The fundamental safety framework of railroad operations that prevents collisions by dividing a line into discrete sections. Under this method, a train cannot proceed past a signal or designated limit until the system confirms the track ahead is unoccupied. It relies on track circuits, signals, and dispatching rules to maintain a protective bubble of empty track around every moving consist.
The branch line still runs on a manual block system, so we need a track warrant before we can move.
Related terms
Block section
A defined length of track governed by signals that only one train may occupy at a time.
Block signal
A fixed trackside light or semaphore that tells an engineer whether the track segment ahead is clear.
Centralized traffic control
A signal system that allows a single dispatcher to line switches and signals across hundreds of miles of track.