A mechanical or electrical device mounted beside or above the track that conveys operating instructions to the locomotive engineer. These devices display specific aspects using colored lights or movable arms to indicate track conditions, speed restrictions, or the requirement to stop. They ensure safe separation between trains and protect junctions.
Heard on the job
We caught a restricting railway signal at the interlocking and had to crawl the rest of the way into the yard.
Also heard as
- signal
- block signal
Related terms
Signal aspect
The visual appearance of a railway signal that conveys a specific rule to the crew.
Block signal
A fixed trackside light or semaphore that tells an engineer whether the track segment ahead is clear.
Home signal
An absolute signal that governs a train's entry into a specific interlocking or block.