The LRC (Light Rapid Comfortable or Léger Rapide et Confortable) was a product of the Rail and Diesel Products Division of Le Entreprises de J. Armand Bombardier Ltee (Bombardier or BBD), which had purchased Montreal Locomotive Works (MLW) in 1975, which in turn had been an Alco diesel locomotive licensee since 1948. The project began in 1972 as a joint venture between MLW, Alcan Canada Products, and Dominion Foundries and Steel Co. (DOFASCO). In 1973 MLW constructed a prototype locomotive and coach. The locomotive has a 12-cylinder Model 251F diesel which produced 2900 horsepower, 2000 hp for traction, 900 for auxiliary power (Head End Power, or HEP, for coach heat/air and lighting). The prototype tested for over a year at both the CNR Research Center and the US DOT Test Facility in Pueblo, CO. Although the tests were favorable, orders were not immediately forthcoming. In February 1977 Amtrak entered into a two-year lease-purchase agreement for two trainsets from the Canadian Government, which ordered them from Bombardier. The trainsets consisted of one locomotive and five cars, in accordance with MLW’s recommendation that a single locomotive was sufficient for five cars or less. As a result of the prototype testing, Bombardier made a number of significant design changes, one of which was the use of a 16-cylinder Model 251F diesel rated at 3725 hp, 2700 of which was available for traction. Amtrak’s order was scheduled for delivery in early 1979, but a seven month labor strike at Bombardier caused it to slip into 1980. Also in 1977, VIA Rail Canada, still in its formation stage, issued a solicitation for new high-speed trainsets. Bombardier was selected and an order for 10 trainsets (20 locomotives, 50 cars) was placed for delivery in 1980, but because of the strike, actual delivery began in mid-1981. A series of mechanical problems plagued initial service on the Montreal-Toronto, Montreal-Ottawa, and Toronto-Sarnia service delaying full-scale service into early 1982. VIA classed its trainsets as LRC-2 and numbered the locomotives in the 6900 series. Deliveries on this order were completed in 1982, and the following year VIA placed an order for an additional 10 locomotives and 50 cars, classed LRC-3. The second order was delivered in 1984, and locomotive #6930 had the distinction of being the final locomotive built by Bombardier for domestic service. All have since been retired.

The objectives of the LRC (Light Rapid Comfortable) design were to produce a high-speed, lightweight, low center-of-gravity passenger train that overcame the deficiencies of the sucession of previous designs. Thus, the features of the LRC design were: - Power-banked coaches of 85 foot length, electro-hydraulically tilted up to 10 degrees on curves - Coaches 12 feet high with an underbody clearance of 8 inches, similar in dimensions to the TurboTrain, but with an air bag suspension and heavy acoustic insulation - Coaches constructed primarily of aluminum with a stressed skin exterior for light weight. Their 85 foot length provided greater spaciousness and minimized the claustrophobic feel of their predecessors - Individually-coupled cars, each with a vestibule on one end, providing flexibility for train consists, in both single-ended and double-ended operation - Matching low center-of-gravity locomotives - Train speeds of up to 120 mph, enabling 100 mph terminal-to-terminal speeds on existing mainlines with 4 degree curves. The locomotives were powered by a 16 cylinder 251F prime mover producing 3725 hp total, 2700 available for traction, as the locomotive supplied all of the power for train heating, lighting, and other utilities. This arrangement avoided the use of a separate power unit as existed on many other installations, and thus generated less noise than was typical with separate HEP power plants. But by 1988, VIA's operational assessment of the LRC was more favorable to the cars than the locomotives. Their complex electrical system was particularly cited as failure prone. At that point, VIA's expectation was only a 15-year life for its fleet, and indeed, by 1995 about 20 of the 30 locomotives were in storage. The LRC's only slightly outlived VIA's prediction, the last 7 operational locomotives were retired at the end of 2001.