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 unnecessary 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.

=Compound locomotives=

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 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.