thumb|left|An R Stock train composed of a mixture of unpainted aluminium and (white) painted steel cars The London, Midland and Scottish Railway (LMS) had taken over the L&NWR railway's service from Earl's Court and by the Second World War this had been cut back to an electric Earl's Court to Willesden Junction shuttle. Following bombing of the West London Line in 1940, the LMS and the Metropolitan line services over the West London Line were both suspended. This left the Olympia exhibition centre without a railway service, so after the war the Kensington Addison Road station was renamed Kensington (Olympia) and served by a District line shuttle from Earl's Court. R Stock, composed of new cars and the Q Stock trailers that had been built in 1938, replaced the trains with hand-operated sliding doors that remained. The new trains were built between 1949 and 1959, and after 1952 trains were constructed from aluminium, saving weight. One train was left unpainted as an experiment and considered a success, so between 1963 and 1968 trains were left unpainted or painted white or grey to match. The transfer of CO/CP Stock from the Metropolitan line in the early 1960s allowed some of the Q stock to be scrapped. The slow tracks on the former LT&SR line to Upminster were shared with steam locomotive hauled goods and passenger services, until 1961 when the District took over exclusive use of the DC electrified lines.
thumb|left|An R Stock train composed of a mixture of unpainted aluminium and (white) painted steel cars The London, Midland and Scottish Railway (LMS) had taken over the L&NWR railway's service from Earl's Court and by the Second World War this had been cut back to an electric Earl's Court to Willesden Junction shuttle. Following bombing of the West London Line in 1940, the LMS and the Metropolitan line services over the West London Line were both suspended. This left the Olympia exhibition centre without a railway service, so after the war the Kensington Addison Road station was renamed Kensington (Olympia) and served by a District line shuttle from Earl's Court. R Stock, composed of new cars and the Q Stock trailers that had been built in 1938, replaced the trains with hand-operated sliding doors that remained. The new trains were built between 1949 and 1959, and after 1952 trains were constructed from aluminium, saving weight. One train was left unpainted as an experiment and considered a success, so between 1963 and 1968 trains were left unpainted or painted white or grey to match. The transfer of CO/CP Stock from the Metropolitan line in the early 1960s allowed some of the Q stock to be scrapped. The slow tracks on the former LT&SR line to Upminster were shared with steam locomotive hauled goods and passenger services, until 1961 when the District took over exclusive use of the DC electrified lines.