Mechanical railway signalling installations rely on lever frames for their operation to interlock the signals, track locks and points to allow the safe operation of trains in the area the signals control. Usually located in the signal box, the levers are operated either by the signalman or the pointsman.
A mechanical lever frame inside the signal box at Knockcroghery in Ireland
Lever frame of the signal box Hausen im Tal, Germany: the signals are operated by the red levers, black levers with Arabic numerals are for points and blue levers with Roman numerals are for track locks. The box on the right of the lever frame is used for manual block signalling; the smaller green levers are used for operating the route locks. The interlocking apparatus is in the box behind the levers.
A three-lever ground frame at Kyle of Lochalsh, released by Annett's key
Truro Signal Box lever frame
A railroad switch (AE), turnout, or [set of] points (CE) is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off.
A right-hand railroad switch with point indicator pointing to right
Large stations may have hundreds of normal and double switches (Frankfurt am Main main station, Germany).
Abt switch used in the 1895-built Dresden Funicular Railway (photo of 1985)
Control stand of a defunct railroad switch on the way from Pyin Oo Lwin to Goteik viaduct (Myanmar)
