The ALCO Century 425 was a four-axle, 2,500 hp (1,860 kW) diesel-electric locomotive. 91 were built between October 1964 and December 1966. Cataloged as part of ALCO's "Century" line of locomotives, the C425 was an upgraded version of the C424. The C425 employed the same main generator found in General Electric's U25B model.