USRA standard

The USRA standard locomotives and railroad cars were designed by the United States Railroad Administration, the nationalised rail system of the United States during World War I. 1,856 steam locomotives and over 100,000 railroad cars were built to these designs during the USRA's tenure. The locomotive designs in particular were the nearest the American railroads and locomotive builders ever got to standard locomotive types, and after the USRA was dissolved in 1920 many of the designs were duplicated in number, 3,251 copies being constructed overall. The last steam locomotive built for a Class I railroad in the United States, an 0-8-0 built by the Norfolk and Western Railway, was a USRA design. A total of 97 railroads used USRA or USRA-derived locomotives.

The USRA developed designs for 0-6-0 and 0-8-0 switchers, 2-6-6-2 and 2-8-8-2 Mallet locomotives, and both light and heavy versions of the 2-8-2, 2-10-2, 4-6-2, and 4-8-2 types. The light versions were designed with an axle load of 54,000 lb (24,500 kg) permitting usage on the vast majority of railroads, while the heavy versions were designed to a maximum axle load of 60,000 lb (27,200 kg) for lines with more heavily constructed track.

255 of the USRA 0-6-0 design were built, as well as a great many copies.

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