The London Underground 1972 Stock is a type of rolling stock used on the London Underground. The 1972 Stock was originally ordered to make up the shortfall in trains on the Northern line's 1959 Tube Stock fleet, but is currently used on the Bakerloo line. Following the withdrawal of the British Rail Class 483 EMUs in 2021, the 1972 Stock are now the oldest EMUs in passenger service in the United Kingdom. A total of 63 seven-car trains were built in two separate batches. Construction A total of 252 cars were built by Metro-Cammell at Washwood Heath. In the early 1970s, the 1938 Tube stock on the Bakerloo and Northern line was life-expired and due for replacement. Tentative designs for a new Northern line fleet were abandoned when the go-ahead was given for the Piccadilly line to be extended to Heathrow Airport. That required a totally new fleet of trains to replace the 1959 stock then in use. The plan was made to transfer the 1959 trains to the Northern, to allow the worst of the 1938 stock there to be scrapped, but there were only 76 1959 Tube stock trains, and the Northern line needed more than that to operate. Originally, it was planned to refurbish around 30 of the 1938 trains, but this was scrapped in favour of 30 new trains of the 1972 Mark 1 Tube stock. The 1972 Tube stock was ordered in a hurry, so there was no time to create a new design; the trains were based on the 1967 Tube stock on the Victoria line. Although almost identical looking, the 1972 trains had a guard and door controls in the rear car, and were not compatible with 1967 Tube stock. In later years some surplus 1972 Mark 1 cars were adapted to run with the 1967 trains on the Victoria line, being formed in the middle due to the lack of ATO equipment. A further 33 trains of 1972 Tube stock were ordered to provide service on the Northern line. The 1972 Mark 2 stock had slightly different interiors, such as dark blue seating moquette, unlike the red and grey on the earlier 1967 and 1972 cars. The biggest external difference was that the doors were painted red, with a London Transport roundel on the side of the carriages, rather than the Johnston lettering. Unlike the 1967 or 1972 Mark 1 trains, the