The PRR C1 was the Pennsylvania Railroad's class of 0-8-0 steam locomotive, used in switching service. The 0-8-0 was common on most railroads, but not on PRR; when the railroad needed bigger motive power, they used the 2-8-0 "Consolidation". PRR wanted the best motive power to handle the switching chores at yards and interchanges and the C1 class was the heaviest two-cylinder 0-8-0 switcher ever produced. Calculated tractive effort was 76154 lb, based on 78% MEP with 60% maximum cutoff. The C1s were retired between 1948 and 1953.