These compact signals are used in yards, terminals, and complex interlockings where tall signal masts would obstruct visibility or lack physical clearance. They govern slow-speed switching movements and indicate whether a specific route is lined and safe to enter.
Heard on the job
Keep it under ten, you've got a red ground signal at the end of the ladder track.
Also heard as
- dwarf signal
- pot signal
Related terms
Signal aspect
The visual appearance of a railway signal that conveys a specific rule to the crew.
Interlocking
An arrangement of signals and switches interconnected to prevent conflicting train movements.
Restricted speed
A speed slow enough to stop within half the distance you can see, used whenever the track ahead may be occupied.