The Century 424 was a four-axle, 2,400 hp (1,790 kW) diesel-electric locomotive of the road switcher type. 190 were built between April 1963 and May 1967. Cataloged as a part of Alco's Century line of locomotives, the C424 was intended to replace the earlier RS-27 model and offered as a lower-priced alternative to the C425. Montreal Locomotive Works also built this locomotive as MLW Century 424.