Under the Railways Act 1921 the majority of the railway companies in Great Britain (along with a few in Northern Ireland) were grouped into four main companies, often termed the Big Four. The grouping took effect from 1 January 1923.
The Big Four and their constituent companies, showing route mileage, were:
Over fifty railway companies were not covered by the grouping. Those in the following list were those organised on an independent basis, usually providing locomotives and rolling stock also. They are included under classification headings.
Joint lines in this respect were wholly owned by two or more other companies. If not all of the owning companies went into the same group then the joint company could not be grouped. Joint lines did not always operate any services: they owned the track, stations etc. and the services were operated by one or more of the parent companies:
The Railways Act 1921 only extended to Great Britain. Railways in Ireland and the Crown Dependencies were not affected unless owned by a railway company in Great Britain. The railways included in this section were standard gauge, unless otherwise noted:
The railways included in this section were standard gauge, unless otherwise noted:
The London, Midland and Scottish Railway (LMS) was a British railway company. It was formed on 1 January 1923 under the Railways Act 1921, which required the grouping of over 120 separate railways into four. The companies merged into the LMS included the London and North Western Railway, the Midland Railway, the Lancashire and Yorkshire Railway, several Scottish railway companies, and numerous other, smaller ventures.
The history of rail transport in Ireland began only a decade later than that of Great Britain. By its peak in 1920, Ireland had 3,500 route miles (5,630 km). The current status is less than half that amount, with a large unserviced area around the border area between Northern Ireland and The Republic of Ireland.
The South Yorkshire Joint Railway was a committee formed in 1903, between the Great Central Railway, the Great Northern Railway, the Lancashire and Yorkshire Railway, the Midland Railway and the North Eastern Railway to oversee the construction of a new railway in the Doncaster area of South Yorkshire, England. The five companies had equal rights over the line, each of the companies regularly working trains over it.
The Cambrian Railways owned 230 miles (370 km) of track over a large area of mid Wales. The system was an amalgamation of a number of railways that were incorporated in 1864, 1865 and 1904. The Cambrian connected with two larger railways with connections to the northwest of England via the London and North Western Railway, and the Great Western Railway for connections between London and Wales. The Cambrian Railways amalgamated with the Great Western Railway on 1 January 1922 as a result of the Railways Act 1921. The name is continued today in the route known as the Cambrian Line.
The Midland and Great Northern Joint Railway (M&GNJR) was a railway network in England, in the area connecting southern Lincolnshire, the Isle of Ely and north Norfolk. It developed from several local independent concerns and was incorporated in 1893. It was jointly owned by the Midland Railway and the Great Northern Railway, and those companies had long sponsored and operated the predecessor companies.
The London and North Eastern Railway (LNER) produced several classes of locomotive, mostly to the designs of Nigel Gresley, characterised by a three-cylinder layout with a parallel boiler and round-topped firebox. It produced the most famous locomotive of its day, 4468 'Mallard', the holder of the world steam locomotive speed record. It also built the world-famous 4472 'Flying Scotsman'. However, its locomotive inheritance was much greater than just the 'A4 Class', it also produced highly successful mixed-traffic and freight designs.
A joint railway is a railway operating under the control of more than one railway company: those companies very often supplying the traction over the railway.
The London and North Eastern Railway Class U1 was a solitary 2-8-0+0-8-2 Garratt locomotive designed for banking coal trains over the Worsborough Bank, a steeply graded line in South Yorkshire and part of the Woodhead Route. It was both the longest and the most powerful steam locomotive ever to run in Britain. It was built in 1925 with the motion at each end being based on an existing 2-8-0 design. The original number was 2395, and it was renumbered 9999 in March 1946, and then 69999 after nationalisation in 1948, although it retained its cab-side plate bearing its original number throughout its life. The locomotive ran for some time as an oil burner, and was tried out on the Lickey Incline in 1949–1950 and again, after the electrification of its home line, in 1955. These trials were unsuccessful, and so the locomotive was withdrawn in 1955 and scrapped.
The Great Central Main Line (GCML), also known as the London Extension of the Manchester, Sheffield and Lincolnshire Railway (MS&LR), is a former railway line in the United Kingdom. The line was opened in 1899 and built by the Great Central Railway running from Sheffield in the North of England, southwards through Nottingham and Leicester to Marylebone in London.
The history of rail transport in Great Britain 1830–1922 covers the period between the opening of the Liverpool and Manchester Railway (L&MR), and the Grouping, the amalgamation of almost all of Britain's many railway companies into the Big Four by the Railways Act 1921.
The "Big Four" was a name used to describe the four largest railway companies in the United Kingdom in the period 1923–1947. The name was coined by The Railway Magazine in its issue of February 1923: "The Big Four of the New Railway Era".
The Northern Counties Committee (NCC) Class S2 was a solitary two-cylinder compound 2-4-4T steam locomotive that was introduced for service on the 3 ft narrow gauge railways of County Antrim in north-east Ireland. It was heavily rebuilt from a BNCR Class S locomotive by the addition of a standard gauge boiler.
Ballycastle Railway was a 3 ft narrow gauge railway line which ran from Ballycastle to Ballymoney, both in County Antrim, Northern Ireland.
The Castlederg and Victoria Bridge Tramway was a 3 ft narrow gauge railway operating in County Tyrone, Northern Ireland. It opened in 1883 and closed in 1933.
The Lancashire, Derbyshire and East Coast Railway (LD&ECR) was built to connect coalfields in Derbyshire and Nottinghamshire with Warrington and a new port on the Lincolnshire coast. It was a huge undertaking, and the company was unable to raise the money to build its line. With the financial help of the Great Eastern Railway it managed to open between Chesterfield and Lincoln with a branch towards Sheffield from 1896. Despite efforts to promote tourist travel, the passenger business was never buoyant, but collieries were connected to the line, at first and in succeeding years. The Great Eastern Railway, and other main line companies, transported coal to the southern counties, and the company's engines took coal to Immingham in great quantities. The company had a fleet of tank engines.
The Nottingham Suburban Railway was a British railway company that constructed a line 3.65 miles (5.87 km) in length serving the north-eastern suburbs of Nottingham. It was built to shorten the distance by train to Ilkeston and towns on the Leen Valley railway line, and to connect important brickworks near Nottingham. The short line was expensive to build due to difficult topography; it opened in December 1889, and was worked by the Great Northern Railway; the trains used that company's Nottingham terminus.