Signals

In terms of running railways, signals are mechanical or electrical devices erected beside a railway to pass information relating to the state of the line ahead of the engine.

Signalmen use these to alert the engine's crew to stop when another engine passes in order to avoid an accident. However, sometimes engines do not pay attention.

One time, Henry was pulling "The Flying Kipper" when he collided with a goods train because snow and ice forced the signal down, making it appear that the line was clear.

On Sodor, all signals point upward to indicate that an engine needs to stop and downward to indicate "go". Gordon and James once played a trick on Percy about "backing signals". So when Percy came to a signal and it went up instead of down to indicate that he could go, he thought it was a "backing signal", James also knocked down two signals, once with some wellwagons of tractors, and another with Rocky's crane arm causing confusion and delay. However, in recent episodes, the signal for "go" has changed back to downwards.

Trivia

 * In the New Series, engines have been seen passing through red signals.
 * Since the CGI switchover, the signals have a different "clunk" sound.
 * The signals on Sodor are old-fashioned, semaphore railway signals, still used in some countries today, mostly in the United Kingdom.

Merchandise

 * ERTL (discontinued)
 * Wooden Railway
 * Motor Road and Rail (discontinued outside of Asia)
 * TrackMaster
 * Hornby (discontinued)