REGISTER

Tony Godber CEng, BSc(Eng) MIET, MIRSE

Rio Tinto

To perform its safety critical functions, a signalling system for a rail network needs to have timely information on the position of trains and the occupancy status of track sections. This is essential to perform its primary function of preventing collisions and derailments.

The fundamental requirements of train detection systems are described, including proof of train absence for setting of points and operation of signals, proof of train presence for additional controls and updating of train position for network management and customer information purposes.

Existing technologies for track based train detection, including track circuits and axle counters, are then discussed, including many limitations on their use and application and associated safety risks. The and complications arising from the interface with other engineering disciplines, in particular the permanent way and traction power supplies are briefly explored. Consideration of train and communications based alternatives is then covered, including a discussion of whether this is the future for train detection.