had previously invented the first reliable safety valve and the scoop for picking up water from troughs between the tracks. He went on to improve the precision and interchangeability of tools and components. In 1862, locomotive work was transferred from Wolverton. Wolverton became the carriage works, while wagon building was concentrated at Earlestown. In 1853, Crewe had begun to make its own wrought iron and roll its own rails, and in 1864 installed a Bessemer converter for manufacturing steel. In 1868 it became the first place to use open-hearth furnaces on an industrial scale. It also built its own brickworks. Later the works was fitted with two electric arc furnaces. Production increased steadily and, with the sale to the Lancashire and Yorkshire Railway of ten 2-4-0 and eighty six 0-6-0 locomotives, privately owned manufacturers took out an injunction in 1876 to restrain the railway from producing anything but its own needs. This remained in force until British Rail Engineering Limited was established in 1969. By 1920 Crewe Works had grown into a poorly laid-out establishment with nine separate erecting shops, four of which could only handle smaller locomotives, and the LNWR sanctioned plans for a new large erecting shop which placed on hold until revised and implemented later by the LMS. London, Midland and Scottish Railway When the LNWR became part of the London, Midland and Scottish Railway (LMS) in 1923, its passenger locomotives were eclipsed by those of the former Midland Railway, which offered light, fast and frequent services. As traffic density increased, there was a need for longer trains and more powerful locomotives to haul them. In 1932, William Stanier became Chief Mechanical Engineer and set out to rationalise production. Since Crewe had experience with heavier locomotives and had its own steel making facilities, he chose it as his main production location. There followed the Princesses and Duchesses, along with the Jubilees and the "Black Fives". Crewe produced all the new boilers for the LMS, and all heavy drop stampings and forgings. It also produced most of the heavy steel components for the track and other structures. The 1935 documentary No. 6207; A Study in Steel about the construction of an LMS Princess Royal Class engine was filmed at the works. During World War II, Crewe produced over 150 Covenanter tanks for the army. British Railways After British Railways (BR) was formed in 1948, Robert Riddles introduced the