LONDON UNDERGROUND HISTORY

Our heritage: Signalling
A good signalling system is critical to the running of the railway. Signals regulate train traffic and ensure the safety of customers, yet the infrastructure associated with signalling is largely out of public view.

The earliest signals used on the railway were a ’semaphore’ system . much like the ones used by sailors. As electricity became more widely available on the network, semaphore signals were replaced by light-based signals. By showing a certain colour, or ’aspect’, the signal provides critical information about how and where to move a given train. These signals were controlled by levers monitored by a signaller responsible for a specific section of track.

The newest signalling on the Underground uses digital systems to transmit the location of a given train to a control room.

Find out more at www.ltmuseum.co.uk

[Images]:
Below left: This 1958 photo shows a signaller pulling levers in his cabin; each lever is connected to a signal on the line
Below right: Susan Atyeo was the first female signaller for London Underground; she qualified in 1979
Right: This 1953 photo removal of the semaphore-style at Hanger Lane junction


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A venture of the City of London, Transport For London, and the London’s Transport Museum. In this project, which is usually located in the subway stations, a sign is displayed on each platform with the history of the current train station, or a page in the history of the London Underground. The signs are next to the other signs with train line maps or advertisements.

The current sign is at Old Street Station, and it focuses on the train’s signaling system.

The station where the sign was located was photographed that day Click for a larger image

The number that appears on the sign frame is probably the serial number of the sign.