A safety critical element of a signalling system which prevents unsafe situations arising.
As a route is set, the Interlocking will verify that all points on the route are set and proved by 'detection' to be in the correct position.
The term also applies to signal lamp proving, insofar that the signal lamp is 'proved' to be working and showing the correct aspect before the preceding signal (in the rear) will display its appropriate aspect.
Where shunt signals exist between the entrance and exit signal (known in this situation as Preset Shunts ), each of these must be proved to be alight and showing a proceed aspect in order for the entrance signal to show a proceed aspect.
Last edited by GeoffM on 15/09/2016 at 03:00