A Unique Application of the Wheatstone Bridge to High-Speed Train Braking

This paper describes a method for indicating to the locomotive engineman the condition of the circuits controlling the electropneumatic brakes which are now in widespread use on high-speed passenger trains. The apparatus consists of a Wheatstone bridge so arranged as to insure the operation of the bridge itself as well as to indicate the condition of the electropneumatic brake circuits. Calibrated dials indicate the number of vehicles in the train. This equipment is proving to be a useful tool in making terminal tests, and assist in determining the location of any change of resistance of the train line wire circuits which may occur. It also provides a convenient means for indicating to the engineman while en route, any change which may occur in the train line circuits. All parts of the equipment are designed to provide the ruggedness essential for long life on locomotives.