The wheel arrangement 2-8-0 stands for a locomotive with one leading axle and four driven axles. The following designations exist in the different naming systems:
Consolidation
UIC: 1'D
Whyte: 2-8-0
Switzerland: 4/5
France: 140
Turkey: 45
The 2-8-0 can mainly be seen as a 2-6-0 “Mogul” that has been enlarged with an additional driving axle for increased traction and a bigger boiler. Historically, many 2-8-0 were also created by either adding a leading axle to a 0-8-0 or by building them new on the basis of a 0-8-0 design that has been modified with a leading axle. While the leading axle also carried a bit more weight and allowed to fit a somewhat larger boiler, its main purpose was to guide the locomotive at higher speeds.
The first locomotive with this wheel arrangement was created in 1863 by rebuilding an 0-8-0 of the PRR. But this one had a fixed leading axle and could not be viewed as a real Consolidation. The first one with a flexible leading axle in a Bissel truck was built by Baldwin in 1866 for the Lehigh and Mahanoy Railroad. It had been designed by Alexander Mitchell and was named “Consolidation”, what created the name for this wheel arrangement that was not only used in the USA, but all around the world.
The breakthrough for the Consolidation came in 1875 when the PRR made the class I their standard freight locomotive. In the following years, they built more than 500 in their own Juniata shops at Altoona. Compared to a 4-4-0 locomotive, they could haul double the weight at lower operating costs. Their large number and their ability to haul 80 to 90 cars at a modest speed also showed other operators that the Consolidation was the freight locomotive of the future.
In total, US builders completed around 23,000 Consolidations, of which 11,000 were for US customers. Among the locomotives built for export were thousands which were intended for service with the US Army Transportation Corps in other countries. These were the “Pershing” built by Baldwin in World War I and the S160 built by all three major US builders in World War II. They also built many Consolidations for other countries which were in need after the wars, like 400 for Italy after World War I and 300 for Belgium after World War II.
In the UK, it took until the 20th century until the 2-8-0 became the standard for heavy freight service, in addition to the 0-6-0 that was still used for most tasks. It won against the 0-8-0 due to its better running characteristics. While the GWR class 2800 was the first new built locomotive of this wheel arrangement in Britain in 1905, George Whale of the LNWR rebuilt 0-8-0 locomotives to 2-8-0. In World War I, more than 500 standard 2-8-0 locomotives were built for the Railways Operating Division, as was the case with more than 900 War Department Austerity 2-8-0 locomotives in World war II. Meanwhile, Stanier had designed the 8F for the LMS, what was the freight variant of the “Black Five” and what was built 852 times.
Another country that operated lots of Consolidations from domestic and foreign builders was the Russian Empire. After 477 locomotives of the type Р (R), they made the Щ (Shcha) their standard freight locomotive in 1906 and ordered 1,910. Most of both types were built as four- and two-cylinder compounds. Japan ordered their first Consolidations in 1893 from the USA and later built 770 members of the class 9600 in their own country from 1913.
French railways used hundreds of locomotives of this wheel arrangement. A powerful example was the “Le Boeuff” of the Nord, what was a superheated four-cylinder compound. In Germany, the 2-8-0 was only successful in the Länderbahn era. When the Reichsbahn was founded in the 1920s, they quickly decided to make the 2-10-0 their standard freight type. Finland first ordered the 2-8-0 from the USA, but later operated many which were built in Finland or by other European builders.
With increasing train weights and the need to increase the speed at the same time, the main problem of the 2-8-0 was that it did not have much space to fit a wide firebox. Although the boiler could be mounted high to fit a wide firebox above the drivers, this was complicated with a powerful large diameter boiler. It finally had to give way to locomotives with a trailing truck like the 2-8-2 “Mikado” that had a large firebox, creating more steam at speed. Today a large number of preserved standard and narrow gauge Consolidations is still running in various countries.