In terms of running railways, signals are mechanical and electrical devices erected beside a railway to pass information relating to the state of the line ahead of the engine. Signalmen use these to direct an engine's crew to make certain movements or to stop from their signal boxes.
History
One winter, 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 by displaying the wrong aspic lunar for "Diverging" instead of red for "Danger".
On Sodor, most signals are lower-quadrant, meaning they point downward to indicate "go". Gordon and James once played a trick on Percy with non-existent "backing signals", so that when Percy came to an upper-quadrant signal which went up instead of down to indicate that he could go, he thought it was a "backing signal".
Gallery
The Railway Series
Main Series
Miscellaneous
External Link
- Railway signals and their descriptions from The Signal Box.