Ventilation fan

© Transport for London
Collection of London Transport Museum
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Howden tunnel ventilation fan, built 1940

Trains, passengers, station machinery and lighting generate a lot of heat. To help ventilate tube tunnels and stations deep underground enormous fans are used. Manufactured by James Howden Co Ltd, this example was installed near Swiss Cottage station.

Engineering fact: These fans were also designed to be run backwards in the event of a gas attack during the Second World War. This had the effect of slightly pressurising the system, minimising the risk of gas seeping underground into the tunnels and station platforms.

Reference no: 1999/10684