During the First World War the government had taken control of the railways to co-ordinate the war effort. After the war ended it was decided that the railway companies could not competitively return to their prior state, and so the 120 existing railway companies were combined into four companies, which became known as the ‘Big Four’’. The London Midland and Scottish Railway, also known as the LMS, was founded on 1 January 1923. The London and North Western Railway (LNWR), Midland Railway (MR), Lancashire and Yorkshire Railway (LYR), North Staffordshire Railway (NSR), Highland Railway (HR), Furness Railway (FR), Glasgow and South Western Railway (G&SWR) and Caledonian Railway (CR) were merged. These eight large constituent companies were joined by 27 other smaller subsidiary railways. The LMS covered the Western half of the country, stretching from the London and the Midlands, through Yorkshire, Lancashire, and up to Scotland. In all the LMS had a total of 7,790 miles of track, which made it the largest railway of the Big Four. The London termini of the LMS were St. Pancras and Euston stations and it had works at Crewe, Horwich, Wolverton and Derby amongst other locations. In 1934 the LMS moved into a new headquarters at Euston House on Seymour Street (later renamed Eversholt Street) in London. Charles Napier Lawrence, 1st Baron Lawrence of Kingsgate was the first appointed chairman of LMS, he had previously been the chairman of the LNWR between 1921-1923. He was chairman of the LMS for one year, and was succeeded by Sir Guy Granet. The management structure was headed by a chairman and a deputy chairman, there was a board of directors that had initially had 20 members, made of men who previously worked for the constituent companies. The first General Manager was Arthur Watson from the LYR. There was a Deputy General Manager for Scotland, a post first held by D.A. Matthieson, formerly of the CR. J.H. Follows, from the Midland Railway, was the first Chief General Superintendent and S.H. Hunt, formerly of the LNWR, was the first Chief Goods Manager. The post of Chief Engineer was initially held by E.F.C. Trench, formerly employed by the LNWR. The first Chief Mechanical Engineer was G. Hughes from the LYR and his deputy was Sir Henry Fowler, from the Midland Railway. The management structure was re-organised from January 1926 and an Executive was set up, Sir Josiah Stamp was the first President of the Executive. From January 1927 four Vice-Presidents were appointed to replace the general managers on the Executive committee. The line was divided up for operational management into three geographical divisions, which were called Western, Midland and Northern. Each division was overseen by a General Superintendent who reported to the Chief General Superintendent. The main line of the LMS ran from London Euston to Wick over 729 miles. The LMS ran a number of joint railways with the London & North Eastern Railway and the Southern Railway. It ran the Cheshire Lines Committee, the Midland and Great Northern line between Peterborough, the Norwich and Lowestoft and the Manchester, South Junction and Altrincham suburban line with the London & North Eastern Railway. It also joined forces with the Southern Railway to run the Somerset and Dorset line between Bath, Burnham and Bournemouth. The LMS undertook a limited programme of electrification, mainly focusing on suburban lines in London and Manchester. The LMS owned many hotels, including the Queen’s Hotel in Leeds and the iconic Art Deco Midland Hotel at Morecombe Bay. The LMS also ran passenger steamers from Holyhead, Heysham and Stranraer over the Irish Sea to Northern Ireland and the Republic of Ireland. Following the 1947 Transport Act which nationalised the railways, the concerns of the LMS were taken over by the Railway Executive as part of the British Transport Committee. Within the Railway Executive, British Rail: London Midland Region assumed responsibility for the LMS’s former area of operations.

The Great Western Railway, also known as the GWR, was founded by Royal Assent on 31 August 1835. The idea of a railway from Bristol to London had first been mooted in 1824, and finally in 1833 a committee of four prominent Bristol businessmen, namely George Jones, John Harford, Thomas Richard Guppy and William Tothill, had joined together and provided impetus and capital for the project. It took two years to survey the line and push the necessary legislation through Parliament. The first train ran from Bristol to Bath on 31 August 1940, full services started in 1841 and in 1842 Swindon Locomotive Works started operation. The London terminus of the GWR was at Paddington station. At its inception, the GWR had a board of 24 directors which was divided into two committees based in London and Bristol. The first chairman, who sat on the London committee, was Benjamin Shaw and the first deputy chairman was Robert Bright, a member of the Bristol committee. Sir Daniel Gooch was the first Locomotive Superintendent, a post that came later to be known as the Chief Mechanical Engineer. The GWR did not have the post of General Manager until 1863, when Charles Grierson was appointed. The first Secretary was Charles Saunders. Charles Russell became chairman in 1839. The GWR’s first Engineer (a post that would later be called the Chief Civil Engineer) was the renowned Isambard Kingdom Brunel, and he held the post from March 1835 to September 1859. The GWR was overseen by a Board of Directors. At the turn of the century there were three departments under the General Manager. These were the General Department, New Works and Government Enquiries and Staff and Expenses. On the operational side of the GWR, the various different departments such as the Locomotive, Carriage and Superintendent, the Superintendent of the Line, the Goods Department and the Traffic Manager all used a similar administrative structure. These departments were headed by one manager and beneath this post responsibility was distributed into divisions based on geographical areas, which varied by department. The docks which were owned by the GWR were administrated separately from the railways under the control of the Chief Docks Manager. There were also facilitative administrative departments, as well as Hotels and Catering, Surveyor, Estate Agent, Stores departments and a Road Motor Engineer’s Department which operated the GWR’s road haulage service. Brunel insisted on using a broad gauge track, which caused problems both in the civil engineering projects to build the railway and also during operation. A Gauge Commission had been appointed in 1846 and brought about the Gauge Act of 16 August 1846 which noted the systemic advantages of narrow gauge but did not compel the GWR to convert the full length of their track. From 1846 a standard gauge third rail was added to board gauge lines. From around 1868, led by then Chairman Sir Daniel Gooch, the GWR began to convert the entire system to standard gauge, and this was completed on 23 May 1892. The main line of the Great Western Railway ran over the 118¼ miles between Bristol Temple Meads and Paddington station in London. The construction of the main line required several major engineering works. The chief among these was the two-mile long Box Tunnel between Bath and Chippenham. This challenging engineering work took around five years to complete, opening on 30 June 1841. Brunel also constructed viaducts and bridges, including the Maidenhead Bridge, opened on 1 July 1839 and the Royal Albert Bridge at Saltash which linked Devon and Cornwall across the River Tamar and which opened on 11 April 1859. The GWR had a road haulage operation, which connected with its rail freight services. The GWR also owned and operated a number of docks and harbours, and after the Grouping in 1923 the GWR became the world’s largest dock-owning company. It wholly owned 16 docks, including Plymouth, Swansea and Cardiff, and jointly owned five other docks. The South Wales ports mainly handled minerals and food, whilst passenger ships used Plymouth and Fishguard. The GWR’s docks and harbours allowed goods and passengers to transfer between rail and sea with ease. The GWR also owned its own hotels, which numbered eight by 1923. The showpiece hotel was the Great Western Royal Hotel which was connected to Paddington station. The Railways Act 1921 came into effect on 1 January 1923 and the multitude of smaller railway companies were consolidated in the Big Four. The GWR absorbed seven larger constituent companies as well as 26 smaller railways covering most of Wales, the Welsh Marches, Somerset, South Devon and Cornwall. It was third largest Big Four railway, with around 3,800 miles of track. The Great Western Railway, along with all the other Big Four railway companies was nationalised and taken over by the Railway Executive, part of the British Transport Commission from 1 January 1948. The Western Region of British Railways took over responsibilty for GWR's sphere of operations.

Sudan Railways is the main railway system in Sudan, operated by the government-owned Sudan Railways Corporation. It runs over 5000km of narrow gauge, single-track railroads that serve the northern and central parts of the country. The main line underwent construction in 1875, completed in 1899, and runs from Wadi Halfa to Khartoum, and southwest to Al Ubayyid via Sannar and Kosti. In 1904-5 a line between Swakin and Atbara was constructed with the two lines meeting at Saloom station, to facilitate export and import transportation. In 1906 the railway headquarters and workshops were moved from Wadi Halfa to Atbara, and since 1981 the company headquarters have been based in Khartoum. In the 1980’s Sudan Railways declined due to political instability and debt, with lines operating at only 20% capacity by 1989. In 2011-2012 a contract was signed to build a line from Nyala to Chad, extending to the capital of Chad, N’Djamena. In 2015 Sudan Railways had 60 trains available but which could only travel at 40km per hour due to poor track conditions, with President Omer Hassan al-Bashir promising modernisation of the Sudanese railways with Chinese funding.

Ceylon Government Railways (CGR) was developed in the 1850s to develop and unify Sri Lanka and was built by the British Colonial Government in 1864. The first train ran on 27 December 1864 and the main line between Colombo and Ambepussa officially opened on 2nd October 1865. The railway was initially built to transport tea and coffee to Colombo. Major population growth meant that passenger traffic increased and in the 1960s passenger traffic overtook freight as the main source of revenue. The railway network comprised of nine lines radiating from Colombo and connected many population centres and tourist destinations. Extensions were made to the main line in 1867, 1874, 1885, 1894 and 1924, extending its service to Kandy, Nawalapitiya, Nanu Oya, Bandarawela and Badulla, respectively. Many other railway lines were added to Ceylon Railway System within the first century of its life, such as a line to Matale in 1880, Coast Railway Line in 1895, Northern Line in 1905, Mannar Line in 1914, Kelani Valley in 1919, Puttalam Line in 1926, and Railway Line to Batticaloa and Trincomalee in 1928. Until 1953, Ceylon's railways operated steam locomotives. In the golden era, it enhanced its service by changing to diesel locomotives, under the leadership of Rampala. Various types of diesel locomotives were added to the service. Today the company is known as Sri Lanka Railways as Ceylon gained independence in 1948 and changed its name to Sri Lanka when it became a republic in 1972.