Pennsylvania class A5s

The PRR had lots of tracks on streets and on industrial property with tight curves, where even locomotives with three sets of drivers had problems. So they were probably the last US railroad to design a huge standard gauge switcher with the wheel arrangement 0-4-0 in 1916. After the older class A4, the new A5s was superheated and 7,000 pounds heavier. This made it the heaviest two-axle locomotive ever. It had Walschaerts valve gear, piston valves and larger cylinders at 20 by 24 inches. The firebox was of the Belpaire type typical for the PRR and its grate was larger than that of the USRA 0-6-0 at 38.33 square feet. By 1924, the Juniata works at Altoona had completed 47 locomotives. They started to be replaced by diesel switchers in the late forties. The last one was retired in 1957 and 94 is the only one that was preserved. Today one can find it in the Railroad Museum of Pennsylvania in Strasburg.