The R-stock was commissioned between 1949 and 1959 and ran on the District line until 1983. It comprised 246 newly constructed cars and 132 cars converted from 1938 Q-stock. Notable features include it being the first stock on the Underground with fluorescent lighting and the fact that every car was equipped with traction motors. Car number 22679 was one of many constructed in aluminium alloy, which reduced the weight by 5.4 tons. It formed part of an experimental eight-car train left unpainted to save costs.