A. Would test for a broken circuit or open circuit: First, by placing a carbon across the binding posts at dynamo. If the trouble was in the dynamo, no flash would be seen, but if dynamo was all right you would get a flash; this would indicate that the trouble was on towards the lamp. Second: Go to the lamp, place your carbon across binding posts. If wire was broken between dynamo and lamp you would not get a flash. If your wires were all right you would get a flash and you would find your trouble in the lamp. No doubt, it would be a burned-out carbon.
64. Q. How would you proceed to locate the point of trouble with a short circuit?
A. Would remove (1) one of the lead wires from the binding post at dynamo; if trouble was in dynamo you would not note any difference in action of speed. (2) Would disconnect one of the cab wires; if the trouble is in cab circuit, speed would increase and lamp would burn. (3) If trouble is not in cab circuit, would go to lamp, disconnect one of the main wires from binding post; if short circuit is in the wires between dynamo and lamp, there would be no change in speed of dynamo, but if the wires are O. K. the speed of engine would increase and your trouble would be in the lamp.
DUPLEX LOCOMOTIVE STOKER
1. Q. Of what does the driving mechanism of a Duplex Locomotive Stoker consist?
A. It consists of a steam cylinder with reverse head and valve arrangement similar to the steam end of an eleven inch Westinghouse air pump.
2. Q. How is the power controlled?
A. The speed is variable, and by turning the valve controlling the engine steam inlet, can be made greater or less according to the amount of coal needed.