Token key machine

This is the token key machine. The signalman pulls the key up into the top position, presses the knob in several times, which sends a signal to the train driver, who in return sends a signal back which allows the signalman to release the key which is then taken out and handed to the train driver. The train can’t leave without being given the key, which the train driver then has to hand to the signalman and the end of the line. The process is then repeated for the return journey.

Done