The FM H-10-44 was a switcher locomotive produced by Fairbanks-Morse from August, 1944–March, 1950. The units featured a 1,000-horsepower (750 kW), six-cylinder opposed piston prime mover, and were configured in a B-B wheel arrangement mounted atop a pair of two-axle AAR Type A trucks, with all axles powered. Many H-10-44s received modifications that increased their horsepower rating to 1,200 hp (890 kW).

FM H-10-44
Milwaukee Road 760, an H-10-44 and the first FM locomotive, preserved in operating condition at Illinois Railway Museum.
Type and origin Power type Diesel-electric Builder Fairbanks-Morse Model H-10-44 Build date August 1944–March 1950 Total produced 195
Specifications Configuration: ​  • 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 2 in (3.10 m) Height 14 ft 6 in (4.42 m) Loco weight 240,000 lb (108.9 t) Prime mover FM 38D-8 1/8 Engine type Two-stroke diesel Aspiration Roots blower Displacement 6,222 cu in (101.96 L) Generator Westhse 481-A Traction motors (4) Westhse 362-D 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 speed 60 mph (97 km/h) Power output 1,000 hp (746 kW) Tractive effort 40,440 lbf (179.9 kN)
Career Locale North America Disposition Three preserved, remainder scrapped, 1 replica on display

The Raymond Loewy-designed carbody featured a slanted nose, sloping hood lines, and (considered to be its most distinguishing feature) a protruding roof visor mounted on the rear of the cab. These styling cues were carried through to the H-10-44's successor, the FM H-12-44, until September 1952 when the exterior design was "Spartanized" to reduce production costs.

A total of 195 units were built for American railroads. Three intact examples of the H-10-44 are known to survive today, all of which are owned by railroad museums. Most notable of these is Milwaukee Road #760 (originally delivered as #1802), the first Fairbanks–Morse locomotive constructed in their own plant, which is preserved and operational at the Illinois Railway Museum. Another example is former Hallet Dock Company HD-11, which is now at the Lake Superior Railroad Museum in Duluth, Minnesota.

A reproduction H-10-44 locomotive sits atop the Wood Family Fishing Bridge, a former railroad bridge which crosses the Rock River several hundred yards south of the foundry where the H-10-44s were built, in Beloit, Wisconsin.