Whyte notation

Whyte Notation

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Whyte notation

The Whyte notation for classifying steam locomotive

Steam locomotive

A steam locomotive is a locomotive powered by steam. The term usually refers to its use on railways, but can also refer to a "road locomotive" such as a traction engine or steamroller....
s by wheel arrangement

Wheel arrangement

In rail transport a wheel arrangement is a system of classifying the arrangement of the bogie of a locomotive by type, position, and connections....
was devised by Frederick Methvan Whyte

Frederick Methvan Whyte

Frederick Methvan Whyte was a mechanical engineer of Netherlands background who worked for the New York Central in the United States. He is most widely known as the person who developed Whyte notation to describe the different wheel arrangements of steam locomotives in 1900....
and came into use in the early Twentieth Century encouraged by an editorial in American Engineer and Railroad Journal (December 1900). Whyte's system counts the number of leading wheel

Leading wheel

The leading wheel or leading axle of a steam locomotive is an unpowered wheel or axle located in front of the driving wheels. The axle or axles of the leading wheels are normally located in a truck ....
s, then the number of driving wheel

Driving wheel

On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons . On a conventional, non-articulated locomotive, the driving wheels are all coupled together with side rods ; normally one pair is directly driven by the main rod which is connected to the end of the piston rod; power is transmitted to th...
s, and finally the number of trailing wheel

Trailing wheel

On a steam locomotive, a trailing wheel or trailing axle is generally an unpowered wheel or axle located behind the driving wheels. The axle of the trailing wheels were usually located on a trailing Bogie....
s, groups of numbers being separated by dashes.

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Encyclopedia

The Whyte notation for classifying steam locomotive

Steam locomotive

Wheel arrangement

In rail transport a wheel arrangement is a system of classifying the arrangement of the bogie of a locomotive by type, position, and connections....
was devised by Frederick Methvan Whyte

Frederick Methvan Whyte

Leading wheel

Driving wheel

Trailing wheel

UIC classification

The International Union of Railways classification is a comprehensive system for describing the wheel arrangement of locomotives, multiple units and trams....
and the French, Turkish and Swiss systems for steam locomotives, count axles rather than wheels.

Thus, a locomotive with two leading axle

Axle

An axle is a central shaft for a rotation wheel or gear. In some cases the axle may be fixed in position with a bearing or bushing sitting inside the hole in the wheel or gear to allow the wheel or gear to rotate around the axle....
s (and thus four wheels) in front, then three driving axles (six wheels) and followed by one trailing axle (two wheels) is classified as a 4-6-2

4-6-2

Under the Whyte notation for the classification of steam locomotives, a 4-6-2 locomotive has four leading wheels , six coupled driving wheels and two trailing wheels ....
.

Method

Articulated locomotives

Articulated locomotive

Articulated locomotive usually means a steam locomotive with one or more engine units which can move relative to the main frame. This is done to allow a longer locomotive to negotiate tighter curves....
s such as Garratt

Garratt

A Garratt is a type of steam locomotive that is articulated locomotive in three parts. Its boiler is mounted on the centre frame, and two steam engines are mounted on separate frames, one on each end of the boiler....
s, which are effectively two locomotives joined by a common boiler

Boiler

A boiler is a closed Pressure vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications....
, have a + between the arrangements of each engine. Thus, a 'double Pacific' type Garratt is a 4-6-2+2-6-4.

Simpler articulated types such as Mallets, where there are no unpowered axles between powered axles, have extra groups of numbers in the middle. Thus a Big Boy

Union Pacific Big Boy

Big Boy was the name given to the Union Pacific Railroad's twenty-five 4000 class 4-8-8-4 articulated steam locomotives built between 1941 and 1944 by American Locomotive Company....
is a 4-8-8-4; there are two leading axles, one group of four driving axles, another group of four driving axles, and then two trailing axles.

Suffixes

The suffix T indicates a tank locomotive

Tank locomotive

A tank locomotive is a steam locomotive that carries its own fuel and water on it, instead of pulling it behind it in a tender locomotive....
; otherwise, a tender locomotive

Tender locomotive

Steam locomotives often haul a tender, which is a special railway truck designed to hold the locomotive's fuel and water. In America, tenders are sometimes called coal-cars....
is assumed. In British practice, this is sometimes extended to indicate the type of tank locomotive: T means side tank, PT pannier tank, ST saddle tank

Saddle tank

Saddle tank may refer to:* Saddle tank , a water tank carried above the boiler of a steam locomotive; also the type name of a locomotive so fitted....
, WT well tank. T+T means a tank locomotive that has a tender for additional coal or water capacity.

In Europe, the suffix R could mean rack (0-6-0RT) or it could mean reversible (0-6-0TR). The latter case being the Bi-cabine locomotives used in France.

The suffix F indicates a fireless locomotive

Fireless locomotive

A fireless locomotive is a type of locomotive designed for use under conditions restricted by either the presence of flammable material or the need for cleanliness ....
(0-4-0F). Note that this locomotive has no tender.

Other suffixes have been used at times, including ng for narrow-gauge locomotives (i.e., less than 56.5 in / 1435 mm) and CA or ca for compressed air (i.e., running on compressed air from a tank instead of steam).

Internal combustion locomotives

In Britain, small diesel and petrol

Gasoline

File:GasCan.jpgGasoline or petrol is a petroleum-derived liquid mixture, primarily used as fuel in internal combustion engines.It consists mostly of aliphatic hydrocarbons, enhanced with iso-octane or the aromatic hydrocarbons toluene and benzene to increase its octane rating....
locomotives are usually classified in the same way as steam locomotives, e.g. 0-4-0, 0-6-0, 0-8-0. This may be followed by D for diesel, P petrol, and another letter describing the transmission: E for electric, H hydraulic, M mechanical. Thus 0-6-0DE denotes a six-wheel diesel locomotive with electric transmission. Where the axles are coupled by chains or shafts (rather than side-rods), or are individually driven, the terms 4w, 6w or 8w are generally used. Thus 4wPE indicates a four-wheel petrol locomotive with electric transmission. For large diesel locomotives the UIC classification

UIC classification

The International Union of Railways classification is a comprehensive system for describing the wheel arrangement of locomotives, multiple units and trams....
is used.

Limitations

The limitations of the Whyte system in classifying locomotives that did not fit the standard steam locomotive pattern led to the design of other forms of classification. Most commonly used in Europe is the UIC classification

UIC classification

The International Union of Railways classification is a comprehensive system for describing the wheel arrangement of locomotives, multiple units and trams....
scheme, based on German

Germany

Germany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium, and the Netherlands....
practice, which can more completely define the exact layout of a locomotive.

Naming

In American

United States

The United States of America is a Federal government constitutional republic comprising U.S. state and a federal district. The country is situated mostly in central North America, where its Contiguous United States and Washington, D.C., the Capital districts and territories, lie between the Pacific Ocean and Atlantic Oceans, Borders of the U...
(and to a lesser extent British

United Kingdom

The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom , the UK or Britain,is a sovereign state located off the northwestern coast of continental Europe....
) practice, most wheel arrangements in common use were given names, often from the name of the first such locomotive built. (For example, the 2-2-0 is named Planet.) (This naming convention is reminiscent of the naming of warship

Warship

A warship is a ship that is built and primarily intended for combat. Warships are usually built in a completely different way than cargo ship....
classes.)

Common wheel arrangements

Here is a list of the most common wheel arrangements: in the illustration the front of the locomotive is to the left.

Arrangement (locomotive front is to the left)	Whyte classification	Name

Non-articulated locomotives

	0-2-2 0-2-2 An 0-2-2, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is one that has two coupled driving wheels followed by two trailing wheels, with no leading wheels ....	Northumbrian
	2-2-0 2-2-0 A 2-2-0, in the Whyte notation for the classification of steam locomotives by wheel arrangement, has one unpowered leading axle and one powered driving axle....	Planet
	2-2-2 2-2-2 Under the Whyte notation for the classification of locomotive#Steam, a 2-2-2 locomotive has two leading wheels, two driving wheels and two trailing wheels....	Single, Jenny Lind
	2-2-4 2-2-4 In Whyte notation, a 2-2-4 is a railroad steam locomotive that has two leading wheels followed by two coupled driving wheels and four trailing wheels....
	4-2-0 4-2-0 In the Whyte notation, a 4-2-0 is a railroad steam locomotive that consists of a 4-wheel leading truck followed by a single driving axle. This type of locomotive, often called a Jervis type, was common on United States railroads from the 1830s through the 1850s....	Jervis
	4-2-2 4-2-2 Under the Whyte notation for the classification of steam locomotives, a 4-2-2 locomotive has four leading wheels, two driving wheels and two trailing wheels....	Bicycle
	4-2-4 4-2-4 (locomotive) In Whyte notation, a 4-2-4 is a steam locomotive that has a four-wheel leading truck, one powered driving wheel and a four-wheel unpowered trailing truck....
	6-2-0 6-2-0 In the Whyte notation, a 6-2-0 is a railroad steam locomotive that has an unpowered three-axle leading truck followed by a single powered driving axle....	Crampton

	0-4-0 0-4-0 Under the Whyte notation for the classification of steam locomotives, 0-4-0 represents one of the simplest possible types, that with two axles and four wheels, all of which are driven....	Four-Coupled
	0-4-2 0-4-2 In Whyte notation, a 0-4-2 is a railroad steam locomotive that has four coupled driving wheels followed by two trailing wheels, with no leading wheels....
	0-4-4 0-4-4 In Whyte notation, an 0-4-4 is a railroad steam locomotive that has four coupled driving wheels followed by four trailing wheels, with no leading wheels....	Forney
	2-4-0 2-4-0 In Whyte notation, a 2-4-0 is a railroad steam locomotive that has two leading wheels followed by two coupled driving wheels, with no trailing wheels....	Porter
	2-4-2 2-4-2 In the Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-4-2 has two leading wheels, four driving wheels and two trailing wheels....	Columbia
	2-4-4 2-4-4 File:WheelArrangement 2-4-4.svgIn Whyte notation, a 2-4-4 is a steam locomotive with two unpowered leading wheels followed by four powered driving wheels and four unpowered trailing wheels....
	4-4-0 4-4-0 A 4-4-0 is a type of steam locomotive. In the Whyte notation, 4-4-0 signifies that it has a two-axle bogie to help guide it into curves, and two driving axles coupled by a connecting rod....	American, Eight-wheeler
	4-4-2 4-4-2 (locomotive) In the Whyte notation a 4-4-2 is a steam locomotive that has a two-axle leading truck, two powered driving axles and a one-axle trailing truck....	Atlantic
	4-4-4 4-4-4 A 4-4-4, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is one with four leading wheels, four coupled driving wheels , and four trailing wheels....	Reading, Jubilee (Canada)

	0-3-0 0-3-0 Four locomotives were built with this wheel arrangement in 1909 for the Patiala State Monorail Trainways, a monorail line in Patiala, India. They had double flanged driving wheels and the locomotives had an outrigger wheel that ran on the ground....	(one driving wheel per axle; used on Patiala State monorail and also on the Listowel and Ballybunion Railway)
	0-6-0 0-6-0 The term 0-6-0 is the Whyte notation for the wheel arrangement of a locomotive with six powered driving wheels , and neither leading nor trailing wheels....	Six-Coupled, Bourbonnais (France), USRA 0-6-0 USRA 0-6-0 The USRA 0-6-0 was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I.... (United States)
	0-6-2 0-6-2 In Whyte notation, a 0-6-2 is a railroad steam locomotive that has six coupled driving wheels followed by two trailing wheels, with no leading wheels....
	0-6-4 0-6-4 In Whyte notation, a 0-6-4 is a railroad steam locomotive that has six coupled driving wheels followed by four trailing wheels, with no leading wheels....	Forney six-coupled
	2-6-0 2-6-0 In the Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-6-0 has a pair of leading wheels followed by six driving wheels....	Mogul
	2-6-2 2-6-2 Under the Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-6-2 has two leading wheels, six coupled driving wheels, and two trailing wheels....	Prairie
	2-6-4 2-6-4 Under the Whyte notation for the classification of steam locomotives, a 2-6-4 locomotive has two leading wheels, six coupled driving wheels and four trailing wheels....	Adriatic
	2-6-6 2-6-6 In the Whyte notation for describing steam locomotive wheel arrangement, a 2-6-6 is a locomotive with a two-wheeled leading truck, six driving wheels, and a six-wheeled trailing truck....
	4-6-0 4-6-0 In the Whyte notation, a 4-6-0 is a railroad steam locomotive that has a two-axle leading truck followed by three driving axles. This wheel arrangement became the second-most popular configuration for new steam locomotives in United States in the mid-19th century....	Ten-Wheeler (not Britain)
	4-6-2 4-6-2 Under the Whyte notation for the classification of steam locomotives, a 4-6-2 locomotive has four leading wheels , six coupled driving wheels and two trailing wheels ....	Pacific
	4-6-4 4-6-4 A 4-6-4 locomotive, in the Whyte notation for the classification of steam locomotives, has four leading wheels , six coupled driving wheels and four trailing wheels ....	Hudson, Baltic

	0-8-0 0-8-0 In the Whyte notation for the wheel arrangement of locomotives , an 0-8-0 is a locomotive with eight powered driving wheels , and neither leading wheels or trailing wheels....	Eight-Coupled, USRA 0-8-0 USRA 0-8-0 The USRA 0-8-0 was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I.... (United States)
	0-8-2 0-8-2 An 0-8-2, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with no leading wheels, eight driving wheels fixed in a rigid frame, and two trailing wheels ....
	0-8-4 0-8-4 An 0-8-4, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with no leading wheels, eight driving wheels fixed in a rigid frame, and four trailing wheels ....
	2-8-0 2-8-0 In the Whyte notation, a 2-8-0 is a railroad steam locomotive that has a single-axle leading truck followed by four powered driving axles. In the US, this wheel arrangement is commonly called a Consolidation....	Consolidation
	2-8-2 2-8-2 In the Whyte notation, a 2-8-2 is a railroad steam locomotive that has one leading axle followed by four powered driving wheel and one trailing axle....	Mikado, Mike, MacArthur
	2-8-4 2-8-4 In the Whyte notation, a 2-8-4 is a railroad steam locomotive that has one unpowered leading axle followed by four powered driving axles and two unpowered trailing axles....	Berkshire, Kanawha
	2-8-6 2-8-6 In the Whyte notation for describing steam locomotive wheel arrangement, a 2-8-6 is a locomotive with a two-wheel leading truck, eight driving wheels, and a six-wheel trailing truck....	Used only on four Mason Bogie Mason Bogie The Mason Bogie is a type of articulated steam locomotive suited for sharp curves and uneven track, once commonly used on narrow gauge railway lines in the United States.... locomotives
	4-8-0 4-8-0 Under the Whyte notation for the classification of steam locomotives, a 4-8-0 locomotive has four leading wheels, eight coupled driving wheels and no trailing wheels....	Mastodon, Twelve-Wheeler
	4-8-2 4-8-2 Under the Whyte notation for the classification of steam locomotives, a 4-8-2 locomotive has four leading wheels , eight coupled driving wheels and two trailing wheels ....	Mountain, Mohawk
	4-8-4 4-8-4 Under the Whyte notation for the classification of steam locomotives, a 4-8-4 locomotive has four leading wheels, eight coupled driving wheels and four trailing wheels....	Northern, Niagara, Confederation, Dixie, Greenbrier, Pocono, Potomac, Golden State, Western, General, Governor, Big Apple, GS Series "Daylight" Southern Pacific class GS-4 The GS-4 was a streamlined 4-8-4 Northern type steam locomotive that served the Southern Pacific Railroad from 1941 to 1958. They were built by the Lima Locomotive Works and were numbered 4430 through 4457.... (Southern Pacific)
	4-8-6 4-8-6 Under the Whyte notation for the classification of steam locomotives, a 4-8-6 locomotive would have had four leading wheels, eight coupled driving wheels and six trailing wheels....	Proposed by Lima Lima Locomotive Works Lima Locomotive Works was an American firm that manufactured railroad locomotives from the 1870s through the 1950s. The company took the most distinctive part of its name from its main shops location in Lima, Ohio.... , never built
	6-8-6 6-8-6 In Whyte notation a 6-8-6 is a steam locomotive with six unpowered leading wheels arranged into a three-axle leading truck, eight powered driving wheels, and six unpowered trailing wheels arranged into a three-axle trailing truck....	(PRR S2 PRR S2 The Pennsylvania Railroad's class S2 was a steam turbine locomotive. Only one prototype was built, #6200, delivered in 1944. The S2 was the sole example of the 6-8-6 wheel arrangement in the Whyte notation, featuring a six-wheel leading truck, eight driving wheels, and a six-wheel trailing truck.... steam turbine Steam turbine A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion. Its modern manifestation was invented by Charles Algernon Parsons in 1884.... locomotive)

	0-10-0 0-10-0 In the Whyte notation for the classification of steam locomotive wheel arrangement, an 0-10-0 is a locomotive with ten driving wheels and neither leading nor trailing wheels....	Ten-Coupled, (rarely) Decapod
	0-10-2 0-10-2 An 0-10-2, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with no leading wheels at all, ten driving wheels, and a two-wheel trailing truck....	Union
	2-10-0 2-10-0 Under the Whyte notation for the classification of steam locomotives, a 2-10-0 is a locomotive with two leading wheels, generally in a radially swinging leading truck, and ten coupled driving wheels, five on each side....	Decapod, Russian Decapod
	2-10-2 2-10-2 A 2-10-2 steam locomotive in the Whyte notation for wheel arrangements has two leading wheels , ten driving wheels , and two trailing wheels . In the United States, the 2-10-2 is known as the Santa Fe type, after the railroad "Atchison, Topeka and Santa Fe Railway" that first used the type in 1903....	Santa Fe, Central, Decapod (only on the Southern Pacific)
	2-10-4 2-10-4 Under the Whyte notation for the classification of steam locomotives, a 2-10-4 locomotive has two leading wheels, ten driving wheels , and four trailing wheels....	Texas, Colorado Colorado The State of Colorado is a U.S. state located in the Mountain States of the United States of America. Colorado may also be considered to be a part of the Western United States and Southwestern United States regions of the United States.... (CB&Q), Selkirk (Canada)
	4-10-0 4-10-0 Under the Whyte notation for the classification of steam locomotives, a 4-10-0 locomotive has four leading wheels followed by ten driving wheels, with no trailing wheels....	Mastodon, Gobernador (in honor of El Gobernador El Gobernador *El Gobernador* was a 4-10-0 steam locomotive built by Central Pacific Railroad at the railroad's Sacramento, California Sacramento Railyards.... )
	4-10-2 4-10-2 Under the Whyte notation for the classification of steam locomotives, a 4-10-2 locomotive has four leading wheels, ten driving wheels and two trailing wheels....	Southern Pacific Southern Pacific Railroad The Southern Pacific Transportation Company , earlier Southern Pacific Railroad and Southern Pacific Company , was an United States railroad.... , Overland

	0-12-0 0-12-0 In Whyte notation, a 0-12-0 is a railroad steam locomotive that has twelve coupled driving wheels, with no leading wheels or trailing wheels.Other equivalent classifications are:...	Twelve-Coupled
	2-12-0 2-12-0 In Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-12-0 is a locomotive with one pair of unpowered leading wheels, followed by six pairs of powered driving wheels, and no trailing wheels....	Centipede
	2-12-2 2-12-2 Under the Whyte notation for the classification of steam locomotives, a 2-12-2 locomotive has two leading wheels, twelve driving wheels and two trailing wheels....	Javanic
	2-12-4 2-12-4 In Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-12-4 is a locomotive with one pair of unpowered leading wheels, followed by six pairs of powered driving wheels, and two pairs of unpowered trailing wheels....
	4-12-2 4-12-2 A 4-12-2, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with four leading wheels, twelve driving wheels in a rigid frame, and two trailing wheels....	Union Pacific

	4-14-4 4-14-4 A 4-14-4, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a locomotive with four leading wheels, fourteen coupled driving wheels in a rigid frame, and four trailing wheels....	AA20

Duplex Duplex 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.... locomotives

	4-4-4-4 4-4-4-4 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....	(PRR T1 PRR T1 The Pennsylvania Railroad's 52 T1 class duplex locomotive 4-4-4-4 steam locomotives, introduced in 1942 and 1946 were their last-built steam locomotives, and their most controversial.... )
	6-4-4-6 6-4-4-6 A 6-4-4-6 steam locomotive, in the Whyte notation for describing locomotive wheel arrangements, is one with six leading wheels, two sets of four driving wheels, and six trailing wheels....	(PRR S1 PRR S1 The Pennsylvania Railroad S1 class steam locomotive was an experimental locomotive that was the largest rigid frame passenger locomotive ever built.... )
	4-4-6-4 4-4-6-4 A 4-4-6-4, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is one that has four leading wheels followed by four coupled driving wheels, a second set of six coupled driving wheels and four trailing wheels....	(PRR Q2 PRR Q2 The Pennsylvania Railroad's class Q2 comprised one prototype and twenty-five production duplex locomotive steam locomotives of 4-4-6-4 wheel arrangement.... )
	4-6-4-4 4-6-4-4 In Whyte notation, a 4-6-4-4 is a railroad steam locomotive that has four leading wheels followed by six coupled driving wheels, a second set of four driving wheels and four trailing wheels....	(PRR Q1 PRR Q1 The Pennsylvania Railroad's class Q1 comprised a single experimental steam locomotive for freight service, #6130, built in March 1942 in rail transport.... )

Mallet (simple and compound) articulated locomotives

	0-4-4-0 0-4-4-0 In the Whyte notation for the classification of steam locomotive wheel arrangement, a 0-4-4-0 is a locomotive with no leading truck, two sets of four driving wheels, and no trailing truck....	Bavarian BB II Bavarian BB II The Bavarian Class BB II engines were Mallet saturated steam locomotives in the service of the Royal Bavarian State Railways .They were specially designed for branch lines with tight curves and supplied in two series....
	2-4-4-2 2-4-4-2 In Whyte notation, 2-4-4-2 refers to a railroad steam locomotive that has two leading wheels followed by four coupled driving wheels, a second set of four coupled driving wheels, and two trailing wheels....
	0-6-6-0 0-6-6-0 In Whyte notation, a 0-6-6-0 is a railroad steam locomotive that has two articulated sections, each with six coupled driving wheels, without any leading wheels or trailing wheels....	Erie
	2-6-6-0 2-6-6-0 In Whyte notation for the classification of steam locomotives by wheel arrangement, a 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....	Denver & Salt Lake
	2-6-6-2 2-6-6-2 In Whyte notation, 2-6-6-2 refers to a railroad steam locomotive that has two leading wheels followed by six coupled driving wheels, a second set of six coupled driving wheels, and two trailing wheels....
	2-6-6-4 2-6-6-4 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....	Norfolk & Western
	2-6-6-6 2-6-6-6 The 2-6-6-6 is an articulated locomotive type with 2 leading wheels, two sets of six driving wheels and six trailing wheel Only two classes of the 2-6-6-6 type were built....	Allegheny, Blue Ridge
	4-6-6-2 4-6-6-2 In Whyte notation, a 4-6-6-2 is a steam locomotive with four leading wheels in an unpowered bogie at the front of the locomotive followed by two sets of driving wheels with six wheels each , followed by two unpowered trailing wheels at the rear of the locomotive....	(Southern Pacific class MM-2 Southern Pacific class MM-2 Southern Pacific Railroad's MM-2 class of steam locomotives was Southern Pacific's only class of 2-6-6-2 locomotives ordered and built as cab forward locomotives.... )
	4-6-6-4 4-6-6-4 In Whyte notation, a 4-6-6-4 is a railroad steam locomotive that has four leading wheels followed by six coupled driving wheels, a second set of six driving wheels and four trailing wheels....	Challenger

	2-6-8-0 2-6-8-0 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....	(Southern Railway, Great Northern Railway)

	0-8-8-0 0-8-8-0 In the Whyte notation for classifying the wheel arrangement of steam locomotives, an 0-8-8-0 is a locomotive with two sets of eight driving wheels and neither leading wheels nor trailing wheels....	Angus
	2-8-8-0 2-8-8-0 In the Whyte notation for the classification of steam locomotives by wheel arrangement, a 2-8-8-0 is a locomotive with a two-wheel leading truck, two sets of eight driving wheels, and no trailing truck....	Bull Moose
	2-8-8-2 2-8-8-2 .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....	Chesapeake
	2-8-8-4 2-8-8-4 Under the Whyte notation for the classification of steam locomotives, a 2-8-8-4 is a steam locomotive with two leading wheels, two sets of eight driving wheels, and a four-wheel trailing truck....	Yellowstone
	4-8-8-2 4-8-8-2 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....	Southern Pacific Southern Pacific Railroad The Southern Pacific Transportation Company , earlier Southern Pacific Railroad and Southern Pacific Company , was an United States railroad.... cab forward Cab forward The term cab forward refers to various Rail transport and road vehicle designs which place the driver's compartment substantially farther towards the front than is common practice.... classes AC-4 Southern Pacific class AC-4 Southern Pacific Railroad's AC-4 class of steam locomotives was the first class of cab forward locomotives built with the 4-8-8-2 wheel arrangement.... through AC-12 Southern Pacific class AC-12 Southern Pacific Railroad's AC-12 class of cab forward steam locomotives was the last class of steam locomotives ordered by Southern Pacific. They were built by Baldwin Locomotive Works during World War II, with the first, number 4275, entering service on October 27 1943, and the last, 4294, on March 19 1944.... (except AC-9 Southern Pacific class AC-9 The AC-9 was the Southern Pacific Railroad's only Articulated locomotive steam locomotive class that ran smokebox forward after 1920. Twelve AC-9 class locomotives were built by Lima Locomotive Works in 1939.... )
	4-8-8-4 4-8-8-4 In the Whyte notation for the classification of steam locomotives by wheel arrangement, a 4-8-8-4 is a locomotive with a four-wheel leading truck, two sets of eight driving wheels, and a four-wheel trailing truck....	Big Boy

	2-10-10-2 2-10-10-2 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....	(Santa Fe and Virginian railroads)

	2-8-8-8-2 2-8-8-8-2 Under the Whyte notation for the classification of steam locomotives, a 2-8-8-8-2 has two leading wheels, three sets of eight driving wheels, and two trailing wheels....	Triplex (Erie RR)
	2-8-8-8-4 2-8-8-8-4 Under the Whyte notation for the classification of steam locomotives, a 2-8-8-8-4 has two leading wheels, three sets of eight driving wheels, and a four trailing wheels....	Triplex (Virginian RR)

Garratt Garratt A Garratt is a type of steam locomotive that is articulated locomotive in three parts. Its boiler is mounted on the centre frame, and two steam engines are mounted on separate frames, one on each end of the boiler.... articulated locomotives

	0-4-0+0-4-0 0-4-0+0-4-0 A 0-4-0+0-4-0, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a Garratt articulated locomotive. It features no leading wheel or trailing wheels at either end, having only two sets of four driving wheels....
	2-6-2+2-6-2 2-6-2+2-6-2 A 2-6-2+2-6-2, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a Garratt articulated locomotive.Other equivalent classifications are:...

Whyte notation

Method

Articulated locomotives

Suffixes

Internal combustion locomotives

Limitations

Naming

Common wheel arrangements

See also