From 1907 onwards, the PRR started with procuring 540 Consolidations of classes H8 to H8c, most of which were still operated with saturated steam. In addition, 146 of them had already been built as H8sb or H8sc with superheaters. Most of the others were also soon superheated. From 1913 onwards, 274 H9s and 273 H10s followed, all of which had a superheater from the factory, most of which were similar to the superheated H8 and differed in the size of the valve ports. In addition, 312 H8 were rebuilt into H9s and 200 more H8 were rebuilt into H10s. Baldwin, the ALCO plants in Pittsburgh and Brooks, and the PRR Juniata shops in Altoona were involved in the production of the individual variants. The retirements began in 1933 and were completed by 1960. 