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Items on CHART #4
ENGINE
There is no difference in the fundamental principles upon which the old and new style engines are designed.
The greatest difference is in the mechanical construction. Two very important items in connection with the care and
operation of any steam engine are, first, starting when cold; second, lubrication. In starting any steam engine when it
is cold the first steam admitted to the cylinders is condensed by the cold cylinder walls. Care must be taken not to
allow the engine to attain too much speed until the cylinder temperature is high enough to prevent condensation. This
water from the condensed steam must be given time to escape from the cylinders otherwise it may damage some of
the moving parts owing to the fact that it is incompressible and cannot escape quickly enough. This matter has been
taken care of in the new engines by the means of cylinder cocks, which should be opened when the engine is started
cold and allowed to remain open until the engine is turning freely. On the older types the usual procedure is to open
the throttle before the steam pressure rises too high. The engine should be kept simpled and the reverse lever changed
back and forth from reverse position to go ahead. By keeping the engine simpled double the amount of ports for water
to escape are provided than would be if the engine were starting compound. When the piston reaches the end of the
stroke and there is water in the end of the cylinders it will be released into exhaust if the reverse lever is thrown to the
opposite position. It is a good rule to allow the engine to run simple until steam emerges from the over flow pipe on
the condenser. This assures that all the water is out of the cylinders, and that steam is coming from exhaust.
STEAM VIBRATION
Vibration is the effect of anything which may cause the turning moment or torque of the engine to be
perceptible from the seat of the car. Instead of pulling smoothly, as a steam engine should it shakes the car. Vibration
has been divided into two heads in order to be able to diagnose and locate the trouble by elimination.
ENGINE VIBRATES WHEN COMPOUND
A compound engine is one in which the steam does part of its expansion in one cylinder, then passes on to
another where this expansion is completed. The exhaust from the high pressure Is used to feed the low pressure. If by
any means the steam can escape without doing full work in the low pressure cylinder or it can get to the low pressure
cylinder without doing its full amount of work in the high pressure cylinder it will have a tendency to cause one
cylinder to do more work than the other. This will unbalance the engine causing it to pull in a jerky manner. If the
engine vibrates when running compound, but does not when running simpled the chances are that the steam is by
some means getting to the low pressure cylinder without having done its work in the high pressure cylinder.
There are three valves on the top of the engine, which are designated on the chart as simpling valves. Two of
these are known as poppet valves, the other one the pass-over valve (old style engine.) When the engine is simpled the
pass-over valve is opened allowing the steam direct from the generator to pass through to the low-pressure steam
chest; the high-pressure poppet valve opens allowing the exhaust from the high-pressure cylinder to escape directly to
the condenser. The low-pressure poppet valve should seat closing the passage between the high-pressure exhaust and
the low-pressure steam chest. Under this condition we have two cylinders working independent of each other. Each
receives its steam from the generator and each exhausts into the condenser. When the simpling pedal is allowed to rise
the engine changes from simple to compound. The pass-over valve closes, the high pressure poppet valve also closes
and cuts off the high pressure exhaust from the condenser, causing it to pass through the low pressure poppet valve
(which is now open) into the low pressure steam chest. This rather lengthy statement is for the purpose of conveying
the idea of where the steam should go when engine is simpled and where it should go when engine is compounded.
Thus, we see in running compound if the pass-over valve is leaking or binding, so that it does not seat, the engine is
trying to run partly compounded and partly simpled at the same time. The steam which leaks through the pass-over
valve may cause back pressure on the low pressure piston and also it will cause the low pressure cylinder to do more
than its share of the work, thus destroying the balance between the two.
If the high-pressure poppet valve leaks or does not seat the exhaust from the high-pressure cylinder will
escape into the condenser instead of finishing its work through the low-pressure cylinder. This will rob the low-
pressure cylinder of its full share of the steam and destroy the balance. A good way to test the high-pressure poppet
valve to see if it is seated is to turn this stem with a pair of pliers if the simpling mechanism is in compound position.
If it is not seated it will turn easily, but if it is seated properly it will not turn, without applying considerable force.
A sand flaw in the cylinders might allow the steam to short circuit over-loading the low-pressure cylinder.
This is a condition of which but two cases have come to our knowledge. It is mentioned merely as a last extremity.
All the cylinders are thoroughly inspected and tested before leaving the factory. However, a very slow leak or flaw,
