A hardware or software system that links track switches and signals at junctions, crossings, or terminals. It ensures that a clear signal cannot be displayed for a train unless the route is properly aligned and locked, and no conflicting routes are cleared. This mechanical or electronic logic prevents collisions by making it physically impossible for a dispatcher to set up a catastrophic route.
The dispatcher is having trouble lining us through the interlocking at CP 45.
Related terms
Interlocking tower
A trackside building housing the levers and logic machines that control a local junction.
CBI
Computer-based interlocking is a digital signaling system that prevents conflicting train movements.
Centralized traffic control
A signal system that allows a single dispatcher to line switches and signals across hundreds of miles of track.
Switch points
The pair of movable, tapered rails in a turnout that steer wheels onto one route or the other.