MLW RS-18

4 ft 8+1⁄2 in (1,435 mm) standard gaugePrime moverAlco 251BRPM range1000 (max)Engine typeFour-stroke V12 dieselDisplacement8,016 cu in (131.36 L)GeneratorDC generatorTraction motors4 DC traction motorsCylinders12Cylinder size9 in × 10.5 in (229 mm × 267 mm)TransmissionElectricLoco brakeAir, optional dynamicTrain brakesAir

Performance figures
Power output	1,800 hp (1,340 kW)

Career
Locale	Canada

The MLW RS-18 was an 1,800 hp (1,340 kW) diesel-electric locomotive built by Montreal Locomotive Works between December 1956 and August 1968. It replaced the RS-10 in MLW's catalogue, and production totalled 351 locomotives, to eight customers.

It was the Canadian version of the ALCO RS-11, although MLW did manufacture the RS-11 for Ferrocarriles Nacionales de México.

Canadian National Railway, by far the largest buyer of the RS-18, continued to specify the long hood as the front. By contrast, while all of Canadian Pacific Railway's RS-10s were long-hood-forward, all of their RS-18s were short-hood forward. All of CN and CP's locomotives were delivered with full-height short hoods, as were the first four Pacific Great Eastern Railway, and first Roberval and Saguenay Railway unit. The remaining production was for locomotives with a low short-hood, giving the train crew much better forward vision.

Original owners

Railway	Quantity	Road number	Notes
Canadian National Railway	225	3615–3745, 3830–3893, 3100–3129
Canadian Pacific Railway	72	8729–8800	68 of the 72 were rebuilt in to RS18u's numbered 1800 to 1868
Cartier Railway	8	101–108
International Nickel Company of Canada	3	208-2 – 208-4
Pacific Great Eastern Railway	29	587–599, 614–626, 628–630	578–599 renumbered 601–613; to British Columbia Railway 601–630. They were rebuilt into CRS20's^[1]
Quebec Iron and Titanium	1	6	Renumbered 16
Roberval and Saguenay Railway	2	24, 25
Wabush Lake Railway / Arnaud Railway	11	901–911
Totals	351

Preserved

West Chester Railroad #1803 is an ALCO RS-18 built in 1960 by the MLW for the Canadian Pacific Railway and was numbered 8762. In 1998, it was retired from service by the Canadian Pacific Railroad and was bought by the West Chester Railroad that same year, where it currently remains in service. It was re-numbered as 1803 and repainted into a Brunswick green with a yellow frame stripe.