ALCO S-1 and S-3

ALCO S-1 And S-3

The ALCO S-1 and S-3 were 660 horsepower (490 kW) switcher diesel-electric locomotives produced by ALCO and their Canadian subsidiary Montreal Locomotive Works (MLW). Basically, the two locomotives differed only in trucks, with the S-1 using ALCO's own Blunt trucks, and the S-3 riding on standard AAR type A switcher trucks. The S-1 was built between April 1940 and June 1950, with a total of 540 completed, while the S-3 was constructed between February 1950 and November 1953 (MLW until 1957) with total sales of 292. A modified version, the S-10, was built by MLW only; 13 were built between January and June 1958.