Controlling Le Shuttle: signalling for the Channel Tunnel

Railway signalling systems have three main functions: train separation; conflict prevention; and monitoring and control. To these three fundamental functions, most modern systems add a fourth, known as automatic train protection (ATP). This is a system on board the train, which monitors the train speed and applies the brake automatically if the train exceeds the safe speed, which is determined by line conditions, the state of the signals etc. The Channel Tunnel will be equipped with such a system. Train separation and ATP are carried out by a computer-based system known as TVM 430. The author describes the system and its operation