In 1910 the state-owned South African Railways and Harbours (SAR&H) organisation was created, after the four colonies of the Cape, Natal, Transvaal and the Orange Free State were amalgamated into the new Union of South Africa. In 1916, SAR&H took over the activities of the Central South African Railways, the Cape Government Railways and the Natal Government Railways. In 1924 the last privately owned railway line in South Africa was taken over by SAR&H; the New Cape Central Railway between Worcester and Voor Bay. In 1920 electrification of South Africa’s railways was completed, and in 1924 the first electric test train ran between Ladysmith and Chieveley in Natal. In 1950 the first portion of the new Johannesburg station was opened and construction was completed on the huge workshops complex at Koedoespoort. In 1960, diesel locomotives were introduced on a large scale to SAR&H. In 1981, SAR&H changed its name to South African Transport Services (SATS) and took on South Africa’s railway, harbour, road transport, and aviation and pipeline operations.

In 1900 the British Westinghouse Electrical & Manufacturing Co Ltd bought land in Trafford Park and built a factory which went into production in 1902 for the manufacture of mechanical and electrical equipment for the generation, transmission and use of electricity. In 1919, Trafford Park Works became owned by British Westinghouse’s successor, Metropolitan-Vickers Electrical Company (MV). The main shops, in common with factory construction throughout Trafford Park, were single floor type, with bays 1,000 feet in length, and had direct railway communication with the docks and trunk systems of the country. The main office block was a copy of the Westinghouse building in Pittsburgh, USA and the factory was to the American design and used imported steelwork for construction. Products manufactured at the Works included gas engines, stationary steam engines, electric generators, transformers, switchgear, meters, motors, control gear, and arc lamps. During the First World War, British Westinghouse built some small petrol-electric locomotives for the War Department Light Railways. In 1928 the Works were taken over by Associated Electrical Industries (AEI), which merged Metropolitan-Vickers and British Thomson-Houston, though these two companies continued their own trading names. Traction design and manufacture was always a minority of the workload at Trafford Park with the largest operations generally turbine manufacture. Very few vehicles were built there, and traction machines (i.e. motors, inductors and generators) were largely built in other places – notably at Sheffield or Rugby. Trafford Park traction manufacture was largely that of assembling control gear – contactors, switches, drivers’ controllers, camshaft controllers, relays etc. and building these into frames or equipment boxes for installation in vehicles made elsewhere. An important part of the Trafford Park Works site was the general switchgear operation, mainly for generation or distribution installations. The on-site Switchgear Testing Company was a “testing house” for these products and contributed to testing and development of traction circuit breakers and switchgear. During the Second World War MV acting for the Ministry of Aircraft Production produced more than a thousand Lancaster Bombers in the adjacent Mosley Road building. The company also manufactured war munitions and in the laboratories developed what became known as Radar. In 1959 the newly formed AEI Traction Division established its headquarters at Trafford Park, with a product range that included electric and diesel-electric locomotives; electrical equipment for tram-cars, trolley buses and trolley mining locomotives and traction motors. AEI was taken over by the General Electric Company (GEC) in 1967 whose Witton Works closed in 1969, with the design office and traction manufacture transferred to Trafford Park, as a result of the GEC reorganisation and mergers. GEC Traction Ltd took over the Works in 1972. In 1990 the former Low Voltage Switchgear site at Trafford Park (West Works) was renovated to be the new manufacturing facility for GEC Alsthom Traction, with an electronics workshop, machine shop and plating baths, and an assembly shop for switchgear, equipment cases and power modules. This building was vacated in 1998 when power modules and switchgear was moved to Tarbes in south west France. The Works housed the administrative, commercial and accounting functions, the majority of the design departments and the development section with its associated workshops and laboratories. The manufacturing area was devoted primarily to the production of components of traction control and railway signalling equipment. In 1993, as part of the rationalisation of the equipment group, it was announced that the headquarters of GEC Alsthom Traction would move to Preston, leaving only Power Module design and manufacture at Manchester, with the eventual closing of all activities at Trafford Park in 1998. The iconic original Westinghouse building was demolished and the site is now (2015) largely devoted to container handling and logistics operations.

Metropolitan-Vickers Electrical Company Ltd (Metrovicks) built an armament factory on Attercliffe Common in Sheffield, a 9-acre site for the manufacture of traction motors in 1921. In 1923 it was made into a self-contained traction motor factory with its own engineering department and the manufacture of complete locomotives and electric delivery vehicles. Metrovicks merged with British Thomson-Houston Co Ltd (BTH) in 1928 to form the holding company Associated Electrical Industries (AEI) still trading under each individual company’s name. In 1931, Metrovicks bought the whole Attercliffe Common Works apart from the stamp shop which made 4 1/2 acres of single-storey building available for traction work. During the Second World War the Works suffered bomb damage and became the major supplier of dc generator/ high frequency alternator sets for aircraft and a ‘shadow’ factory was set up at Bamford. Together, 140000 sets were produced with military work continued at the factory up to the 1970’s. In 1956 Attercliffe Works became the feeder department for the new AEI factory on Greenland Road also located in Sheffield for the manufacture of smaller type of machines, traction gears. AEI created a subsidiary called AEI Traction Ltd in 1959, which took over the Attercliffe Common works to manufacture traction motors, generators, gears and other machines such as motor-generator sets used for converting the high traction voltage to a safer voltage suitable for train lighting, heating, battery-charging and for the control equipment on locomotives and suburban electric trains. The General Electric Company Ltd (GEC) took over AEI in 1967 and Attercliffe Works became owned by a subsidiary of GEC, GEC Traction Ltd who designed and manufactured a full range of traction machines and control equipment for electric vehicles. All British Railways a/c electric loco motors and motor coach d/c motor orders for Hong Kong and Korea up to the mid-seventies were built at the Works. The Attercliffe Common works closed in 1985 when GEC and the French Alsthom group merged in 1989, and the design and manufacture of motors and inductors moved to GEC Preston works and gears moved to GEC Rugby works.