Treadle (railway)
Videos
In railway signalling, a treadle is a mechanical or electrical device that detects that a train wheel has passed a particular location. They are used where a track circuit requires reinforcing with ad
An electro-mechanical treadle
A small treadle operates this flangeway greaser.
Railway signalling
Videos
Railway signalling, or railroad signaling, is a system used to control the movement of railway traffic. Trains move on fixed rails, making them uniquely susceptible to collision. This susceptibility i
A Class 66 locomotive (right) is waiting at a red signal while a First Great Western (now Great Western Railway) passenger train (left) crosses its path at a junction.
A block signal and a 130 km/h speed limit at kilometer post 547 in Iisalmi, Finland
Short signal blocks on the Toronto Transit Commission subway system. A train (not visible) has just passed the most distant, leftmost signal, and the two most distant signals are red (stop and stay aspect). The next closest signal is yellow (proceed with caution), and the nearest signal shows green (proceed).
Traditional mechanical signals on display at a railway station in Steinfurt, Germany