A collection of (one or more) levers housed on a frame. The levers may operate signals, sets of points or locking bars.

A panel for signallers with switches or buttons to cover the immediate local area. The panel is usually located in a facility close to the local area.

It may be possible to switch local panel operation over to CTC control.

A tabular sheet, designed by signal design engineers, that lists all the interlocking dependencies for an interlocking. Generally used to describe mechanical interlockings.

See also Control Table as applied to electrical and electronic interlockings.

A locomotive (sometimes called an engine) is defined as a wheeled vehicle consisting of a power unit that is used to draw or push trains along railway tracks. The power unit may be a steam engine, electric motors driven by a diesel powered generator (diesel-electric), a diesel engine driving the wheels through a hydraulic transmission (diesel-hydraulic) or electric motors supplied electricity from an outside source (overhead wire or trackside conductors).