Description
In the World War I period, the 4-6-2 Pacific was the favored mainline passenger engine in relatively level territory, so the USRA designs included light and heavy 4-6-2s. The heavy version, designed for trackage that allowed a heavier axle load, was similar in most major dimensions to the existing Pennsylvania K4s and Chesapeake & Ohio F-17 Pacifics. Both had been designed around 1913 and were considered powerful and fast locomotives for their time.
Only 20 government-issue heavy Pacifics were actually built, all of them going to the Erie Railroad. But like most USRA designs, the heavy Pacific was so good that a number of railroads ordered copies after government control ended. The Erie bought 11 more, and at least three of the most successful heavy Pacifics built in the 1920s were based on the USRA design: the Baltimore & Ohio P-7d “President ” class, the C&O F-19, and the Southern Railway Ps-4. A survivor of the latter class resides today in the Smithsonian Institution ’s National Museum of American History in Washington, D.C., resplendent in the Southern ’s famous green livery with gold striping.