Pennsylvania Railroad C1
PRR C1 locomotive #6560. Photographed at Louisville, KY, 28 June 1950 by Otto Perry
Type and origin Power type Steam Builder Pennsylvania Railroad Build date 1925, 1927 Total produced 90
Specifications Configuration: ​  • Whyte 0-8-0  • UIC Dh Gauge 4 ft 8+1⁄2 in (1,435 mm) Driver dia. 56 in (1.422 m) Axle load 74,000 lb (33.6 t) Loco weight 278,000 lb (126.1 t) Fuel type Coal Boiler pressure 250 psi (1.72 MPa) Cylinders Two Cylinder size 27 in × 30 in (686 mm × 762 mm) Valve gear Walschaerts Valve type Piston
Performance figures Tractive effort 76,154 lbf (338.7 kN)
Career Numbers 6550–6639 Retired 1948–1953 Disposition All scrapped

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". The PRR wanted the best motive power to handle the switching chores at rail yards and interchanges, and the C1 class was the heaviest two-cylinder 0-8-0 switcher ever produced. Calculated tractive effort was 76,154 lb, based on 78% MEP with 60% maximum cutoff. All C1s were retired between 1948 and 1953, none being preserved.