American Steam Locomotive Wheel Arrangements

All the locomotives listed here actually operated at one time or another on a North American railroad. This includes common carriers, elevated railways, cog railways and logging roads.

F. M. Whyte's system of classification is used to describe the wheel arrangement of conventional steam locomotives. In this system, the first number is the number of leading wheels, and the last is the number of trailing wheels. The middle number (or numbers) give the number and arrangement of drivers. A "T" at the end indicates a tank engine.

The system normally used to describe diesel-electric locomotives has also been used here for steam turbine electric locomotives. In this system, non-powered axles are given as numbers and powered axles are given as letters. There is no standard system of classification for geared locomotives such as Shays, Heislers and Climaxes. Instead, a brief description is given for each.

F.M.Whyte'sNameNotes, First examples
0-2-2-0The locomotives of the Mt. Washington Cog Railroad are examples of this type.
0-4-4TForney four-coupled
0-4-6TForney four-coupled
0-6-2TSeveral examples were built by Baldwin (25896, 25953) for the Uintah Railroad.
0-6-4TForney six-coupled
0-6-6TForney six-coupled
0-6-6-01904, Baltimore & Ohio. It was this first Mallet articulated built in the U.S.
0-8-2Many examples of this type were 2-8-2's that had been modified for yard work.
0-8-8-0Angus1907: Erie; 1910: D&H; 1922: B&M, B&O, N&W, NYC
0-10-2UnionFive examples built in 1936 for the Union Railroad of Pittsburgh.
0-12-0TOne example built in 1863 for the Philadelphia & Reading
2-4-2ColumbiaFirst shown at the 1893 Columbian exposition in Chicago
2-6-0MogulFirst rigid frame: 1852; First swiveling: 1864 (L&N)
2-6-2Prairie1900: Chicago, Burlington and Quincy.
2-6-4Adriaticnone in North America
2-6-4TUsed in suburban service
2-6-6-01909: Virginian
2-6-6-2TSeveral examples built by Baldwin for the Uintah RR in 1926-28 were the largest narrow guage locomotives ever built.
2-6-6-21906: Great Northern; Last: 1949: C&O
2-6-6-41934: Pittsburg & West Virginia; Most powerful: Norfolk & Western 1936-50
2-6-6-6Allegheny1941: Chesapeake & Ohio
Blue Ridge1945: Virginian
2-6-8-0The Southern and the Great Northern had the sole examples of this type.
2-8-0Consolidation1866: Lehigh Valley (which had recently been created by the merger of several smaller roads). Most popular wheel arrangement in U.S.
2-8-2Mikado1897: built by Baldwin for export to Japan
MacArthurWorld War II era
2-8-4Berkshire1925: class A-1 demonstrater by Lima Locomotive works. Early tests were on the Boston & Albany.
KanawhaChesapeake & Ohio
LimaBoston & Maine, Illinois Central
2-8-8-2Cab Forward1909: Southern Pacific (#4000), 1910: (#4002)
Chesapeake1924: Chesapeake & Ohio
2-8-8-4Yellowstone1928: Northern Pacific
2-8-8-8-2Triplex1913: Erie (3 total), rear drivers under the tender
2-8-8-8-4Triplex1919: Virginian (1 example), rear drivers under tender
2-10-0Decapod1867: Lehigh Valley
2-10-2Santa Fe1903: Atchison, Topeka & Santa Fe
CentralIllinois Central
DecapodSouthern Pacific
2-10-4Texas1925: Texas & Pacific
ColoradoChicago, Burlington & Quincy
SelkirkCanadian Pacific
2-10-10-21911: Santa Fe (rebuilt from 2-10-2s); 1918: Virginian
4-2-0Six wheeler
Jervis1832: invented by John B. Jervis of the Mohawk & Hudson
4-2-4Tinspection locomotives
Eight wheeler
4-4-2Atlantic1887, 1888: two examples built; 1895: Atlantic Coast Line
ChautauquaBrooks Locomotive Works
MilwaukeeMilwaukee Hiawatha
4-4-4Reading1915: Reading
JubileeCanadian Pacific
Lady BaltimoreBaltimore & Ohio
4-4-4-4Baltimore&Ohio1937: Baltimore & Ohio #5600
Duplex1942-45: 52 examples by the Pennsylvania Railroad
4-4-6Four-coupled, double-ender
4-4-6-21909: Santa Fe (two examples)
4-4-6-4Duplex-Drive1944: 26 examples built by the Pennsylvania Railroad
4-6-0Ten wheeler
4-6-2Pacific1901: built by Baldwin for New Zealand railways; 1902: Missouri, Pacific & St. Louis, Iron Mountain & Southern 1902
4-6-4TCanadian National Railways
4-6-4Hudson1927: New York Central
MilwaukeeMilwaukee Road
BalticMilwaukee Road
Shore LineNew Haven
4-6-4-4Duplex-Drive1942: Pennsylvania Railroad (one example)
4-6-6-2Cab Forward1911: Southern Pacific
4-6-6-4Challenger1936: Union Pacific
4-8-0Twelve wheeler
Mastodon1882: Central Pacific (one example named Mastodon)
4-8-2Mountain1911: Chesapeake & Ohio
MohawkNew York Central
New HavenNew Haven 3 cylinder
4-8-41921: Sante Fe
Northern1927: Northern Pacific
ConfederationCanadian National
DixieNashville, Chattanooga & St. Louis (and other Southern Roads)
Golden StateSouthern Pacific
GreenbriarChesapeake & Ohio
Montanawhat railroad?
NiagaraNew York Central
NiagraNacionales de Mexico
PotomacWestern Maryland
WyomingLehigh Valley
Generals, GovernersRichmond, Fredericksburg & Potomac
4-8-8-2Cab Forward1928: Southern Pacific
4-8-8-4Big Boy1941: Union Pacific (25 examples)
4-10-0Mastodon1883: Central Pacific (only one example, named El Gobernador)
4-10-2SouthernPacific1925: Southern Pacific (#5000)
Overland1925: UP (#8800)
4-12-2Union Pacific1926: UP (88 examples)
6-2-0Crampton1849: Camden & Amboy (three examples)
6-4-4-6Pennsylvania1939: Pennsylvania (one example: #6100)
6-8-61944: Pennsylvania (#6200 steam turbine, direct drive)
2+C+C+21938: UP (steam turbine electric, flash boiler)
2-C1+2-C1+B1947: C&O (three examples, steam turbine electric)
C+C+C+CJawn Henry1955: N&W (steam turbine electric)
2-truckShayGeared. 4-wheel trucks.
3-truckShayGeared. 4-wheel trucks.
4-truckShayGeared. 4-wheel trucks.
3-truckWillametteGeared. 4-wheel trucks.
2-truckHeislerGeared. 4-wheel trucks.
3-truckHeislerGeared. 4-wheel trucks.
2-truckClimaxGeared. 4-wheel trucks.
3-truckClimaxGeared. 4-wheel trucks.

Abdill, George B.A Locomotive Engineer's Album.New York: Bonanza Books, 1965.
Alexander, Edwin P.Iron Horses: American Steam Locomotives, 1829-1900.New York: Bonanza Books, 1941.
Alexander, Edwin P.The Pennsylvania Railroad: A Pictorial History.New York: Bonanza Books, 1947.
Alexander, Edwin P.American Steam Locomotives: A Pictorial Record of Steam Power, 1900-1950.New York: Bonanza Books, 1950.
Comstock, Henry B.The Iron Horse.Galahad Press, 1971.
Holbrook, Stewart H.The Story of American Railroads.New York: Crown Publishers, 1947.
Keefe, Kevin P.ABC's of Railroading.Trains Magazine, May 1991.
MacBride, H. A.Trains Rolling.New York: MacMillan, 1953.
Morgan, David P.Steam's Finest Hour.Milwaukee: Kalmbach Books, 1959.
Morgan, David P.The Mohawk that Refused to Abdicate.Milwaukee: Kalmbach Books, 1975.
Locomotive & Railway Preservation Magazine
Railroad Magazine
Trains Magazine
George DruryGuide to North American Steam Locomotives1993, Kalmbach

This list was originally compiled by Richard Boylan ( Since it's posting on May 30, 1991, on rec.railroad, Wes Barris has made many additions.

Schenzinger Image Directory | The Steam Era | Home Page