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 locomotive

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 ...

s, a 4-4-6-2 is a locomotive with two pairs of

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, one set of four driving wheels, a second set of six driving wheels, and a pair of

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 ...

: 2BC1 (also known as German classification and

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. ...

)
Italian and French classification: 220+031
The equivalent

is refined to (2′B)C1′ for Mallet locomotives. This wheel arrangement was rare. Only two are known to have been built, both as compound Mallet locomotives by Baldwin Locomotive Works in 1909 for the

Atchison, Topeka and Santa Fe Railway The Atchison, Topeka and Santa Fe Railway , often referred to as the Santa Fe or AT&SF, was one of the larger railroads in the United States. The railroad was chartered in February 1859 to serve the cities of Atchison, Kansas, Atchison and Top ...

. They were initially numbered 1300 and 1301 but soon re-numbered 1398 and 1399. "The Jointed-Boiler Locomotives," ''

Trains In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives (often know ...

'' magazine, February 1945 These locomotives were perhaps the first and only attempt to adapt the Mallet-compound design for passenger service, having been built with 73-inch driving wheels. The experiment was unsuccessful: Adhesion stability was a problem, as the front engine tended to slip uncontrollably because of an imbalance of tractive effort at passenger-train speeds (this was a common problem with compound Mallets, at any speed much above walking pace). Both locomotives were rebuilt to non-compound

4-6-2 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles, six powered and coupled driving wheels on three axles and two trailing wheels on one axle. The locomo ...

types in 1915, retained their assigned numbers, and were still in use on the AT&SF as of 1944. They were retired by 1950.

References

{{commons category Atchison, Topeka and Santa Fe Railway locomotives Steam locomotives of the United States Railway locomotives introduced in 1915