Point chain

The turnout chain is a device on an electrical interlocking which, after issuing a command to set the route , automatically brings all turnouts , crossings and track barriers in the route and slip path as well as edge protection into the correct position. Since the electrical point machines require the most energy at the beginning of a changeover process due to the starting current, they start up at intervals of 0.25 seconds. This is to avoid overloading the energy supply.

The operator can lock the turnout chain. In this way, the switching of the switches caused by the route can be prevented in a signal box. However, it is still possible to switch points individually. The blocking of the turnout chain is necessary for security against some auxiliary operations and is monitored by the interlocking for most designs.

In the track diagram interlockings of the former Deutsche Reichsbahn , this facility is known as turnout self-running .

literature

• Walter Jonas. Using electronic interlockings - The regular operation , page 101. Eisenbahn-Fachverlag 2001. ISBN 3-9808002-0-2