American Locomotive Company developed the C630 in response to General Motors' SD-40 locomotive, and Norfolk & Western Railway purchased 10 of them in 1966-1967. Built in 1967, C630 #1135 originally served in regular freight service. These locomotives were the only ones among the 77 C630s produced by ALCO between 1965-1967 to be designed with high, short hoods. In the 1970s, they were coupled to slugs, unpowered rail equipment that increased traction, and were used in hump yard service at Norfolk & Western yards in Portsmouth, Bluefield, Roanoke, and Norfolk, and later in Bluefield, Roanoke, Lamberts Point, and Portsmouth, Ohio. Painted in Pevler Blue, a color named for Norfolk & Western President Herman Pevler, #1135 reflected a repainting program during his 1963-1970 administration in which black Norfolk & Western engines were changed to a blue similar to that used on the Wabash, a railroad he had previously led before its 1964 lease by Norfolk & Western. The C630's most distinctive feature was its large aftercooler radiator housing above the roofline, whose radiators boosted performance under heavy load. Because these engines had high maintenance costs, Norfolk & Western unsuccessfully tried to sell them to the Chicago and Northwestern Transportation Company before converting them to hump yard slug masters. Four C630s still exist.