4-8-6

Under the

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 cen ...

for the classification of

steam locomotives 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 ...

, a 4-8-6 locomotive would have had four

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, eight coupled driving wheels and six

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, ...

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'', Cre ...

: 2D3 (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 ...

: 243 *

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 ...

: 49 *

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. ...

: 4/9 This wheel arrangement was proposed by

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 shop's location in Lima, Ohio. The shops were located between ...

in 1949 as a continuation of their " Super Power" concept, essentially an expansion of the

4-8-4 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles, eight powered and coupled driving wheels on four axles and four trailing wheels on two axles. The type wa ...

. A larger

firebox Firebox may refer to: *Firebox (steam engine), the area where the fuel is burned in a steam engine *Firebox (architecture), the part of a fireplace where fuel is combusted *Firebox Records Firebox Records was a Finnish record label based in S ...

similar to the ones on the

2-6-6-6 The 2-6-6-6 (in Whyte notation) 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 L ...

locomotives built by Lima would have been fitted, allowing for greater power at speed. Despite promotion by Lima, there is no firm evidence that an example of this type was ever built and no nickname was ever assigned to the arrangement. In 1949, few railroads were interested in new steam locomotives due to steady improvements in diesel-electric locomotives. It is possible that CB&Q 4-8-4 5601 was experimentally equipped with a six-wheel trailing truck to allow use on branch lines with lighter rail, but the experiment was unsuccessful. Photographic evidence is said to have existed in the 1950s, but no photos are known to exist at present. Despite there being no documented full size examples built, there have been some 4-8-6s built for

model railroad Railway modelling (UK, Australia, New Zealand, and Ireland) or model railroading (US and Canada) is a hobby in which rail transport systems are modelled at a reduced scale. The scale models include locomotives, rolling stock, streetcars, t ...

s. Reference: *Bill Withuhn, "Did we scrap steam too soon?", in ''Trains'', Vol. 34, No. 8, June 1974, pp. 36–47. 8,4-8-6 {{steam-loco-stub