The C1a Class were a type of 4-4-4

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, Fuel oil, oil or, rarely, Wood fuel, wood) to heat ...

built for the

Philadelphia and Reading Railway The Reading Company ( ) was a Philadelphia-headquartered rail transport, railroad that provided passenger and freight transport in eastern Pennsylvania and neighboring states from 1924 until its acquisition by Conrail in 1976. Commonly called th ...

in 1915. Four locomotives were built, road numbers #110-113. They used front and rear trucks that were effectively identical. During a year of operation, they proved to be quite unstable; after that year, they were rebuilt to 4-4-2 "Atlantic" locomotives, reclassified as P7sa, and renumbered #350-353.

References

Steam locomotives of the United States 4-4-4 locomotives 2′B2′ steam locomotives Philadelphia and Reading Railroad locomotives Railway locomotives introduced in 1915 Standard-gauge locomotives of the United States {{steam-loco-stub