The English Electric Company was formed on 14th December 1918 and over the following year acquired Dick, Kerr & Company of Preston, Willans & Robinson of Rugby, the Phoenix Dynamo Manufacturing Company of Bradford, and Coventry Ordnance Works. After the First World War the various German owned Siemens works were distributed to different UK companies and in November 1919 English Electric acquired the Siemens Brothers Dynamo Works at Stafford, which became the company headquarters in 1931. Coventry Ordnance, primary output naval guns, did not feature in the gradual product rationalisation which took place between the First World and Second world Wars. Willans & Robinson’s Rugby works specialised in prime movers, steam, hydro and internal combustion, and their Stafford works on power station and distribution electrics, including transformers and large electric machines for applications such as mining and steel works. Dick Kerr & Company continued building equipment and vehicles for bus, tram and railway applications with the Phoenix Dynamo Manufacturing Company concentrating on medium and small electrical machines. Involvement with aircraft continued a small scale. By 1929 the company was in financial trouble and an American syndicate fronted by Lazard Bros. put in new capital. In 1930 Westinghouse of Pittsburgh entered into an agreement with the company for the exchange of technical information relating to steam turbines and electrical apparatus. This cooperation continued into the 1950s. 1930 saw the closure of Preston West works and the transfer of traction electrical design and manufacture to the Phoenix Dynamo Manufacturing works. The Westinghouse influence included top management changes with Sir H Mensforth becoming chairman and George Nelson managing director. Both had been with British Westinghouse at Trafford Park. The early 1930s saw a remarkable improvement in the company’s finances and domestic appliance manufacture was started at Bradford and Stafford. In 1936 they began production of diesel locomotives at Preston and were later involved in the production of the Deltic locomotive for British Rail, presaging the end of steam traction in the UK. Extensive shadow factory building for war production commenced in the late 1930’s, including at Preston East works and Salmesbury for aircraft production and at East Lancashire Road, Liverpool for D. Napier aero engines. A large variety of military equipment built during the war included thousands of Cromwell tanks from Stafford and over 3000 Handley Page Hampden and Halifax bombers from Preston and Salmesbury. After the war manufacture of smaller products from Bradford and Stafford moved to the large Liverpool works. This included electrical distribution transformers, switchgear, fuse gear, fractional horsepower motors and domestic appliances. Napier’s continued engine manufacture with the development of the ’Deltic’ diesel engine, mainly for marine applications. The nearby Netherton works took over the manufacture of large hydro-electric turbines and generators from Willans and Stafford. In 1942 English Electric acquired D. Napier & Son Ltd and Marconi in 1946. The company went on to extend their railway interests with the acquisition of the Vulcan Foundry and Robert Stephenson and Hawthorn Ltd in 1955. The company tried to take over The General Electric Company (GEC) in 1960 but failed. Traction manufacture, but not the offices, moved back to Preston East works and ‘K’, ‘RK’ and ‘V’ engine design and manufacture moved from Willans to Preston West works which was now also used for locomotive building. Kidsgrove works in Stafford made industrial controls and for a while was a major player in the UK computer industry, merging with Leo Computers and then into ICL. Train performance calculations were an early user of the mid-fifties ‘Deuce’ computer. Preston also became a major player in the aircraft industry taking over the wartime RAF/USAF base at Warton aerodrome - major design and manufacture contracts included Canberra bombers and Lightning fighters. Rationalisation in the 1960s resulted in English Electric Aviation becoming 40% of the new British Aircraft Corporation. In 1961 English Electric took over Dorman Diesels Ltd which in turn had acquired W. G. Bagnall Ltd. In 1966 English Electric Diesels merged with Ruston and Hornsby which already included Paxmans. This company eventually became GEC Diesels. Elliott Automation was acquired in 1967. The following year GEC took over English Electric, ending its independent existence.

In 1959 Associated Electrical Industries (AEI) created a self-contained company named AEI Traction Division to control the railway activities of both Metropolitan Vickers Electrical Company Ltd and British Thomson-Houston (BTH). Included in this company were the interests of the Metropolitan-Vickers General Railway Signal Co., (later to become GEC General Railway Signal). The newly formed company established its headquarters, at Trafford Park, Manchester, and operated from three other sites, Attercliffe Common in Sheffield, Rugby Works, and Stockton Works supplying traction motors, machines, control gear and mechanical parts of locomotives. AEI Traction Limited’s product range encompassed electric and diesel-electric locomotives; electrical equipment for tramcars, trolley buses, trolley mining locomotives, traction motors and gears. In 1969 AEI Traction Division merged with English Electric Traction to form English Electric-AEI Traction Division.

The British Thomson-Houston Co. Ltd., (BTH) was created as a subsidiary of the General Electric Company, USA in 1896 to exploit the sale of products in the United Kingdom. BTH was a reconstruction of an existing firm, Laing, Wharton and Down (1886). The BTH manufacturing works were based at Rugby, Warwickshire and the company’s products included induction motors, alternators, switchgear, turbo-generators and turbines, as well as a large number of rotary converters and motor converters, primarily for chemical plants. During the First World War, BTH’s most significant contribution was the development of marine apparatus for the naval service. The 1920s saw a period of vast expansion for the company with new extensions built at many of its factories such as Willesden, Birmingham, Chesterfield and Lutterworth. BTH amalgamated with Metropolitan-Vickers Electrical Company Ltd to form Associated Electrical Industries (AEI) in 1928 although both companies retained their separate identities and continued to compete for the same contracts. BTH developed manufactured electric torpedoes and electrical components for aircraft engines, munitions, etc., during the Second World War and in 1935 independently of each other, BTH and Metropolitan-Vickers were the first two companies in the world to construct jet engines.

The Great Indian Peninsular Railway (GIPR) came into existence on April 16, 1853, with the line running from Bombay to Kalyan. The aim was to open a channel to transport trade from cotton growing districts to beyond the Ghats. The GIP Railway was purchased by the Government of India on 1st July 1900 and amalgamated GIP with the Indian Midland Railway. In 1951 the GIPR combined with the Nizam Guaranteed State Railway, Dholpur State Railway and the Scindia State Railway to form a zone of Indian Railways named Central Railway.

In 1937 Robert Stephenson & Co. Ltd purchased the locomotive department of R & W Hawthorn Leslie & Co. Ltd. They became Robert Stephenson and Hawthorns Ltd. The policy was to concentrate the building of main line locomotives at Robert Stephenson’s Darlington works and industrial locomotives at Forth Banks. In 1944 Vulcan Foundry acquired Robert Stephenson and Hawthorns Ltd, ending Hawthorns' 137 year connection with Forth Banks. In 1955 Vulcan Foundry became full members of the English Electric group of companies, which became part of the GEC group of companies in 1968.

The Great Southern Railway of India (SIR) was renamed South Indian Railway on the 1st Jan 1891. SIR together with the Guntakal-Villupuram State Railway formed to become a new company called “South Indian Railway Company Limited”. In April 1951 the railway was integrated into a single zone with Madras and Southern, Marhatta Railway and Mysore Railway to form the Southern Railway zone of Indian Railways.

The Japanese Government Railway (JGR) was operated by the imperial government from 1872. In 1949, JGR was reorganised to become a state-owned public corporation named the Japanese National Railways.

Metropolitan-Vickers Electrical Co Ltd was the new trading name given to British Westinghouse Electric and Manufacturing Co on 8 September 1919. The predecessor company had sold its controlling share to the Metropolitan Carriage Wagon Co in 1916 in order to gain membership of the Federation of British Industries. In 1919, Vickers acquired the Metropolitan Carriage Wagon Co, along with its controlling share in British Westinghouse, prompting the change in name to Metropolitan-Vickers Electrical Co Ltd. The American owned British Westinghouse had established its English operations at Trafford Park in 1899, and Metropolitan-Vickers Electrical Co Ltd continued on the same site from 8 September 1919. The company was initially known for its electricity generators, later diversifying into the manufacture of steam turbines, switchgear, transformers, electronics and railway traction equipment. The passing of the Electricity (Supply) Act in 1926 provided a boost to the company’s post-war fortunes, with the creation of the National Grid generating demand for the company's products. In 1928, Metropolitan-Vickers Electrical Co Ltd merged with its rival British Thomson Houston Co Ltd, retaining both names for trading purposes. The following year, on 4 January 1929, Associated Electrical Industries Ltd (AEI) acquired Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd. Again, both trading names were retained, and a fierce rivalry was established between the firms which the parent company was unable to control. In 1931, Sir Felix Pole joined Metropolitan-Vickers Electrical Co Ltd as its new chairman. He oversaw a period of expansion for the company leading into the Second World War. In 1939, seeking a more concise name for the company, the Board of Directors decided upon Metrovicks, which became interchangeable with the official company name of Metropolitan-Vickers Electrical Co Ltd. Under Sir Felix Pole's chairmanship, Metropolitan-Vickers developed new products for the aviation industry and during the war was one of the sites where Lancaster bombers were built. In 1941, the company developed the first British axial-flow jet engine, the Metrovick F.2. Following the Second World War, the company appointed Oliver Lyttelton as chairman, with the aim of increasing the efficiency and productivity of AEI. Despite his success in achieving this aim, Lyttelton was unable to resolve the commercial rivalry between Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd. During his second period as chairman, from 1954-1963, Lyttelton, now Lord Chandos, oversaw the development by Metropolitan-Vickers Electrical Co Ltd of the first commercial transistor computer, the Metrovick 950. Chandos also resolved to extinguish the competition and internal divisions between Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd, and both company names ceased to be used from 1 January 1960, with all subsidiaries going on to trade under the name of Associated Electrical Industries Ltd.

In 1929 Vickers Ltd and Cammell Laird merged their rolling stock activities in a new company, the Metropolitan-Cammell Carriage, Wagon and Finance Company Ltd with Vickers and Cammell Laird each holding 50% of the shares of the new company. Following the Second World War, the company manufactured carriages for the railways of the world, including UK, USA, Canada, South Africa, Hong Kong, Singapore, Brazil, Jamaica, and Egypt. In addition, the company manufactured mineral wagons, diesel multiple units and locomotives. However, over this period of sustained high output, international industrial development together with reductions in home market demand as orders were fulfilled, led to the necessity to reduce capacity and in 1962 the Saltley Works were closed and eventually the whole enterprise was concentrated at the Midland Works offices at Leigh Road, Washwood Heath. In the 1970s Metro-Cammell specialised in the design and construction of rapid transit vehicles for customers such as London Underground, Tyne and Wear Metro, Hong Kong Mass Transit Corporation and the Kowloon Canton Railway Corporation. They also built Maglev vehicles for Birmingham Airport, diesel multiple units for BR and Mk IV coaches for BR. In May 1989 the Laird Group sold their transportation interests to GEC Alsthom and Metro-Cammell became part of the new Anglo-French Power Generation and Transportation Group. This led to involvement in the construction of the Eurostar trains for the Channel Tunnel project. The name Metro Cammell disappeared forever in 1998 when the owners floated the company under the name Alstom.