History of the London Underground and was followed by 1959 tube stock. After experiments with an AEC lightweight diesel multiple unit in 1952, steam trains were removed from the Central line following the electrification of the Epping–Ongar section in 1957. Between 1963 and 1970, London Transport reported directly to the Minister of Transport, before control passed to the Greater London Council. Electrification work on the Metropolitan line, suspended due to the war, had restarted in 1959. The line was electrified to and the unpainted aluminium (A Stock) replaced steam trains, British Rail providing services for the former Metropolitan line stations between Amersham and . The
London Underground infrastructure lines share all their stations and most of the track with other lines. The Bakerloo, Central, Jubilee, Northern, Piccadilly, Victoria and Waterloo & City lines are deep-level tubes, with smaller trains that run in two circular tunnels with a diameter of about , lined with cast-iron or precast concrete rings, which were bored using a tunnelling shield. It is these that were the "tube" lines, although since the 1950s the term "tube" has come to be used to refer to the whole London Underground system. Many of the central London deep-tube line stations, such as those on the Central and