These engines had inside frames and Allan valve gear and were delivered in three series, that differed from one another in their dimensions. The original classification D was adopted by the Royal Bavarian State Railways (Königlich Bayerische Staatsbahn) and amended to D IV. Initially all the engines were taken over by the Deutsche Reichsbahn. However, only six vehicles were given running numbers (88 7021–7026). By the late 1920s they were all either retired or sold.