| Pennsylvania Railroad C1 | |
| Powertype: | Steam |
| Builder: | Pennsylvania Railroad |
| Builddate: | 1925, 1927 |
| Totalproduction: | 90 |
| Whytetype: | 0-8-0 |
| Uicclass: | Dh |
| Driverdiameter: | 563NaN3 |
| Axleload: | 740001NaN1 |
| Locoweight: | 2780001NaN1 |
| Fueltype: | Coal |
| Boilerpressure: | 2502NaN2 |
| Cylindercount: | Two |
| Cylindersize: | 27x |
| Valvegear: | Walschaerts |
| Valvetype: | Piston |
| Tractiveeffort: | 761541NaN1 |
| Fleetnumbers: | 6550–6639 |
| Retiredate: | 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.