FM H-12-44

Last updated
FM H-12-44
Del Monte in San Jose, April 1971.jpg
SP #2380 backs the Del Monte into San Jose in April 1971, a week before the Amtrak takeover.
Type and origin
Power typeDiesel-electric
Builder Fairbanks-Morse
Build dateMay 1950 – March 1961
Total produced336
   AAR B-B
Gauge 4 ft 8 12 in (1,435 mm)
Trucks AAR type A
Wheel diameter40 in (1,016 mm)
Minimum curve 29.50 (194 ft (59.13 m) radius)
Wheelbase 33 ft 6 in (10.21 m)
Length48 ft 10 in (14.88 m)
Width10 ft 4 in (3.15 m)
Height14 ft 6 58 in (4.44 m)
Loco weight240,000 lb (108.9 t)
Prime mover FM 38D-8 1/8
Engine type Opposed piston Two-stroke diesel
Aspiration Roots blower
Displacement6,222 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)
Loco brake Straight air
Train brakes Air
Performance figures
Maximum speed60 mph (97 km/h)
Power output1,200  hp (895 kW)
Tractive effort 40,440  lbf (179.9  kN))
Locale North America
DispositionMost scrapped, sixteen examples preserved

The FM H-12-44 was a yard switcher produced by Fairbanks-Morse from May, 1950–March, 1961. The units featured 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).


A total of 303 units were built for American railroads, 30 were manufactured (between August 1951 to June 1956) by the Canadian Locomotive Company for use in Canada, and 1 unit was exported to Mexico. Initially, H-12-44s were visually indistinguishable from their predecessor model, the FM H-10-44. However, beginning in September, 1952 the Raymond Loewy design elements were removed as a cost-saving measure: 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 possibility of battery explosions. None of the units were produced between May and October 1956, after which time 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 today, 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.

Units produced by Fairbanks-Morse (19501961)

RailroadQuantityRoad numbersNotes
Fairbanks-Morse (demonstrator)
to Yankeetown Dock Corporation 1
Atchison, Topeka and Santa Fe Railway
503–540, 544–564
3 custom built H12-44TS locomotives 541-543. 543 survives today
Ayrshire Collieries Corporation
to Thunderbird Collieries 1;
to Yankeetown Dock 3
Baltimore and Ohio Railroad
196–197, 310–319, 9722–9726
310–319 renumbered 9710–9719,
196–197 renumbered 9720–9721
Canadian National Railway
built by Canadian Locomotive Company
Central of Georgia Railway
Chicago and North Western Railway
1071–1072, 1110–1116
Chicago, Milwaukee, St. Paul and Pacific Railroad ("Milwaukee Road")
1826–1847, 2309–2325
Renumbered 700–710, 715–744, 750–756 (not in order)
Columbia and Cowlitz Railway
Renumbered #700)
Ferrocarril de Chihuahua al Pacífico
Indianapolis Union Railway
Kentucky and Indiana Terminal Railroad
Minneapolis, St. Paul and Sault Ste. Marie Railroad ("Soo Line")
Minnesota Western Railway
to Minneapolis, Northfield and Southern Railway 10
New York Central Railroad
New York, Chicago and St. Louis Railroad ("Nickel Plate Road")
to Norfolk and Western Railway 2134–2155
Pennsylvania Railroad
to Penn Central 8327–8342
Sandersville Railroad
Renumbered 10
St. Louis-San Francisco Railway ("Frisco")
Southern Pacific Company
1486–1491, 1529–1574, 1577–1596
Southern Pacific (Texas and New Orleans Railroad)
to Southern Pacific 1575–1576; renumbered 2373–2374
Tennessee Valley Authority
United States Army
U.S. Steel, Morrisville, Pennsylvania
Wabash Railroad
to Norfolk and Western 3384–3386
White River Lumber Company (Weyerhaeuser Timber Company)  
WTC 1 Weyerhaeuserfmh12-44.jpg
to Pacific Transportation Services 121 then transferred to Northwest Railway Museum where it is preserved in running condition
Yankeetown Dock Corporation


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

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FM H-16-44

The FM H-16-44 was a road-switcher produced by Fairbanks-Morse from April 1950 – February 1963. The locomotive shared an identical platform and carbody with the predecessor Model FM H-15-44, and were equipped with the same eight-cylinder opposed piston engine that had been uprated to 1,600 horsepower (1,200 kW). The H-16-44 was configured in a B-B wheel arrangement, mounted atop a pair of two-axle AAR Type-B road trucks with all axles powered. In late 1950, the AAR trucks were almost exclusively replaced with the same units found on the company's "C-liner" locomotives.

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The FM H-20-44 was a multiple unit-capable end cab road switcher manufactured by Fairbanks-Morse from June 1947 – March 1954, and represented the company's first foray into the road switcher market. The 2,000 hp (1,490 kW), ten-cylinder opposed piston engine locomotive was referred to by F-M's engineering department as the "Heavy Duty" unit. It was configured in a B-B wheel arrangement mounted atop a pair of two-axle AAR Type-B road trucks with all axles powered. H-20-44s shared the same platform and much of the same carbody as the lighter-duty FM H-15-44, which began its production run three months later.

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