London Underground 1920 Tube Stock

The 1920 Tube Stock is notable for being the first tube stock with air operated doors. Forty cars (half control trailers, half trailers) was built for the Piccadilly Railway just after the First World War. They were marshalled into six-car sets along with twenty cars of Gate Stock which had been modified with air operated doors. The driving cabs had oval windows like contemporary F Stock.
1920 Tube Stock trailer, notice the central door post [3]


Information
Number built: 60 (40 new build, 20 conversions) (6-car sets)
Built: 1920-22
Builder: Cammell Laird
(conversions Gloucester Railway Carriage & Wagon Company)
Motor: 2 British Thomson-Houston electric motors per motor car
Power: 400 hp (298 kW) per motor car

Unlike standard practice in later trains, the air operated doors on the 1920 Tube Stock closed against a central post [1]. The doors were remotely controlled from a guard's panel at each end of the train [2], powered by compressed air [3]. To enable interoperability between the new and rebuilt stock, the new control trailers used the same BTH equipment as Gate Stock, and this was re-used from Gate Stock which had been converted to trailers.

The tube stock entered service in the early 1920s, they were considered to have drab interiors, especially compared to later stock, with mock leather seating. They had all longitudinal seating from new but gained some transverse seating during refurbishment as well as an improved interior. The 1920 Tube Stock was transferred to the Bakerloo Line in 1932 and withdrawn from passenger service in 1938. 

Although there were plans to re-use them on other lines most cars were scrapped after the Second World War. Five cars survived as an engineering instruction train until final withdrawal and scrapping in 1968.
Interior view [3]


[1] Brian Hardy, Underground Train File Tube Stock 1933-1959 (Capital Transport, 2001) p. 16
[2] Piers Connor, The London Underground Electric Train (Crowood Press, 2015) p. 83
[3] "New Piccadilly Railway Rolling Stock", The Electrical Review Vol. 87 No. 2, 247 (December 17 1920) p. 771