The FM H-12-46 was a light road switcher of Fairbanks-Morse design manufactured exclusively by the Canadian Locomotive Company from October, 1951–January, 1953 for the Canadian National Railway. Only thirty of the 1,200 hp, six-cylinder opposed piston engine locomotives were produced. The units (assigned #7600–#7629) were configured in an A1A-A1A wheel arrangement, mounted atop a pair of three-axle trucks.
Externally, they boasted many of the same Raymond Loewy design influences found on the larger and more powerful FM H-16-66 model, some of which were built during the same period. None of the units are known to exist today.
- "Fairbanks-Morse 38D8 Diesel Engine". PSRM Diesel Locomotives. Archived from the original on May 26, 2006. Retrieved January 1, 2006.
- Pinkepank, Jerry A. (1973). The Second Diesel Spotter's Guide. Milwaukee, Wisconsin: Kalmbach Publishing. ISBN 978-0-89024-026-7.
- Kirkland, John F. (November 1985). The Diesel Builders Volume 1: Fairbanks-Morse and Lima-Hamilton. Interurban Press. ISBN 0-916374-69-6.