This is a safeguard found in some signalboxes for use when signalling a train onto occupied track, e.g. for a loco joining to carriages, multiple units joining together, or platform sharing. The route is set as normal onto the occupied track; the signaller then triggers the override which allows the signal to show a Call-On aspect . The TC override switch acts as an "Are you sure?" question for the signaller.
The button is represented by a red circle which turns into a full red roundel when pressed (by right click). The override auto-resets once the train passes the entrance signal or the route is pulled manually.
This picture is from the Brighton simulation showing the three TCO buttons at Hove, one for each platform.
The real buttons may be seen here .
See Track Circuit
Last edited by Edgemaster on 03/08/2018 at 16:00