These locomotives began life as MLW RS-18s for the Canadian National Railway (CN).
This engine turned a General Electric (of Peterborough, Ontario) DC generator feeding four traction motors - one per axle on two bogies.
They continue in branchline and secondary service throughout North America today (April 2009).
Using the RS-18 as a starting point, the RSC-14 was created in the mid-1970s to meet CN's requirement for A1A-A1A trucked locomotives for light rural branchline service, particularly in the Maritimes.
The locomotives saw extensive use on Prince Edward Island (see Prince Edward Island Railway), and on branch lines in New Brunswick and Nova Scotia.