Under the Whyte notation for the classification of

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...

s, 2-2-2-0 usually represents the wheel arrangement of two leading wheels on one axle, four powered but uncoupled

driving wheel On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons (or turbine, in the case of a steam turbine locomotive). On a conventional, non-articulated locomotive, the driving wheels are all coupled ...

s on two axles, and no trailing wheels, but can also be used to represent two sets of leading wheels (not in a

bogie A bogie ( ) (in some senses called a truck in North American English) is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transp ...

truck) two

s, and no trailing wheels. Some authorities place brackets around the duplicated but uncoupled wheels, creating a notation 2-(2-2)-0, or (2-2)-2-0, as a means of differentiating between them. Others simply refer to the locomotives 2-2-2-0.

Usage

The 2-2-2-0 wheel arrangement was first used on some locomotives introduced on the Eastern Counties Railway by John Chester Craven between 1845 and 1847, and some Crampton locomotives on the South Eastern Railway in 1849.Baxter, (1977) pp.45 & 67. However the 2-2-2-0 type is usually associated with Francis Webb of the

London and North Western Railway The London and North Western Railway (LNWR, L&NWR) was a British railway company between 1846 and 1922. In the late 19th century, the L&NWR was the largest joint stock company in the United Kingdom. In 1923, it became a constituent of the Lo ...

who between 1882 and 1890 introduced a number of compound locomotive classes including the LNWR Webb Experiment Class, LNWR Dreadnought Class and LNWR Teutonic Class. The locomotives were never reliable and Webb's successor George Whale withdrew them all within three years of taking up office in 1903, The type was used with more success on French railways with a 4-cylinder compound locomotive designed by Alfred de Glehn, of the Société Alsacienne de Constructions Mécaniques (SACM) in 1886. Later examples were of the

4-2-2-0 Under the Whyte notation for the classification of steam locomotives, 4-2-2-0 represents the wheel arrangement of four leading wheels on two axles, four powered but uncoupled driving wheels on two axles, and no trailing wheels. The arrangement beca ...

configuration.

References

{{Whyte types

2-2-2-0 Under the Whyte notation for the classification of steam locomotives, 2-2-2-0 usually represents the wheel arrangement of two leading wheels on one axle, four powered but uncoupled driving wheels on two axles, and no trailing wheels, but can also be ...