Joe Stupar asked about how the roof cables were wired. A picture is worth a thousand words. These diagrams essentially apply to all of the wood cars except the 36, which has only one electrical cabinet and a different interior lighting arrangement.
That is an interesting configuration and differs from the North Shore’s practice. With the 3ed Rail switch closed, the 3ed rail shoes would be hot when running on overhead trolley. The North Shore cars have a single pole double throw knife switch that will select the overhead trolley or 3ed rail but not both.
ReplyDeleteThis brings up an interesting question, did the CA&E operate with the buss jumper cables in place when running on the “L”? If they did, that could set up some interesting problems. It is my understanding that on the CTA, the 3ed rail gaps at a sub station circuit boundaries are longer than a normal car length so as a train passes through the gap the 2 circuits would not be momentarily bridged together. There is a good reason for this, if there is a fault on the circuit that the train is entering, you would not feed the fault through the car wiring. This is also important if maintenance work in going on and it would be a safety hazard to momentarily energize the circuit.
I have seen this happen on an overhead catenary system that used commutating (bridging) type section insulators. This section insulator was located at a crossover and one track was down for maintenance. The breakers had been racked out at the substations and the line crew had the protective grounds in place. A light rail train went through the crossover by mistake, the operator even ran over some safety cones in the process. Well, all hell broke loose when the pantograph bridged the two circuits! This caused major damage to the pantograph and to the section insulator. Fortunately the protective grounds did there job and no one got hurt.
Randy Anderson
Yes, this is also different from the wiring for the CA&E steel cars. On the wood cars I have removed the blade from the 3rd rail switch so the shoes cannot ever be energized.
ReplyDeleteThere was some discussion on the CA&E list about having bus jumpers in place while running on the L. Nobody can remember the train stopping long enough for the trainmen to remove or replace all the jumpers, so evidently the CA&E just got away with it.
That's an interesting story about shorting across an insulator to a dead section. Protective grounds are your friends. On the CA&E, the substations had semaphores that would be raised if one side was dead, so a train would not bridge the gap.
Hi Randall:
ReplyDeleteThanks for posting this diagram. Timing could not have been better. It gave me an idea of how things worked while we rehooked things up on 303. We were able to finish up yesterday(Saturday) and move her under her own power. As expected the first test showed some issues to correct, but she ran a short test run and will be a pleasure to run in the future.
Chris Chestnut
Always glad to be of help, Chris.
ReplyDeleteThat's the best use of Fermilab blueprint and diagram paper I've ever seen.
ReplyDeleteWouldn't light circuits #6, #7, & #8 be a little bright. Only one lamp in circuit?
ReplyDeleteThose ceiling fixtures have 5 bulbs each, so no problem.
ReplyDeleteHowever... what about the headlight?
I'll make some wiring diagrams to show the difference between North Shore and CA&E headlights when I get some time.
ReplyDeleteThe headlight has its own dropping resistor, on both CA&E and North Shore. The resistor on a CA&E car is sort of a thin square box hanging underneath, usually with big rust holes in the case. The circuits are different between NSL and CA&E though as you will see in the diagram when Randy posts it.
ReplyDelete