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 to heat water in the locomotive's boiler to the point where it becomes gaseous and its volume increases 1,700 times. Functionally, it is a steam engine on wheels.
Whyte notation is a classification method for steam locomotives, and some internal combustion locomotives and electric locomotives, by wheel arrangement. It was devised by Frederick Methvan Whyte, and came into use in the early twentieth century following a December 1900 editorial in American Engineer and Railroad Journal.
A 2-8-8-4 steam locomotive, under the Whyte notation, has two leading wheels, two sets of eight driving wheels, and a four-wheel trailing truck. The type was generally named the Yellowstone, a name given it by the first owner, the Northern Pacific Railway, whose lines ran near Yellowstone National Park. Seventy-two Yellowstone-type locomotives were built for four U.S. railroads.
This article is a glossary of the main components found on a typical steam locomotive.
Under the Whyte notation for the classification of steam locomotive wheel arrangements, a 2-10-10-2 is a locomotive with two leading wheels, two sets of ten driving wheels, and a pair of trailing wheels.
In the Whyte notation for the classification of steam locomotive wheel arrangement, a 2-6-6-4 is a locomotive with a two-wheel leading truck, two sets of six driving wheels, and a four-wheel trailing truck. All 2-6-6-4s are articulated locomotives, of the Mallet or related simple articulated type.
A 2-8-8-2, in the Whyte notation for describing steam locomotive wheel arrangements, is an articulated locomotive with a two-wheel leading truck, two sets of eight driving wheels, and a two-wheel trailing truck. The equivalent UIC classification is, refined to Mallet locomotives, (1'D)D1'. These locomotives usually employ the Mallet principles of articulation—with the rear engine rigidly attached to the boiler and the front engine free to rotate—and compounding. The 2-8-8-2 was a design largely limited to American locomotive builders. The last 2-8-8-2 was retired in 1962 from the N&W's roster, two years past the ending of steam though steam was still used on steel mill lines and other railroads until 1983.
Under the Whyte notation for the classification of steam locomotives, a 4-8-8-2 is a locomotive with four leading wheels, two sets of eight driving wheels, and a two-wheel trailing truck.
The 2-6-6-6 is an articulated locomotive type with two leading wheels, two sets of six driving wheels and six trailing wheels. Only two classes of the 2-6-6-6 type were built. One was the "Allegheny" class, built by the Lima Locomotive Works. The name comes from the locomotive's first service with the Chesapeake and Ohio Railway beginning in 1941, where it was used to haul loaded coal trains over the Allegheny Mountains. The other was the "Blue Ridge" class for the Virginian Railway. These were some of the most powerful reciprocating steam locomotives ever built, at 7,500 hp, and one of the heaviest at 386 tons for the locomotive itself plus 215 tons for the loaded tender.
A 2-6-8-0 steam locomotive, in the Whyte notation for describing locomotive wheel arrangements, has two leading wheels, a set of six driving wheels, a set of eight driving wheels, and no trailing wheels. These locomotives usually employ the Mallet principle of articulation, with a swinging front engine and a rigidly attached rear engine.
A Meyer locomotive is a type of articulated locomotive. The design was never as popular as the Garratt or Mallet locomotives. It can be best regarded as 19th Century competition for the early compound Mallet and also the Fairlie articulated designs. Most single cab modern trains are of a similar design such as power cars, freight diesel locomotives, and some passenger locomotives.
A Triplex locomotive is a steam locomotive that divides the driving force on its wheels by using three pairs of cylinders powering three sets of driving wheels. Inevitably any such locomotive will be articulated. All the examples that have been produced were of the Mallet type but with one extra set of driving wheels under the tender.
Southern Railway's Class Ms-2 was a type of experimental steam locomotive.
A duplex locomotive is a steam locomotive that divides the driving force on its wheels by using two pairs of cylinders rigidly mounted to a single locomotive frame; it is not an articulated locomotive. The concept was first used in France in 1863, but was particularly developed in the early 1930s by the Baldwin Locomotive Works, the largest commercial builder of steam locomotives in North America, under the supervision of its then chief engineer, Ralph P. Johnson.
The South African Railways Class KM 0-6-0+0-6-0 of 1904 was an articulated steam locomotive from the pre-Union era in Transvaal Colony.
The South African Railways Class MA 2-6-6-0 of 1909 was a steam locomotive from the pre-Union era in the Natal Colony.
The South African Railways Class MD 2-6-6-2 of 1910 was a steam locomotive from the pre-Union era in Transvaal.
The South African Railways Class ME 2-6-6-2 of 1912 was a steam locomotive.
The South African Railways Class MG 2-6-6-2 of 1911 was a steam locomotive from the pre-Union era in Transvaal.
The Cape Government Railways Kitson-Meyer 0-6-0+0-6-0 of 1903 was a South African steam locomotive from the pre-Union era in the Cape of Good Hope.
