Under the Whyte notation for the classification of steam locomotives, 0-4-0 represents one of the simplest possible types, that with two axles and four coupled wheels, all of which are driven. In normal circumstances, the wheels on each end of the axles are connected with coupling rods to form a single driven set.
In Britain the Whyte notation of wheel arrangement was also often used for the classification of electric and diesel-electric locomotives with side-rod coupled driving wheels.
Other equivalent classifications are:
- UIC classification: B (also known as German classification and Italian classification)
- French classification: 020
- Turkish classification: 22
- Swiss classification: 2/2
In the UIC classification used in Europe and, in more recent years, in simplified form in the United States, an 0-4-0 is classified as B (German and Italian) if the axles are connected by side rods or gearing and 020 (French), independent of axle motoring. The UIC's Bo classification indicates that the axles are independently motored, which would be 0-2-2-0 in the Whyte notation.
0-4-0 locomotives were built as tank locomotives as well as tender locomotives. The former was more common in Europe and the latter in the United States, except in the tightest of situations such as that of a shop switcher where overall length was a concern.
The terms four-wheeled and four-coupled are often used for 0-4-0 locomotives, but these terms can also encompass other wheel arrangements. For example, Stephenson's Rocket was an 0-2-2 four-wheeled locomotive.
A four-wheeled configuration, where all the wheels are driving wheels, uses all the locomotive's mass for traction but is inherently unstable at speed. The type was therefore mainly used for switchers (USA) and shunters (UK). Because of the lack of stability, tender engines of this type were only built for a few decades in the UK. They were built for a longer period in the USA.
The possible tractive effort of an 0-4-0 within normal axle load limits was not enough to move large loads. By 1900 they had therefore largely been superseded for most purposes by locomotives with more complex wheel arrangements. They nevertheless continued to be used in situations where tighter radius curves existed or the shorter length was an advantage. Thus they were commonly employed in dockyard work, industrial tramways, or as shop switchers.
0-4-0T tank engines were introduced in the early 1850s. The type was found to be so useful in many locations that they continued to be built for more than a century and existed until the end of the steam era.
Finland had the E1 and Vk4 classes with an 0-4-0 wheel arrangement.
The E1 was a class of only two locomotives, numbered 76 and 77.
The Vk4 was also a class of only two locomotives, built by Borsig Lokomotiv Werke (AEG) of Germany in 1910. The Vk4s were used at a fortress, and were eventually also used in dismantling the fortress, after which one locomotive went into industrial use and was scrapped in 1951. The other was sold to the Finnish Railways and nicknamed "Leena". It became no. 68 and is now the oldest working broad gauge locomotive in Finland, being preserved at the Finnish Railway Museum.
The Semarang-Cheribon Stoomtram Maatschappij (SCS) imported 27 standard gauge 0-4-0T locomotives of the B52 class between 1908 and 1911, originally to operate services from Kalibrodi-Semarang to Tanggung and Yogyakarta. They were built by Sächsische Maschinenfabrik in Chemnitz, Germany. They were a modern locomotive design for the time, equipped with a superheater.
All 27 locomotives were in existence at the end of 1960, but by 1970 only 15 units remained. Two locomotives have been preserved, B5212 at the Taman Mini Indonesia Indah Museum of Transport and B5210 at the Railway Museum Ambarawa.
South Africa 
Seven feet gauge 
In 1874, during excavation work to improve the facilities at Table Bay Harbour, a 7 ft (2,134 mm) gauge 0-4-0T locomotive was acquired from Fletcher, Jennings to haul tip-wagons. A second locomotive was added in 1879, built by Black, Hawthorn, followed by a third in 1894, built by Hawthorns and Company (Hawthorns of Leith) on sub-contract from Black, Hawthorn.
Standard gauge 
The first railway locomotive to run in revenue earning service in South Africa was a small 4 ft 8 1⁄2 in (1,435 mm) standard gauge 0-4-0WT well tank engine named "Natal", manufactured by Carrett, Marshall and Company of Leeds. It made its inaugural run from Market Square to Point station in Durban during the official opening of the first operating railway in South Africa on Tuesday, 26 June 1860.
Cape gauge 
During the late 19th and early 20th centuries, a number of 0-4-0 tank and saddle tank locomotives were imported into South Africa, most of them for use in harbours. Many of these locomotives came into South African Railways (SAR) stock in 1912, but were never classified.
- Three 0-4-0ST locomotives were acquired for the Port Elizabeth Harbour Board in 1873 and 1874, built by Manning Wardle & Company. They were the first 3 ft 6 in (1,067 mm) Cape gauge locomotives to see service in South Africa.
- Between 1874 and 1882 nine saddle-tank locomotives were acquired for the Port Elizabeth, East London and Table Bay Harbour Boards, built by Hunslet Engine Company. Four of them survived to come into SAR stock.
- In 1881 two 0-4-0ST locomotives were acquired from Ruston, Proctor. One went to the Kimberley diamond mines and the other to the Cape Government Railways (CGR) for use during the construction of a temporary rail bridge across the Orange River at Norvalspont. In the process the CGR locomotive, nicknamed "Coffee Pot", became the first locomotive to cross the border between the Cape Colony and the Orange Free State.
- Fifteen saddle-tank locomotives were acquired from Black, Hawthorn and Company and Chapman and Furneaux between 1889 and 1898, for use by the Table Bay and Port Elizabeth Harbour Boards. Twelve of these survived to come into SAR stock, but were not included in the renumbering schedules.
- In 1892 five saddle tank locomotives were imported, built by Neilson and Company for the Natal Government Railways (NGR). One was later sold to the Pretoria-Pietersburg Railway (PPR), where it was named "Natal". In 1912 four of these locomotives, including the ex PPR locomotive, were taken onto the SAR roster as unclassified locomotives, described as "Durban Harbour engines" and "Pretoria Works Shunting engines". They were not included in the SAR renumbering schedules.
- Between 1894 and 1901 eight 0-4-0ST locomotives were delivered to the Port Elizabeth Harbour Board, four built by Black, Hawthorn in 1894 and 1895, two by Chapman and Furneaux in 1901 and two by Hudswell, Clarke, also in 1901. All of them came into SAR stock, but were not included in the renumbering schedules.
- In 1902 an 0-4-0ST locomotive, named "Congella", was delivered to the Natal Harbour board from Hudswell, Clarke.
- In 1903 a single 0-4-0ST locomotive, built by New Lowca Engineering, was delivered to the Port Elizabeth Harbour Board.
Some locomotives also entered Harbour Board service as previously owned. Two locomotives named "Stormberg" and "Thebus" were originally built by Hudswell Clarke for the South African Public Works Department in 1903. They were acquired by the SAR in 1916, but were named instead of being classified and numbered.
In 1941, long after the Harbour Boards had ceased to exist, a contractor’s locomotive that had been used on the Foreshore land reclamation project in Cape Town, built in 1913 by Orenstein & Koppel and numbered SAR-H&NW 69, was bought by the SAR for use in Table Bay Harbour.
Narrow gauges 
In 1886 and 1887 three 0-4-0WT condensing steam locomotives were built for the 2 ft 6 in (762 mm) narrow gauge line of the Cape Copper Company in Namaqualand by Kitson and Company of Leeds. They were later rebuilt as conventional 0-4-0 tank locomotives.
In 1900 the British War Office placed two Sirdar class 0-4-0T tank steam locomotives in service on a 2 ft (610 mm) narrow gauge line near Germiston in the Zuid-Afrikaansche Republiek, where the Royal Engineers had established a siege park during the Anglo-Boer War. The locomotives were built by Kerr, Stuart and Company.
At the end of the war the two Sirdar locomotives were sold to a farmer, who used them on a firewood line between Pienaarsrivier and Pankop, until the line and locomotives were taken over by the Central South African Railways (CSAR). In 1912, when these locomotives were assimilated into the SAR, they were renumbered with an "NG" prefix to their numbers. When a system of grouping narrow gauge locomotives into classes was eventually introduced by the SAR somewhere between 1928 and 1930, they were classified as Class NG1.
United Kingdom 
Tank locomotives 
The tank engine version of the wheel arrangement began to appear in the UK in the early 1850s, with the first significant class being six saddle tanks designed by Robert Sinclair (locomotive engineer) for the Caledonian Railway.
By 1860 the type was very popular and it continued to be built in significant numbers for both mainline and industrial railways, almost to the end of steam traction. Hudswell Clarke were supplying industrial saddle tanks until at least 1947, and both Barclay and Robert Stephenson and Hawthorns until 1949.
An interesting variation on this theme were the traction engine based railway locomotives built by Aveling and Porter.
Tender locomotives 
The first 0-4-0 to use coupling rods was Locomotion No. 1 built by Robert Stephenson and Company for the Stockton and Darlington Railway in 1825. Stephenson also built the Lancashire Witch in 1828, and Timothy Hackworth built Sans Pareil which ran at the Rainhill Trials in 1829. The latter two locomotives later worked on the Bolton and Leigh Railway.
During the 1840s the wheel arrangement was widely used by Edward Bury on the bar-framed locomotives built for the London and Birmingham Railway. However, with the exception of a few isolated examples used by the smaller companies such as the Cambrian Railways, the Furness Railway and the Taff Vale Railway, and four examples built by Edward Fletcher (engineer) of the North Eastern Railway between 1854 and 1868, the 0-4-0 tender locomotive had been largely superseded on Britain's main-line railways by 1850.
United States of America 
Tank locomotives 
An early example of the 0-4-0T type was the Baltimore and Ohio Railroad's Atlantic no. 2, built in 1832 by Phineas Davis and Israel Gartner. In the USA the 0-4-0T tank locomotive was principally used for industrial railway purposes.
Tender locomotives 
In the USA, the Best Friend of Charleston was the first locomotive to be built entirely within the United States. It was built in 1830 for the South Carolina Canal and Rail Road Company by the West Point Foundry of New York.
The Pennsylvania Railroad kept producing 0-4-0 classes long after all other major railroads had abandoned development of the type, building their final A5s class into the 1920s. The A5s was a monster among 0-4-0s, larger than many 0-6-0 designs, with modern features found on few others of its type, such as superheating, power reverse, piston valves, and several others. The Pennsy continued to build the type because it had a large amount of confined and tight industrial track, more than most other railroads had.
0-4-0 Diesel locomotives 
The wheel arrangement was also used on a number of small 0-4-0DM diesel-mechanical shunters produced by John Fowler & Co. and other builders in the 1930s and earlier. Similarly, it was perpetuated on a number of diesel-mechanical and 0-4-0DH diesel-hydraulic classes between 1953 and 1960 (see the List of British Rail modern traction locomotive classes). Many of these were later sold for industrial use.
- Whyte notation
- Shepherd, Cliff, ed. (December 2006). "Four-coupled or four-wheeled, A cautionary note". Industrial Railway Record (Industrial Railway Society) 187: 422–423.
- "100 Jahre Rührthaler Maschinenfabrik", a CD by Jens Merte & Martin Schiffmann (Lokrundschau Verlag GmbH, 2001, ISBN 3-931647-12-9))
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- Carrett Marshall & Co., Sun Foundry, Dewsbury Road, Leeds
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- Bagshawe, Peter (2012). Locomotives of the Namaqualand Railway and Copper Mines (1st ed.). Stenvalls. ISBN 978-91-7266-179-0.
- Kerr, Stuart and Company works list
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- H.C. Casserley, Preserved locomotives, 5th edition, Ian Allan, 1980, ISBN 0-7110-0991-0. p.161.
- Bertram Baxter, British Locomotive Catalogue 1825-1923, Vol.1, Moorland Publishing Company, 1977. ISBN 0-903485-50-8.