A. Yes. Because the separate exhaust valve is opened by air pressure and the engine cannot be simpled without sufficient pressure.
19. Q. How are the blows in a compound located?
A. The same as in a simple engine with the exception that any blow on the high-pressure side will not be heard when the separate exhaust valve is closed. A blow on the high-pressure side will increase the pressure in the low-pressure side, so relief valves will pop on low-pressure side when working compound with full throttle.
20. Q. What should be done if high-pressure piston of a cross compound is broken off the rod, or if the high-pressure or low-pressure cylinder head is broken?
A. Cover the ports on that side, open separate exhaust valve and run in; use live steam in low-pressure cylinder only, for the broken piston. With broken cylinder head, would cover ports on that side. Open separate exhaust and run in with low-pressure side. Would not take down main rod, but would take out pop valves in both cylinder heads and see that the cylinder is properly oiled. For low-pressure head broken, would cover ports on that side, open separate exhaust valve and use high-pressure side; need not take down main rod, but would see that the cylinder is well oiled.
21. Q. In the event of separate exhaust valves failing to work when throttle is wide open, what can be done to assist in opening?
A. Ease throttle off very fine to reduce the receiver pressure; in a moment or two the separate exhaust valve should then move. If this did not work, would shut off entirely, even at the risk of stalling, as in that event the train could be started again with engine cut in simple.
22. Q. If a transmission bar on a cross compound is broken, what would you do for the right side? For the left side?
A. For right side would cover ports on that side, take out pop from cylinder head, open separate exhaust and run in with other cylinder. For left side, cover ports and fasten valve stem same as for right side. Would leave main rods up, keep separate exhaust open in both cases and see that cylinder is well oiled.
23. Q. In the event of a cross compound beginning to jerk badly and cylinder head pops in low-pressure cylinder popping, where would you look for the trouble?