Rhymney Railway P class

The Rhymney Railway P class was a class of 0-6-2T steam tank locomotives introduced into traffic in 1909 and designed by the Rhymney Railway's engineer C. T. Hurry Riches. They were substantial tank engines, weighing 60 long tons, or 59 long tons after rebuilding, and measuring 35 feet 0 inches in length. The class began with three locomotives, and a fourth was added in 1917. The first batch was built by Robert Stephenson and Company, while the last was built by Hudswell Clarke and differed in having a Belpaire firebox, which earned it the class name P1. Four more were built by Hudswell Clarke in 1921 with superheaters and larger cylinders and were classified AP. Unlike the related M, R and A classes, the P engines were designed for passenger work and had larger driving wheels of 5 feet 0 inches. After the Great Western Railway absorbed the Rhymney, all four were reboilered from 1926 onwards, and the Rhymney designs served as the blueprint for the GWR 5600 class.