Under the Whyte notation for the classification of steam locomotives, 2-4-0 represents the wheel arrangement of two leading wheels on one axle, four powered and coupled driving wheels on two axles, and no trailing wheels. The notation 2-4-0T indicates a tank locomotive of this wheel arrangement on which its water is carried in tanks mounted on the locomotive, rather than in an attached tender.
Other equivalent classifications are:
- UIC classification: 1'B (also known as German and Italian classifications)
- French classification: 120
- Turkish classification: 23
- Swiss classification: 2/3
- Russian classification: 1-2-0
The 2-4-0 configuration was developed in the United Kingdom (UK) in the late 1830s or early 1840s as an enlargement of the 2-2-0 and 2-2-2 types, with the additional pair of driving wheels giving better adhesion. The type was initially designed for freight haulage. One of the earliest examples was the broad-gauge GWR Leo Class, designed by Daniel Gooch and built during 1841 and 1842 by R and W Hawthorn and Company, Fenton, Murray and Jackson, and Rothwell and Company. Because of its popularity for a period with English railways, noted railway author C. Hamilton Ellis considered the 2-4-0 designation to have the nickname (under the Whyte notation) of 'Old English'.
During 1846-47 Alexander Allan of the newly established London and North Western Railway (LNWR) created the 'Crewe type' of locomotive, with a 2-2-2 wheel arrangement for passenger classes and 2-4-0 for freight. During the 1850s and 1860s these designs were widely copied by other railways, both in the UK and overseas.
During the mid-1840s Sir John Hawkshaw developed a new style of 2-4-0 passenger locomotive with outside cylinders in front of the leading wheels and the rear driving axle behind the firebox. This layout provided steady running at high speeds, despite a long overhang at the front. Joseph Beattie of the London and South Western Railway was one of the first British locomotive engineers to use this type on express locomotives. From 1858 he began experimenting with 2-4-0 designs for passenger work, culminating in his 'Seven-Foot' 2-4-0 express passenger locomotives built between 1859 and 1868. Beattie was also responsible for the long-lived 0298 Class of 2-4-0 well tanks designed for suburban passenger work in 1874, some examples of which were still working in 1961.
After 1854, the 'Hawkshaw type' of 2-4-0 was adopted by Beyer, Peacock and Company who built many examples of the type for export, including to the Swedish State Railways (Statens Järnvägar) in 1856 and the Zealand Railway in Denmark in 1870.
The Bavarian B V and Bavarian B VI 2-4-0 locomotives of the Royal Bavarian State Railways (Königlich Bayerische Staats-Eisenbahnen) were the first types to be produced in Bavaria in large numbers. 208 in all were built between 1853 and 1863. One example is preserved in the Nuremberg Transport Museum.
In New Zealand two classes of tank locomotive were built with the 2-4-0T wheel arrangement. They were the New Zealand Railways (NZR) D class in 1874 and the NZR L class in 1878, both classes having been designed for mixed traffic use.
Five D class locomotives were built by Dübs and Company in Glasgow, Scotland, nineteen were built by Neilson and Company and eleven were built by Scott Brothers Ltd. of Christchurch. The first members of the D class entered service in 1874 and all had been withdrawn from NZR service by the end of 1927, which allowed the D classification to be used again in 1929.
Of the thirty-three D class locomotives that were built, seven have been preserved although only D16 and D140 were in operational condition.
All ten L class locomotives were built by the Avonside Engine Company in Bristol. The first L class to be built entered service in 1878 and another nine L class locomotives were ordered. In 1893-94, three of the L class 2-4-0T locomotives were rebuilt to a 4-4-0 wheel arrangement at Newmarket workshops, with larger boilers and enlarged cylinders. This new design was classified La, but their limited coal bunker capacity remained a drawback. The solution was to add a trailing pony truck to accommodate a larger coal bunker, converting them to a 4-4-2T wheel arrangement. A further four L class locomotives were similarly converted. Three were not rebuilt, but sold to the Public Works Department between 1901 and 1903. Three new 4-4-2T locomotives were built in 1902-03. When the conversion program was completed in 1903, the classification for all ten the remaining NZR locomotives was changed back to L.
Of the ten L class locomotives that were built, numbers 207 (507), 208 (508) and 219 (509) have survived long enough to be preserved, all three operational.
A standard gauge railway line between Salt River and Wynberg in the Cape Colony, constructed with private capital, was opened to the public on 19 December 1864. The Cape Town Railway and Dock Company undertook to rent and operate the line and acquired three 2-4-0 tank locomotives as motive power for the line in 1865.
In 1872 the locomotives came onto the roster of the Cape Government Railways when it took over the operation of all railways in the Cape Colony. They remained in service on this line until after its conversion to dual standard-and-Cape gauges around 1872 and were retired in 1881, when sufficient Cape gauge locomotives were in service.
Between 1846 and 1880 the 2-4-0 was the standard type for passenger and mixed traffic locomotives and was built in large numbers by, amongst others, the LNWR (1846–96), the Midland Railway (1846–1880), the North Eastern Railway (1856–88), the Great Eastern Railway (1856–1902) and the Great Northern Railway (1849–97).
Most United Kingdom railways used 2-4-0s, including those designed by James Holden on the Great Eastern Railway, Matthew Kirtley on the Midland Railway, Joseph Armstrong on the Great Western Railway and Francis Webb on the London and North Western Railway. One of the latter's types, the Precedent (or Jumbo) class “Hardwicke” famously set outstanding records for the LNWR during the "Race to the North" in 1895.
United States of America
In the collection of the California State Railroad Museum is the J.W. Bowker locomotive, a 2-4-0 engine built by Baldwin Locomotive Works in 1875 for the Virginia & Truckee Railroad. Today the J.W. Bowker is the sole remaining Baldwin 2-4-0 in existence.
- Hamilton Ellis, Some Classic Locomotives, George Allen and Unwin, 1949, pp.19-32.
- Hamilton Ellis, Pictorial encyclopaedia of railways, Hamlyn, 1968, pp.53-4.
- D.L. Bradley, Locomotives of the London and South Western Railway, Part 1. Railway Correspondence and Travel Society, 1965, p.58.
- Bradley (1965), pp.52-76.
- Hamilton Ellis, Pictorial enclyclopaedia of railways, p.54.
- Holland, D.F. (1971). Steam Locomotives of the South African Railways, Volume 1: 1859-1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 15–17, 23. ISBN 978-0-7153-5382-0.
- Bertram Baxter, British Locomotive Catalogue 1825-1923, Vol.1. Moorland Publishing, 1977. ISBN 0-903485-50-8.