 Because the Deutsche Reichsbahn suffered from a great shortage of coaches following the ceasefire reparations at the beginning of the 1920s, in 1921 new passenger coaches were built based on standard designs, the so-called "Einheitsbauart".Although a steel design was called for from the outset, most of the coach factories could not immediately change their production lines, so that the vast majority of the coaches in the first delivery batches were still built with wooden coach bodies.Between 1921 and 1923, 90 iron and 2,639 wooden coaches entered service.