Acton Works is a London Underground maintenance facility in West London, England. It is accessed from the District line and Piccadilly line tracks to the east of Acton Town station, and was opened in 1922. It was responsible for the overhaul of rolling stock, and gradually took on this role for more lines, until the formation of the London Passenger Transport Board in 1933, when all major overhauls of underground vehicles were carried out at the works. By 1985, when rolling stock had become more reliable and maintenance intervals had increased, this function was devolved to depots on each line. Subsequently, Acton continued to overhaul major items after they had been removed from trains at the depots, and tendered for work, which included the conversion of the A60 Stock to One Person Operation. It is likely to be reorganised and expanded to house the departments displaced from Lillie Bridge Depot which is being demolished as part of the redevelopment of Earls Court Exhibition Centre.
The site housed the engineering design department for London Underground, and under the leadership of charismatic figures like William Sebastian Graff-Baker from 1922 until 1952 and Stan Driver in the 1960s, produced a series of elegant and innovative designs for batches of rolling stock. The department's nadir was the design of the 1983 Stock, which was produced without any input from an outside design agency. The stock was less than successful, and resulted in a decision that design agencies would always be involved in future rolling stock development.
Major rolling stock projects carried out at the works have included the refurbishment of 15 of the Metropolitan Railway electric locomotives in 1953, and the conversion of the experimental 1960 Stock for Automatic Train Operation trials on the Woodford to Hainault section of the Central line, in preparation for its use on the Victoria line. The works has also been the home of several works shunters. Two were made from redundant driving motor cars, cut in half and joined back to back. A third consisted of two cars of 1935 Stock, which had been converted at the works in 1969 for articulation trials, and acted as a shunter after the trials were completed. A fourth shunter was built by modifying two driving motor cars of 1938 Stock.