on the same road with one fire by simply hooking the
lever up as short as it will allow to do the work. Your engine will
make the same time with half the fuel and water, simply because you
utilize the expansive force of the steam instead of using the live steam
from boiler. A great many good engines are condemned and said to use
too much fuel, and all because the engineer takes no pains to utilize
the steam to the best advantage.
I have already advised you to carry a "high pressure;" by a high
pressure I mean any where from I00 to I25 lbs. I have done this
expecting you to use the steam expansively whenever possible, and the
expansive force of steam increases very rapidly after you have reached
70 lbs. Steam at 80 lbs. used expansively will do nine times the work
of steam at 25 lbs. Note the difference. Pressure 3 I-5 times greater.
Work performed, 9 times greater. I give you these facts trusting that
you will take advantage of them, and if your engine at I00 or I00 lbs.
will do your work cutting off at I/4, don't allow it to cut off at I/2.
If cutting off at I/2 will do the work, don't allow it to cut off at
3/4, and the result will be that you will do the work with the least
possible amount of fuel, and no one will have any reason to find fault
with you or your engine.
Now we have given you the three points which are absolutely necessary to
the successful handling of a traction engine, We went through it with
you when running as a stationary; then we gave you the pointers-to be
observed when running as a traction or road engine. We have also given
you hints on economy, and if you do not already know too much to follow
our advice, you can go into the field with an engine and have no fears
as to the results.
How about bad bridges?
Well, a bad bridge is a bad thing, and you cannot be too careful. When
you have questionable bridges to cross over, you should provide yourself
with good hard-wood planks. If you can have them sawed to order have
them 3 inches in the center and tapering to 2 inches at the ends. You
should have two of these about 16 feet long, and two 2x12 planks about 8
feet long. The short ones for culverts, and for helping with the longer
ones in crossing longer bridges.
An engine should never be allowed to drop from a set of planks down onto
the floor of bridge. This is why I advocate four planks. Don't
hesitate to use the plank. You had better plank a dozen bridges that
don't need it than to attempt to cross one that does need it. You will
also find it very convenient to carry at least 50 feet of good heavy
rope. Don't attempt to pull across a doubtful bridge with the separator
or tank hooked directly to the engine. It is dangerous. Here is where
you want the rope. An engine should be run across a bad bridge very
slowly and carefully, and not allowed to jerk. In extreme cases it is
better to run across by hand; don't do this but once; get after the road
supervisors.