Track warrant control governs dark territory, where no signals show whether the track ahead is occupied, and many ABS lines without CTC, by having the dispatcher issue each train a track warrant with fixed limits. Only one train holds authority over a given stretch at a time unless the warrant says otherwise. Crews call the unsignaled stretches dark territory, and there a switch left lined wrong gives no signal warning at all.
Once we're past the end of CTC it's TWC all the way to the mine, so get a warrant before we leave the yard.
Also heard as
- track warrant control
- warrant territory
Related terms
Track warrant
A written authority from the dispatcher, copied by radio, that lets a train occupy a set stretch of main track.
CTC
Centralized traffic control: signals and switches controlled remotely by a dispatcher who routes every train.
DTC
Direct traffic control: authority granted by named blocks of track on unsignaled lines.
DS
Dispatcher, as said on the radio: the person who controls train movements over a territory.