Pennsylvania Railroad D16

The Pennsylvania Railroad class D16 was the railroad's final development of the 4-4-0 American type of steam locomotive. A total of 429 were built at the Juniata Shops in five subclasses, some with 80 inch driving wheels for level country and others with 68 inch drivers for mountain grades. Designed as an enlargement of the earlier class P, later D14, they broke with the traditional low slung layout by placing a large Belpaire firebox above the frames and a high boiler, which gave an exceptional high speed ride. Construction continued until 1910, and a superheater rebuild program from 1914 kept large numbers in service until the 1930s. The last were retired in 1953, and number 1223 is preserved at the Railroad Museum of Pennsylvania.