The ALCO Century 630 is a model of six-axle, 3,000 hp (2.2 MW) diesel-electric locomotive built by the American Locomotive Company (ALCO) between 1965 and 1967. It used the ALCO 251 prime mover. 77 were built: 3 for Atlantic Coast Line Railroad, 4 for Chesapeake and Ohio Railway, 8 for Louisville and Nashville Railroad, 10 (with high noses) for Norfolk and Western Railway, 15 for Pennsylvania Railroad, 12 for the Reading Company, 15 for Southern Pacific Railroad and 10 for Union Pacific Railroad.