Operation
Properly the bow collector should be mounted in such a way so that the top edge of the collector plate would rise several inches above the wire when the collector frame is standing straight up. Thus the collector usually leans opposite to the direction of travel; when the time comes to travel in the opposite direction, the collector must be swung over. To allow this to happen, the overhead wire must be raised by several inches at places where the bows are swung over, such as terminals and turn-outs. This operation is usually achieved by ropes and pulleys. The collector is folded down to a horizontal position when the car is not in use.
Some early cars had no means to swing the bows over. It was thought that this would happen automatically when the tramcar started travelling the other way, but collectors such as these were a failure.
Most Soviet trams (of which some are still in use in ex-USSR) had no means to swing the bows over. These trams were not designed to travel two ways. Another example is KTV-55-2 tramcar which had two bow collectors for the two directions of travelling.
Read more about this topic: Bow Collector
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