Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles, usually in a leading truck or bogie, eight powered and coupled driving wheels on four axles and no trailing wheels. In North America and in some other countries the type was usually known as the Twelve-wheeler.
Overview The first locomotive is believed to have been the Centipede, a tender locomotive built by Ross Winans in 1855 for the Baltimore and Ohio Railroad in the United States of America, where it remained in service for nearly twenty years. It appears to have been delivered in a cab-forward type of configuration that was modified to a Camel configuration in 1864.Carling, D. Rock (1972). 4-8-0 Tender Locomotives. Drake Publishers Inc. On a Camel locomotive the cab was mounted atop the boiler, unlike the later Camelback locomotive whose cab straddled the boiler which first appeared around 1877.Camelback locomotive – Development
The nickname Mastodon is often mistakenly used to describe the wheel arrangement and was derived from the unofficial name of the first locomotive of the Central Pacific Railroad in the United States, the wood-fired CPR no. 229, which was designed and built in 1882 by the railroad's master mechanic, Andrew Jackson (A.J.) Stevens, at the railroad's Sacramento works in California. However, several period publications instead use the nickname Mastodon to refer to the 4-10-0. These publications refer to the as the Twelve-wheeler.
Usage
Australia The wheel arrangement saw service in Australia from 1900. In Tasmania, the privately owned Emu Bay Railway ordered four tender locomotives for their gauge system. In 1911, another locomotive was delivered from the North British Locomotive Company.North British Locomotive Company works list. (By J. Lambert) Two of these locomotives are preserved.Oberg, Leon. (1975). Locomotives of Australia. Sydney, New South Wales: Reed. p. 157.
A new class of locomotive, the T class, designed in South Australia for use on the narrow gauge gauge system of the South Australian Railways, was introduced in 1903. It proved to be a suitable workhorse and by 1917 there were 78 locomotives in the class. In 1921 and 1922, the Tasmanian Government also purchased six of these narrow gauge South Australian locomotives and, during 1922 and 1923, five of the class were converted to gauge for use on the broad gauge system of the South Australian. These were converted back to narrow gauge in 1949. During the Second World War, the Commonwealth Railways obtained four of these South Australian narrow gauge locomotives on loan. Several of these locomotives are preserved.
The Queensland Government Railways (QGR) introduced its C16 class of locomotives in 1903, built at its Ipswich workshops. Altogether 152 of these locomotives were in service by 1917. Beginning in 1920, a number of the QGR C16 class locomotives were equipped with superheaters on an experimental basis, but since their slide valves were not suited to superheated steam and became prone to steam leaks due to excessive wear, they were soon converted back to use saturated steam. During the Second World War, the Commonwealth Government also acquired eleven C16 class locomotives on loan. Only one example of this class was preserved.
The QGR's superheated C17 class entered service from 1920. The Commonwealth Railways also ordered 22 locomotives of the same design for their narrow gauge rail system, designated the NM class. In total, the C17 class eventually numbered 227 locomotives, of which twenty are preserved.
In 1922, the QGR ordered 22 new locomotives and designated them the C19 class. They were the largest conventional-type locomotives to operate on the QGR.
Austria In Austria, the wheel arrangement was used for express locomotives. The Class 570 locomotive was introduced in 1915 and the class 113 locomotive of the Austrian Federal Railways was introduced in 1923. From 1938, both classes were re-designated as Class 33 on the Deutsche Reichsbahn.
Bechuanaland In 1897, four Cape 7th Class locomotives were ordered by the Cape Government Railways (CGR) from Neilson and Company for use on the new Vryburg to Bulawayo line of the fledgling Bechuanaland Railway Company (BR). The line through Bechuanaland Protectorate was still under construction and was operated by the CGR on behalf of the BR at the time. The locomotives were eventually returned to the CGR and were designated Class 7A on the South African Railways in 1912.
France
In France, the wheel arrangement was used on two locomotive classes. The first was in 1907 by the Chemins de fer de Paris à Lyon et à la Méditerranée (PLM). These locomotives were intended for goods trains, as well as passenger trains on the more difficult routes. They were Baudry type compound locomotives, similar to the De Glehn type, but with their low pressure cylinders set at 60% cut-off. All of them originally used saturated steam, but some were later equipped with superheaters while all the others were provided with feedwater heaters. These locomotives had a maximum speed limit of and were designed to be able to haul at . A total of 282 were built. The PLM had prepared designs for another much larger locomotive by 1913, but it did not materialise as a result of the outbreak of the First World War.
The second locomotive to appear in France was the famous 240P class of the Société Nationale des Chemins de Fer Français (SNCF), with "240" in this instance referring to the French classification of wheel arrangement according to the number and arrangement of axles rather than wheels. Technically, these locomotives were developments of some of the earliest Pacific locomotives in Europe that were built for the Chemin de Fer de Paris à Orléans (PO). The 240P class was considered to be one of André Chapelon's finest designs and benefited from his thorough understanding of thermodynamics and his appreciation of the need to consider the entirety of the steam circuit. The locomotive was a four-cylinder compound, fitted with Lentz-Dabeg poppet valves.
Coupled with an elegant French style tender, the second batch of the 240P class was aesthetically much more pleasing. With a power output of , the 240P class was reputed to have the highest power-to-weight ratio of any steam locomotive. Discussion continues as to how robust they were mechanically, for example whether the size of the bearings was too near the bone, or whether they were simply worked to death during the difficult war years. None have survived in preservation.
Hungary
In the 1920s, the Magyar Államvasutak (Hungarian State Railways or MÁV) adopted the type as their standard mixed-traffic locomotive in the shape of the 424 class, which was built between 1924 and 1958. Of these, 365 were built for Hungary and 149 for foreign systems, including the Yugoslav Railways, the Soviet Union and North Korea. In Yugoslavia, they were designated the Jugoslovenske Železnice (JŽ) class 11. The last of the Hungarian locomotives were withdrawn from service in 1984.
Ireland For a short period, the Great Southern and Western Railway in Ireland and its successor, the Great Southern Railways, operated two inside-cylinder shunting locomotives. Intended for shunting at Dublin Kingsbridge (now Heuston) and for banking on the steep gradient out of Cork Glanmire Road (now Kent), the first locomotive emerged from the company's Inchicore workshops in 1915 and the second in 1924. They proved unsuccessful, being expensive to operate and unsuitable for sharp curves, and were withdrawn in 1928 and 1931 respectively.
On the Irish three-foot gauge, the Londonderry and Lough Swilly Railway operated two tender locomotives. Built by Hudswell Clarke, they were introduced in 1905 and withdrawn in the 1930s and 1940s. The two were the only tender locomotives ever to operate on that gauge in Ireland and, with two subsequent tank engines from the same manufacturer, were considered to be the most powerful which ever worked on any Irish narrow-gauge railway.
Mexico 4-8-0 locomotives in Mexico were almost entirely built in the United States. The first locomotives were provided by the Southern Pacific Railroad to independent and subsidiary railroads such as the Cananae, Rio Yaqui & Pacifico and Sud Pacifico de Mexico. The Sud Pacifico de Mexico used, in total, 14 of the Southern Pacific's 4-8-0s, including a few from CRY&P, all constructed at Schenectady between 1889 and 1895.
The National Railways of Mexico had four classes of 4-8-0. The first two orders were relatively small locomotives from Brooks in 1897. In 1924, a much larger locomotive was ordered, the PR-7, numbers 5-A to 2856 and weighing 127 tons. Unusually among American-built 4-8-0s, these were intended for express passenger service and therefore had much larger drivers than 4-8-0s operating in the United States, at 67 inches diameter. The cylinders had an unusually square bore and stroke of 28 x 28 inches. Because the firebox was wide and above the frames, the tops of the last set of drivers projected into the firebox, something which was only possible due to them being oil fired.
In 1935, a further five locomotives were built with larger boilers, which increased the evaporative heating surface by 357 square feet and the superheater surface by 172 square feet. These were designated PR-8, numbers 3000 to 3004. At 144 tons, the PR-8 was the heaviest conventional 4-8-0 ever built. The Norfolk & Western's M2, which is often credited as being the heaviest conventional 4-8-0, weighed less than the PR-8.
New Zealand
New Zealand's first locomotive was built in the Addington Railway Workshops of the New Zealand Railways Department (NZR) in 1899 and designated B class. Four more were completed that same year and one more in 1901, while Sharp, Stewart & Company built four more over the next two years.
Ten BA class locomotives were built by the NZR at its Addington shops between 1911 and 1913, and thirty BB class locomotives were built by A&G Price in New Zealand between 1915 and 1918. One each of the BA class and BB class have been preserved, BA no. 552 and BB no. 144. Both are in Auckland at the Parnell Depot of Mainline Steam, an organisation devoted to the restoration and operation of historic New Zealand Railways mainline steam locomotives.
Poland
The only 4-8-0 locomotives in polish service, were Os24. They were based on Austrian Class 570 and built in years 1925 - 1927. Their first purpose was operating express services in central and eastern Poland. Os24 turned out to be unreliable locomotives, which resulted in reduction of ordered units. Among their major issues, machines had problems with snaking, stability installation malfunctions and even with breaking wheels and frames. 60 built locomotives were located in eastern depots, like Lublin, Wilno, Białystok, etc. (situation in late 1938).B. Prokopiński, Parowozy normalotorowe produkcji polskiej, Warsaw 2020, p. 80. It caused that majority of locomotives during WWII have been captured by USSR. After 1945 only 15 units returned to Poland. Their service ended in until 1970. Today the only surviving Os24 is stored in Stacja Muzeum in Warsaw. Locomotive was built in 1926 in Fablok.
Rhodesia