Supervision and Operation of Mass Transit Systems

Supervision of operation of a mass transit railway is not just about the signalman but about meeting the overall requirement to run a high frequency train service efficiently. This requires a good fundamental understanding of how the Signal & Control Systems fit within the overall Railway Control System, where they need to be integrated and where segregation is required. Supervisory and control systems have developed on the railways in a manner which has sought to more efficiently control the safety critical signalling systems and to provide enhanced communications to deal with service perturbations. A clear distinction, involving physical segregation, was made right from the start of the introduction of automatic routing between the control system and the signal system itself. A further fundamental philosophy was to ensure that segregation occurred between the primary means of authorising train movement (the signalling) and the secondary means (e.g. train radio) which provided a diverse foundation from which to build an overall supervisory system of a high integrity.