Whyte notation 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 ce ...

, 2-4-4-2 refers to a

railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

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 ...

that has two

leading wheel The leading wheel or leading axle or pilot wheel 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 on a leading truck. Leading wheels are used ...

s followed by four coupled

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, a second set of four coupled driving wheels, and two

trailing wheel On a steam locomotive, a trailing wheel or trailing axle is generally an unpowered wheel or axle ( wheelset) located behind the driving wheels. The axle of the trailing wheels is usually located in a trailing truck. On some large locomotives, ...

Equivalent classifications

Other equivalent classifications are: *

UIC classification The UIC classification of locomotive axle arrangements, sometimes known as the German classification''The Railway Data File''. Leicester: Silverdale, 2000. p. 52. . or German system,Kalla-Bishop P.M. & Greggio, Luciano, ''Steam Locomotives'', Cre ...

: 1BB1 (also known as German classification and

Italian classification The UIC classification of locomotive axle arrangements, sometimes known as the German classification''The Railway Data File''. Leicester: Silverdale, 2000. p. 52. . or German system,Kalla-Bishop P.M. & Greggio, Luciano, ''Steam Locomotives'', Cre ...

) *

French classification Under the French classification system for locomotive wheel arrangements, the system is slightly different for steam and electric/diesel vehicles. Steam The French system counts axles, rather than wheels. As with Whyte notation, a conventional r ...

: 120+021 *

Turkish classification In the Turkish classification system for railway locomotives, the number of powered axles are followed by the total number of axles. It is identical to the Swiss system except that the latter places a slash between the two numbers. Thus 0-6-0 beco ...

: 23+23 *

Swiss classification For more than a century, the Swiss locomotive, multiple unit, motor coach and railcar classification system, in either its original or updated forms, has been used to name and classify the rolling stock operated on the railways of Switzerland. ...

: 2/3+2/3 The

is refined to (1'B)B1' for a

Mallet locomotive The Mallet locomotive is a type of articulated steam railway locomotive, invented by the Swiss engineer Anatole Mallet (1837–1919). The front of the locomotive articulated on a bogie. The compound steam system fed steam at boiler pressure ...

US Examples

This articulated wheel arrangement was rare in North America; example was the

. Most were built as logging locomotives, presumably to better negotiate the uneven (and often temporary) trackwork that characterized such operations. The added mechanical complexity was found to be of limited value, as reflected in their modest production and use. Skookum_Rebuild_June_2015

There is one known surviving example: The Deep River Logging No. 7 "Skookum" (former Little River No. 126), built by Baldwin Locomotive Works in June 1909. It was retired and abandoned in place in the forest following a derailment wreck in 1955. As of September 2018, it is nearing completion of restoration to operating condition at the

Oregon Coast Scenic Railroad The Oregon Coast Scenic Railroad (OCSR) is a heritage railroad, a 501(c)(3) non-profit organization, operating in Oregon, primarily between Garibaldi and Rockaway Beach, with additional special trips to Wheeler, Nehalem River and into the Salm ...

shop in

Garibaldi, Oregon Garibaldi ( ) is a city in Tillamook County, in the U.S. state of Oregon. The population was 797 at the 2020 census. History The indigenous Tillamook people have lived along the Oregon coast –including the Tillamook Bay– for about 12,000 yea ...

New Zealand

ALCO Number 7

Built by

ALCO The American Locomotive Company (often shortened to ALCO, ALCo or Alco) was an American manufacturer of locomotives, diesel generators, steel, and tanks that operated from 1901 to 1969. The company was formed by the merger of seven smaller locomo ...

, this locomotive is a Mallet Compound engine, built for the Taupo Totara Timber Co for use on their 51-mile private tramway system, the

Mokai Tramway The Mokai Tramway was a bush tramway constructed by the Taupo Totara Timber Company (TTT Co) to link their milling centre at Mokai with the New Zealand Railways Department, New Zealand Government Railways line (NZR) at Putāruru in the Waikato ...

between

Putāruru Putāruru is a small town in the South Waikato District and the Waikato region of New Zealand's North Island. It lies on the western side of the Mamaku Ranges and in the upper basin of the Waihou River. It is on the Oraka Stream 65 kilometres s ...

and Mokai in the North Island. It is now preserved on the

Glenbrook Vintage Railway The Glenbrook Vintage Railway (GVR) is a heritage steam railway in Glenbrook, New Zealand. The GVR is run by a trust board of three trustees elected and appointed from Railway Enthusiasts Society (RES) membership. The board appoints a general m ...

, near Auckland, New Zealand and now carries the number 4. The engine is currently out of service awaiting overhaul, but can still be seen at the railway's Pukeoware workshops.

References

44,2-4-4-2 {{steam-loco-stub