The FM H-12-44 was a yard switcher 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.