ATSF FM H12-44 513 at Chicago, Illinois, May, 1973. Photographer: David P Wagner.

(Craig Garver, Public domain,



The FM H-12-44 was a switcher locomotive produced by Fairbanks-Morse from May 1950 until March 1961. The units had a 1,200-horsepower (890 kW), six-cylinder opposed piston engine prime mover, and were configured in a B-B wheel arrangement mounted atop a pair of two-axle AAR Type-A switcher trucks, with all axles powered and geared for a top speed of 60 miles per hour (97 km/h).

Of the 336 H-12-44 locomotives produced, 303 were for American railroads, 30 were made between August 1951 to June 1956 by the Canadian Locomotive Company for use in Canada, and one was exported to Mexico.

H-12-44s were visually indistinguishable from the predecessor FM H-10-44 until September 1952, when the Raymond Loewy design elements were removed to reduce production costs. Cab lines were squared-off, the slanted-nose styling was discontinued, and the roof visor was eliminated. The following year, the fairing over the battery box was removed and louvers added to reduce the chance of battery explosions. Production paused from May to October 1956, after which the carbodies were shortened by some three feet and outfitted with a deeper side skirt.

Sixteen intact examples of the H-12-44 are known to survive, all of which are owned by railroad museums or historical societies.

One, FM H-12-44TS, Santa Fe 543, now resides at the Illinois Railway Museum.


Chihuahua al Pacfico FM H12-44 301 at Chihuahua, Chihuahua, Mexico, September 5, 1973. Photographer: Peter Arnold.

(Craig Garver, Public domain, Flickr)


Units produced by Fairbanks-Morse (1950–1961)

Railroad Quantity Road numbers Notes
Fairbanks-Morse (demonstrator) 1 76 to Yankeetown Dock Corporation 1
Atchison, Topeka and Santa Fe Railway 59 503–540, 544–564 3 custom-built H12-44TS locomotives 541-543. 543 survives today
Ayrshire Collieries Corporation 1 1 to Thunderbird Collieries 1; to Yankeetown Dock 3
Baltimore and Ohio Railroad 17 196–197, 310–319, 9722–9726 310–319 renumbered 9710–9719, 196–197 renumbered 9720–9721
Canadian National Railway 30 1630–1659 built by Canadian Locomotive Company
Central of Georgia Railway 4 315–318
Chicago and North Western Railway 9 1071–1072, 1110–1116
Chicago, Milwaukee, St. Paul and Pacific Railroad ("Milwaukee Road") 48 1826–1847, 2309–2325 Renumbered 700–710, 715–744, 750–756 (not in order)
Columbia and Cowlitz Railway 1 D-2 Renumbered #700
Ferrocarril de Chihuahua al Pacífico 1 70
Indianapolis Union Railway 3 19–21
Kentucky and Indiana Terminal Railroad 7 60–66
Minneapolis, St. Paul and Sault Ste. Marie Railroad ("Soo Line") 5 315–319
Minnesota Western Railway 1 10 to Minneapolis, Northfield and Southern Railway 10
New York Central Railroad 27 9111–9137 To Penn Central 8300-8326
New York, Chicago and St. Louis Railroad ("Nickel Plate Road") 22 134–155 to Norfolk and Western Railway 2134–2155
Pennsylvania Railroad 16 8708–8723 to Penn Central 8327–8342
Sandersville Railroad 1 100 Renumbered 10
St. Louis-San Francisco Railway ("Frisco") 4 282–285
Southern Pacific Company 43 1486–1491, 1529–1574, 1577–1596
Southern Pacific (Texas and New Orleans Railroad) 2 119–120 to Southern Pacific 1575–1576; renumbered 2373–2374
Tennessee Valley Authority 1 22
United States Army 20 1843–1862
U.S. Steel, Morrisville, Pennsylvania 8 GE9–GE16
Wabash Railroad 3 384–386 to Norfolk and Western 3384–3386
White River Lumber Company (Weyerhaeuser Timber Company)   1 WTC 1 to Pacific Transportation Services 121 then transferred to Northwest Railway Museum where it is preserved in running condition
Yankeetown Dock Corporation 1 2
Total 336

An F-M H-12-44 Gallery


Chihuahua al Pacifico FM H12-44 301 at Chihuahua, Chihuahua, Mexico, December, 1974. Photographer: Paul Hunnell. (Craig Garver, Public domain, Flickr)

AT&SF FM H-12-44TS 543 at Chicago, Illinois, date unknown. Photographer: Stan Kistler. (Craig Garver, Public domain, Flickr)


ATSF FM H-12-44TS 542 at Beloit, Wisconsin, in May, 1956, in a builder photo. (Craig Garver, Public domain, Flickr)

US Steel Fairless Works FM H-12-44 GE11 at Beloit, Wisconsin, July, 1952, in a Fairbanks Morse builder photo. (Craig Garver, Public domain, Flickr)

Milwaukee Road FM H-12-44 2308 at Marion, Iowa, February 28, 1965. Photographer: Unknown. (Craig Garver, Public domain, Flickr)

Southern Pacific FM H-12-44 1488 at Tucson, Arizona. Date and photographer unknown. (Craig Garver, Public domain, Flickr)

Milwaukee Road Fairbanks Morse H12-44 1831, Milwaukee, Wisconsin, March 24, 1951. Photographer: unknown. (Craig Garver, Public domain, Flickr)

Southern Pacific FM H-12-44 2355, date, location and photographer unknown. (Craig Garver, Public domain, Flickr)

Southern Pacific FM H-12-44 2377 at San Francisco, California, June 16, 1963. Photographer: Neil Shankweiler. (Craig Garver, Public domain, Flickr)

Southern Pacific FM H-12-44 2357 at El Paso, Texas, December 1, 1974. Photographer: Bruce Black. (Craig Garver, Public domain, Flickr)

ATSF FM H12-44 557, date, location and photographer unknown. (Craig Garver, Public domain, Flickr)

ATSF FM H1244 510 at Chicago, Illinois, June 5, 1970. Photographer: Lee Hastman. (Craig Garver, Public domain, Flickr)

SP 2380 switching the Del Monte at San Jose, April 1971. (Drew Jacksich from San Jose, California Republic, CC BY 2.0 <>, via Wikimedia Commons)

Weyerhaeuser Timber Company FM H 12-44 No 1. (Bradley24hi, CC BY-SA 4.0 <>, via Wikimedia Commons)

Ex-US Army 1847, repainted in "Tiger Stripe" yard switcher livery as SP 1487. Collection of Golden Gate Railroad Museum. (GGRM) (Nate Beal, CC BY 2.0 <>, via Wikimedia Commons)


Several examples of the H-12-44 model have been preserved around the U.S. and Canada.

  • Weyerhaeuser Timber Company No. 1 is preserved at the Northwest Railway Museum in Snoqualmie, Washington. After undergoing a full rebuild and engine overhaul, the locomotive is now run only for special events with its partner caboose, White River Logging Company number 001.
  • Former US Army No. 1843 is a part of the collection at the Rochester & Genesee Valley Railroad Museum in Rush, New York (south of Rochester). It is in operable condition and is a key locomotive at the RGVRRM.
  • Former US Army later US Steel No. 1845 is currently stored at Fairless Hills, Pennsylvania, undergoing restoration. It is privately owned.
  • Former US Army No. 1847 is preserved at the Golden Gate Railroad Museum in Sunol, California. It is currently operational and has been painted in "Tiger Stripe" scheme to represent Southern Pacific No. 1487.
  • Former US Army No. 1849 is preserved for static display at the Bluegrass Railroad Museum in Versailles, Kentucky.
  • Former US Army No. 1850, No. 1853 and No. 1861 are stored out of service at the Heart of Dixie Railroad Museum in Calera, Alabama.
  • Former US Army No. 1855 owned and operated (on excursion trains) by Nevada State RR Museum, Boulder City, Nevada.
  • Former US Army No. 1854 switches Business Depot Ogden in Utah as of 2019. It wears Utah Central 1854 and Defense Logistics Agency 53205.
  • Former US Army No. 1857 is preserved at the Western Pacific Railroad Museum at Portola, California. It was used at the Sierra Army Depot at Herlong, California, located along the former Western Pacific Railroad. It is used in the museum's famous "Rent-A-Locomotive" program.
  • Former US Army unit No. 1860, worked at Sunny Point Military Ocean Terminal. It later went to Beaufort & Morehead Railroad in North Carolina as No. 1860, based at the Morehead City State Ports. The North Carolina Transportation Museum acquired the locomotive in 2004 after disposition from the State Ports.
  • Former US Steel No. 9121 is preserved by the United Railroad Historical Society of New Jersey. Restoration is underway at SMS Railroad in Bridgeport, New Jersey.
  • Atchison, Topeka and Santa Fe No. 608 (formerly No. 508) is at the Museum of the American Railroad in Frisco, TX, following a 2017 transfer from the California State Railroad Museum in Sacramento, California.
  • Atchison, Topeka and Santa Fe No. 560 is preserved at the Southern California Railway Museum in Perris, California.
  • Milwaukee Road No. 740 is preserved at the Mad River and NKP Railroad Museum in Bellevue, Ohio. It was originally numbered 2310.



Type and origin
Power type: Diesel-electric
Builder: Fairbanks-Morse
Model: H-12-44
Build date: May 1950 – March 1961
Total produced: 336
​• AAR B-B
Gauge: 4 ft 8+1⁄2 in (1,435 mm)
Trucks: AAR type A
Wheel diameter: 40 in (1,016 mm)
Minimum curve: 29.50 (194 ft (59.13 m) radius)
Wheelbase: 33 ft 6 in (10.21 m)
Length: 48 ft 10 in (14.88 m)
Width: 10 ft 4 in (3.15 m)
Height: 14 ft 6+5⁄8 in (4.44 m)
Locomotive weight: 240,000 lb (108.9 t)
Prime mover: FM 38D-8 1/8
Engine type: Opposed piston Two-stroke diesel
Aspiration: Roots blower
Displacement: 6,222 cu in (101.96 L)
Generator: FM DGZJ
Traction motors: (4) FM DRZH
Cylinders: 6 (Opposed piston)
Cylinder size: 8.125 in × 10 in (206 mm × 254 mm)
Locomotive brake: Straight air
Train brakes: Air
Performance figures
Maximum speed: 60 mph (97 km/h)
Power output: 1,200 hp (895 kW)
Tractive effort: 40,440 lbf (179.9 kN))
Locale: North America
Disposition: Most scrapped, sixteen examples preserved