In the

Whyte notation The 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 twenti ...

for describing

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, Fuel oil, oil or, rarely, Wood fuel, wood) to heat ...

wheel arrangement In rail transport, a wheel arrangement or wheel configuration is a system of classifying the way in which wheels are distributed under a locomotive. Several notations exist to describe the wheel assemblies of a locomotive by type, position, and c ...

, a 2-8-6 is a locomotive with a two-wheel leading truck, eight

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 t ...

s, and a six-wheel

trailing truck On a steam locomotive, a trailing wheel or trailing axle is generally an unpowered wheel or axle (Wheelset (rail transport), wheelset) located behind the driving wheels. The axle of the trailing wheels is usually located in a trailing Bogie, t ...

. All 2-8-6 locomotives constructed have been

Mason Bogie Mason Bogie locomotives (also known as Mason Fairlie locomotives) are a type of articulated tank locomotive suited for sharp curves and uneven track, once commonly used on narrow-gauge railways in the United States. The design is a development of ...

tank locomotive A tank locomotive is a steam locomotive which carries its water in one or more on-board water tanks, instead of a more traditional tender (rail), tender. Most tank engines also have Fuel bunker, bunkers (or fuel tanks) to hold fuel; in a #Tender ...

s. 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'', Cr ...

: 1D3 (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'', Cr ...

)

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 ...

: 143

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 bec ...

: 48

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. ...

: 4/8 In the

as applied in Germany and Italy, a rigid-framed locomotive of this arrangement would be 1'D3', and the Mason bogie (1'D)'3'. Four Mason Bogies of this type were built for the

Denver, South Park and Pacific Railroad The Denver, South Park, and Pacific Railroad (later called the Denver, Leadville and Gunnison Railway) was a historic narrow gauge railroad that operated in Colorado in the western United States in the late 19th century. The railroad opened up ...

; #25 ''Alpine'', #26 ''Rico'', #27 ''Roaring Fork'' and #28 ''Denver''. They were

narrow gauge A narrow-gauge railway (narrow-gauge railroad in the US) is a railway with a track gauge (distance between the rails) narrower than . Most narrow-gauge railways are between and . Since narrow-gauge railways are usually built with Minimum railw ...

locomotives of gauge. Two more went to the Denver, Utah and Pacific, #10 ''Middle Park'' and #19 ''Denver''. The DU&P sold one of the latter to the

Burlington and Northwestern Railway The Burlington and Northwestern Railway (B&NW) was a narrow gauge railroad system in Iowa that operated during the late nineteenth and early twentieth centuries. It connected Burlington, Iowa with branches to Washington and Oskaloosa, Iowa. In ...

, a narrow-gauge affiliate of the

CB&Q The Chicago, Burlington and Quincy Railroad was a railroad that operated in the Midwestern United States. Commonly referred to as the Burlington Route, the Burlington, CB&Q, or as the Q, it operated extensive trackage in the states of Colorado ...

operating in

Iowa Iowa ( ) is a U.S. state, state in the upper Midwestern United States, Midwestern region of the United States. It borders the Mississippi River to the east and the Missouri River and Big Sioux River to the west; Wisconsin to the northeast, Ill ...

.Mason Bogie loco 2-8-6T narrow gauge B&NW #1 (c1890)
BRHS Subject-Photo index, page M
, Burlington Route Historical Society, May 28, 2013.

References

8,2-8-6 {{steam-loco-stub