Track circuit interrupter

A track circuit interrupter may be fitted at catch points, [trap points] or buffer stops to maintain a track circuit in the 'occupied' state in the event of a derailment. The track circuit remains de-energised until the interrupter is replaced.
GK/RT0011 specifies the requirements for the provision of track circuit interrupters.
Image:Track [Circuit Interrupter - Diagram B.jpg|left|frame|Interrupter drawn as two filled triangles. Assume train has overrun 53 signal and 52A trap points and interrupter shows DBT T.C. on Down Line as blocked (twin red lights).]