A Mallet locomotive is a type of compound articulated steam locomotive, invented by the Swiss engineer Anatole Mallet (1837–1919).
Under the Whyte notation for the classification of steam locomotives, 4-6-2 represents the wheel arrangement of four leading wheels on two axles, six powered and coupled driving wheels on three axles and two trailing wheels on one axle. The 4-6-2 locomotive became almost globally known as a Pacific type after a New Zealand locomotive that was shipped across the Pacific Ocean.
0-6-0 is the Whyte notation designation for steam locomotives with a wheel arrangement of no leading wheels, six powered and coupled driving wheels on three axles, and no trailing wheels. Historically, this was the most common wheel arrangement used on both tender and tank locomotives in versions with both inside and outside cylinders.
Under the Whyte notation for the classification of locomotives, 4-6-4 represents the wheel arrangement of four leading wheels, six powered and coupled driving wheels and four trailing wheels. In France where the type was first used, it is known as the Baltic while it became known as the Hudson in most of North America.
The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle. It can also serve as a reversing gear. It is sometimes referred to as the "motion".
Under the Whyte notation for the classification of steam locomotives, 2-10-2 represents the wheel arrangement of two leading wheels, ten powered and coupled driving wheels, and two trailing wheels. In the United States and elsewhere the 2-10-2 is known as the Santa Fe type, after the Atchison, Topeka and Santa Fe Railway that first used the type in 1903.
4-4-0 is a locomotive type with a classification that uses the Whyte notation for the classification of steam locomotives by wheel arrangement and represents the arrangement: four leading wheels on two axles, four powered and coupled driving wheels on two axles, and a lack of trailing wheels. Due to the large number of the type that were produced and used in the United States, the 4-4-0 is most commonly known as the American type, but the type subsequently also became popular in the United Kingdom, where large numbers were produced.
A 4-6-0 steam locomotive, under the Whyte notation for the classification of steam locomotives by wheel arrangement, has four leading wheels on two axles in a leading bogie and six powered and coupled driving wheels on three axles with the absence of trailing wheels.
Under the Whyte notation for the classification of steam locomotives, 2-8-0 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, eight powered and coupled driving wheels on four axles, and no trailing wheels. In the United States and elsewhere, this wheel arrangement is commonly known as a Consolidation, after the Lehigh and Mahanoy Railroad’s Consolidation, the name of the first 2-8-0.
Under the Whyte notation for the classification of steam locomotives, 2-8-2 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, eight powered and coupled driving wheels on four axles and two trailing wheels on one axle, usually in a trailing truck. This configuration of steam locomotive is most often referred to as a Mikado, frequently shortened to Mike.
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 4-4-2 represents a configuration of a four-wheeled leading bogie, four powered and coupled driving wheels, and two trailing wheels supporting part of the weight of the boiler and firebox. This allows a larger firebox and boiler than the 4-4-0 configuration.
A 4-4-4-4 steam locomotive, in the Whyte notation for describing locomotive wheel arrangements, has a four-wheel leading truck, two sets of four driving wheels, and a four-wheel trailing truck. While it would be possible to make an articulated locomotive of this arrangement, the only 4-4-4-4s ever built were duplex locomotives—with two sets of cylinders driving two sets of driven wheels in one rigid frame, essentially a 4-8-4 with divided drive.
Under the Whyte notation for the classification of steam locomotives, 0-4-2 represents the wheel arrangement with no leading wheels, four powered and coupled driving wheels on two axles and two trailing wheels on one axle. While the first locomotives of this wheel arrangement were tender engines, the configuration was later often used for tank engines, which is noted by adding letter suffixes to the configuration, such as 0-4-2T for a conventional side-tank locomotive, 0-4-2ST for a saddle-tank locomotive, 0-4-2WT for a well-tank locomotive and 0-4-2RT for a rack-equipped tank locomotive.
Under the Whyte notation for the classification of steam locomotives, a 0-6-6-0 wheel arrangement refers to a locomotive with two engine units mounted under a rigid locomotive frame, with the front engine unit pivoting and each engine unit with six coupled driving wheels without any leading or trailing wheels. The wheel arrangement was mostly used to describe Mallet locomotive types.
Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 2-6-6-0 is a locomotive with one pair of unpowered leading wheels, followed by two sets of three pairs of powered driving wheels and no trailing wheels. The wheel arrangement was principally used on Mallet-type articulated locomotives. Some tank locomotive examples were also built, for which various suffixes to indicate the type of tank would be added to the wheel arrangement, for example 2-6-6-0T for an engine with side-tanks.
The Great Western Railway (GWR) 4575 Class is a class of 2-6-2T British steam locomotives.
Manning Wardle was a steam locomotive manufacturer based in Hunslet, Leeds, West Yorkshire, England.
The London and North Eastern Railway (LNER) Class K1 is a type of 2-6-0 (mogul) steam locomotive designed by Edward Thompson. Thompson preferred a simple two-cylinder design instead of his predecessor Nigel Gresley's three-cylinder one. The seventy K1s were intended to be split between the North Eastern Region of British Railways and the Eastern Region of British Railways.
The Russian locomotive class U was a Russian express passenger steam locomotive type. The class U was a 4-6-0 four-cylinder compound locomotive which used de Glehn compound system.
The China Railways JF2 class steam locomotive was a class of 2-8-2 steam locomotives for goods trains operated by the China Railway. They were originally built for the South Manchuria Railway (Mantetsu) by several American and Japanese manufacturers, as well as by Mantetsu's Shahekou Works, between 1924 and 1932.
