Signals usually worked mechanically by wire from a signalbox 's lever frame to indicate the state of the line ahead. Having the signal arm placed horizontally (the Normal position) may indicate that the next section contains a train. A raised or lowered arm indicates the line is clear. The arm also has coloured filters (spectacles) blue/red for home signals and blue/yellow for distant signals which are moved in front of a lamp and when the signal is cleared they indicate to drivers the position of the signal at night.

A semaphore signal that lowers its arm to indicate the line ahead is clear.

A semaphore signal which raises its arms to indicate the line ahead is clear.

The signal which may control the entry into a section. It either shows the line is clear (the signal arm would be up) or another train is ahead (the signal arm would be horizontal).

A home signal within station limits where an outer home signal is positioned. The inner home signal is in advance of the outer home and usually to the rear of the signal box.

An additional signal placed before the home signal that protects trains shunting back past the home signal. It also indicates station limits at the approach end of a station.

A signal (its the red lever with the 4" white band around it) that may be positioned at the departure end of a platform to allow trains to run into the station and stop, even though there is a train in the next Section. the clearance of this signal is usually controlled by the acceptance of the train by the signalbox in advance (locked by the block).

A signal sited in Rear (approach side) of a home signal intended to give the driver advance warning of the aspect of the home signal and allow trains to move at faster speeds and increase braking distances. Distant signals came in two types - fixed and worked. Fixed distants were more commonly found on the approach to termini.

Any signal that has more than one route and is capable of displaying an indication of which route has been selected. A junction indicator will also be fitted to a junction signal to inform the driver which way a junction is set, by means of white lights.

A lineside signal which is permanently set at stop or caution. Most commonly found as a distant signal on the approach to a terminus and used to slow trains down on the approach to the end of the line.

A smaller than normal signal either ground disc or miniature signal arm that is used specifically to indicate whether or not particular shunting moves may take place. A shunting signal is usually represented on a modern image layouts with a colour light ground signal (Ground Position Light). the ground disc style normally face the opposite way to the normal direction of travel and are used for setting back moves (for example)