techincal

A fail-safe compressed air system operates one of the 3 braking systems. Two large steel weights act to keep brake shoes applied to the two 4 ft diameter brake drums. Compressed air at a pressure of between 50 and 100 p.s.i. operates 2 vertical pneumatic rams, which act against the weights to remove the brake. As the driver releases the brake, the cylinders lift the weights from the brake drums, allowing the cars to be moved. In the event of a compressed air failure, the brakes would simply be reapplied by the weights.