1920 tube stock

The 1920 stock was constructed by Cammell Laird in Nottingham, England, these were the first stock to have air-operated doors, consisting of 40 carriages, 20 control trailers and 20 trailers, there were no driving motors constructed with these.

They were used with twenty converted 1906 or gate stock driving motors which had been converted to air-operated doors especially for their operation with the 1920 stock. These driving motors were replaced in 1930 with twenty examples of 'standard stock' driving motors.

The stock was introduced on the Piccadilly line, however they were unsuitable for operating on the open sections of the line and became considered drab in comparison to the new '[[1923 stock|Standard stock]]' trains, being installed onto the line. The motors were replaced and the carriages refurbished, the most notable of which was the abandonment of longitudinal seating for a central section of bay seating, beginning in 1927. The stock was then transferred to the Bakerloo line in 1930 for local workings.

A second refurbishment had been planned for use on the Northern and City line between Moorgate and Finsbury Park, however this was interrupted by the outbreak of the Second World War. The 1920 stock carriages where retired from service in 1938.

Between 1946 and 1948 the carriages where scrapped, with the exception of five carriages which where reconstructed into an instruction train, until they were scrapped in 1969.