The prevent shuntThe prevent shunt of a Track Circuit is the value of resistance connected across the rails at which the track circuit Relay energises (that is, it just makes it... of a Track CircuitAn electrical device using the rails in an electric circuit, which detects the absence of trains on a defined section of line. is the value of resistance connected
across the rails at which the track circuitAn electrical device using the rails in an electric circuit, which detects the absence of trains on a defined section of line. RelayAn electro-mechanical switching device used in many types of Signalling Systems. energises (that is, it just
makes its front contacts).