2-10-4 "Texas" Steam Locomotive
Under the Whyte notation for the classification of steam locomotives, a 2-10-4 locomotive has two leading wheels on one axle, ten coupled driving wheels on five axles, and four trailing wheels on two axles, usually in a truck. These were referred to as the Texas type in most of the United States, the Colorado type on the Burlington Route and the Selkirk type in Canada.

The 2-10-4 Texas wheel arrangement originated and was principally used in the United States of America. The evolution of this locomotive type began as a 2-10-2 Santa Fe type with a larger four-wheeled trailing truck that would allow an enlarged firebox. A subsequent development was as an elongated 2-8-4 Berkshire type that required extra driving wheels to remain within axle load limits. Examples of both of these evolutionary progressions can be found.

Some 2-10-4 tank locomotives also existed in eastern Europe. One extraordinary experimental 2-10-4 tender locomotive, built in the Soviet Union, had an opposed piston drive system.

United States
Atchison, Topeka & Santa Fe
The Atchison, Topeka & Santa Fe Railway (ATSF) took delivery of locomotive No. 3829 from the Baldwin Locomotive Works in 1919. It was used by Santa Fe as an experimental locomotive and was rostered as a member of ATSF’s 3800 class of 2-10-2s that was fitted with a four-wheel trailing truck. Nearly a hundred more 3800 class locomotives were delivered after no. 3829, but all with the 2-10-2 wheel arrangement. Photographs exist that show no. 3829 fitted with at least two different designs of four-wheel trailing truck through the years. No other members of the 3800 class have been documented with four-wheel trailing trucks. No. 3829 was scrapped in 1955, still equipped with a four-wheel trailing truck.

ATSF 2-10-4 No. 5000 Madame Queen
Santa Fe, who had originated the 2-10-4 type, adopted it again in 1930 with no. 5000, nicknamed Madame Queen. This locomotive was similar to the C&O T-1, with the same 69 inches (1,753 millimeters) drivers but with 300 pounds per square inch (2,100 kilopascals) boiler pressure and 60% limited cutoff. It proved the viability of the type on the Santa Fe railway, but the Great Depression shelved plans to acquire more.

In 1938, with the railroad's fortunes improving, Santa Fe acquired ten more 2-10-4 locomotives. These came with 74 inches (1,880 millimeters) diameter drivers and 310 pounds per square inch (2,100 kilopascals) boiler pressure, making these ATSF 2-10-4s the fastest and most modern of all.

Of the original order of ten, five were oil-burning and five coal-burning, but when Santa Fe ordered twenty-five more for delivery in 1944, all were delivered equipped to burn oil. The first of the 1944 batch produced 5,600 drawbar horsepower on road test, the highest figure known for a two-cylinder steam locomotive.

Texas and Pacific
The 2-10-4 type was revived in 1925 by the Lima Locomotive Works. This time it was an expansion of the 2-8-4 Berkshire type that Lima had pioneered. A version of the Berkshire with ten driving wheels instead of eight was an obvious development and the first to be delivered were to the Texas and Pacific Railway, after which the type was subsequently named. The four-wheel trailing truck allowed a much larger firebox and thus a greater ability to generate heat, and thus steam. The Superpower design, as Lima's marketing department called it, resulted in a locomotive that could develop great power at speed while not running out of steam-generating ability.

Chesapeake & Ohio
The early Lima-built Texas types were low-drivered, 60 to 64 inches (1,524 to 1,626 millimeters) in diameter, which did not leave enough space to fully counterweight the extremely heavy and sturdy side rods and main rods required for such a powerful locomotive's piston thrusts. That changed in 1930 on the Chesapeake and Ohio Railway (C&O), who stretched the design of an Erie Railroad high-drivered Berkshire type locomotive to produce forty of the C&O T-1, a Texas type with 69 inches (1,753 millimeter) diameter drivers that was both powerful and fast enough for the new higher-speed freight services that the railroads were introducing. All subsequent Texas types were of this higher-drivered sort.

Pennsylvania
The Pennsylvania Railroad (PRR) ordered few new locomotives after 1930, since electrification both consumed the railroad's resources and resulted in a supply of excess steam locomotives that eliminated any requirement for new power. It was not until the Second World War had begun, that the PRR's locomotive fleet began to appear inadequate. Although the PRR urgently needed new and modern freight power, the War Production Board prohibited working on a new design and, since there was not enough time to trial a prototype in any event, the PRR cast around for other railroads' designs that it might modify for PRR use.

It settled on the C&O’s T-1. Some modifications were made to the design for these PRR War Babies. These included PRR drop-couplers, sheet steel pilots, PRR-style cabs, large PRR tenders, Keystone number plates up front and other modifications. It still betrayed its foreign heritage by lacking the PRR trademark Belpaire firebox and by having a booster engine on the trailing truck. Altogether 125 locomotives were built between 1942 and 1944 and became the largest fleet of Texas type locomotives in existence. All were eventually sold as scrap when the Pennsylvania Railroad dieselized.

Canada
The Canadian Pacific (CP) Selkirk locomotives were all built by Montreal Locomotive Works (MLW). The first twenty of these large engines were built in 1929, designated T1a class and allocated numbers 5900 to 5919. Their Canadian type name was after the Selkirk Mountains across which they were placed in service, the railway summit of which was located just inside the western portal of the Connaught Tunnel beneath Rogers Pass.

MLW built another ten of these successful locomotives for CP during November and December 1938, designated T1b class and numbered from 5920 to 5929. Modifications to the original design led to the T1b being ten tons lighter while its operating steam pressure was increased from 275 to 285 pounds per square inch (1,900 to 1,970 kilopascals).

A further six Selkirks, classed T1c and numbered from 5930 to 5935, were delivered by MLW in 1949. They were the last standard gauge steam locomotives to be built in Canada for a Canadian railway. These were very similar to the T1b class, apart from a few refinements which included two cross-compound air compressors to speed up recharging of the air brake system, while some small streamlining touches were not retained, such as the streamlined casing around the smokebox stack as well as the teardrop shape of the classification lights. In addition, the inside of the cabs were no longer insulated in the same manner as the previous versions, which had provided better cold-weather cab insulation and were better-liked by crews. The last Selkirks were taken out of service in 1959.

North American owners of Texas type 2-10-4 Construction Roster

Atchison, Topeka and Santa Fe
Quantity: 37

Nickname: Texas

Class: 3800

Road numbers: 3829

Builder: Baldwin

Year built: 1919

Class: 5000
Road numbers: 5000

Builder: Baldwin

Year built: 1930

Notes: preserved

Class: 5001
Road numbers: 5001–5010

Builder: Baldwin

Year built: 1938

Class: 5011
Road numbers: 5011–5035

Builder: Baldwin

Year built: 1944

Notes: 5011, 5017, 5021 & 5030 preserved.

Bessemer & Lake Erie
Quantity: 47

Nickname: Texas
Notes: 18 of the B&LE's 2-10-4 locomotives were sold to the Duluth, Missabe & Iron Range (DMIR), who retained the "Texas" class name on these locomotives.

Class: H1A

Road numbers: 601

Builder: Baldwin

Year built: 1929
Class: H1

Road numbers: 602–610

Builder: Baldwin

Year built: 1930
Class: H1

Road numbers: 611–620

Builder: Baldwin

Year built: 1936
Class: H1

Road numbers: 621–630

Builder: ALCO

Year built: 1937
Class: H1

Road numbers: 631–635

Builder: Baldwin

Year built: 1941
Class: H1

Road numbers: 636–637

Builder: Baldwin

Year built: 1942
Class: H1

Road numbers: 638–642

Builder: Baldwin

Year built: 1943
Class: H1G

Road numbers: 643–647

Builder: Baldwin

Year built: 1944

Notes: 643 preserved

Canadian Pacific
Quantity: 37

Nickname: Selkirk

Class: T1a

Road numbers: 5900–5919

Builder: MLW

Year built: 1929
Class: T4a

Road numbers: 8000

Builder: CP Angus Shops

Year built: 1931
Class: T1b

Road numbers: 5920–5929

Builder: MLW

Year built: 1938

Notes: Streamlined
Class: T1c

Road numbers: 5930–5935

Builder: MLW

Year built: 1949

Notes: Streamlined. 5931 & 5935 preserved

Central Vermont
Quantity: 10

Nickname: Texas

Class: T-3-a

Road numbers: 700–709

Builder: ALCO

Year built: 1928

Chesapeake and Ohio
Quantity: 40

Nickname: Texas

Class: T-1

Road numbers: 3000–3039

Builder: Lima

Year built: 1930

Chicago, Burlington & Quincy
Quantity: 18

Nickname: Colorado

Class: M-4

Road numbers: 6310–6321

Builder: Baldwin

Year built: 1927
Road numbers: 6322–6327

Builder: Baldwin

Year built: 1929

Chicago Great Western

Quantity: 36

Nickname: Texas

Class: T-1

Road numbers: 850–864, 880–882

Builder: Lima

Year built: 1930
Class: T-2

Road numbers: 865–873

Builder: Baldwin

Year built: 1930
Class: T-3

Road numbers: 874–879

Builder: Baldwin

Year built: 1930
Class: T-3

Road numbers: 883–885

Builder: Lima

Year built: 1931

Kansas City Southern
Quantity: 10

Nickname: Texas

Road numbers: 900–909

Builder: Lima

Year built: 1937

Pennsylvania Railroad
Quantity: 125

Nickname: Texas

Class: J1

Road numbers: 6450–6474

Builder: PRR Altoona Works

Year built: 1942
Road numbers: 6401–6434, 6475–6500

Builder: PRR Altoona Works

Year built: 1943
Road numbers: 6435–6449, 6150–6174

Builder: PRR Altoona Shops

Year built: 1944

Texas & Pacific
Quantity: 70

Nickname: Texas

Class: I-1

Road numbers: 600–609

Builder: Lima

Year built: 1925
Class: I-1a

Road numbers: 610–624

Builder: Lima

Year built: 1927

610 preserved
Class: I-1b

Road numbers: 625–639

Builder: Lima

Year built: 1928
Class: I-1c

Road numbers: 640–654

Builder: Lima

Year built: 1928
Class: I-1d

Road numbers: 655–669

Builder: Lima

Year built: 1929

Preserved Texas types in North America

AT&SF No. 5000 - Amarillo, TX
AT&SF No. 5011 - Museum of Transportation, St. Louis, MO
AT&SF No. 5017 - National Railroad Museum, Green Bay, WI
AT&SF No. 5021 - California State Railroad Museum, Sacramento, CA
AT&SF No. 5030 - Salvador Perez Park, Santa Fe, NM
B&LE No. 643 - McKees Rocks, PA
T&P No. 610 - Texas State Railroad, Palestine, TX

CP No. 5931 - Heritage Park Historical Village, Calgary, AB, Canada
CP No. 5935 - Canadian Railway Museum, Delson, QC, Canada

2-10-4 Texas Overview

Equivalent classifications
UIC class: 1E2
French class: 152
Turkish class: 58
Swiss class: 5/8
Russian class: 1-5-2
First known tender engine version
First use: 1919
Country: United States
Locomotive Number: 3829
Railroad: Atchison, Topeka and Santa Fe Railway
Designer: Baldwin Locomotive Works
Builder: Baldwin Locomotive Works
Evolved from: 2-10-2
Evolved to: 2-8-4

See also:

Steam Locomotives

A 2-10-4 Slideshow.

Santa Fe's "Big Maude" No. 5000. Library of Congress.

​Classic Streamliners - TRAIN​CYCLOPEDIA

Diagram of the 2-10-4 Wheel Arrangement: one small leading wheel, five large driving wheels joined together with a coupling rod, and two small trailing wheels. Front of locomotive at left.