Ground installations
Railway traction - Equipment operation and safety

In addition to the signposts along the line, the track itself is the main medium for transmitting information between the vehicle and the control center.

• Transmission of timely information

  The simplest devices include :

  • an electrical contact between a fixed pad placed between the two rail wires (known in France as a "crocodile") and a brush carried by the vehicle, used to repeat the crossed signal on board;

  • a pedal located in line with the rail and activated by the passing wheel, giving the train's position for announcing and closing level-crossing gates.

  In the case of more advanced point information, electromagnetic beacons positioned between the two rails emit a magnetic...