But because the development order was not given by the Deutsche Reichsbahn and because different construction conventions were followed in some cases, these were not seen as Einheitsloks, the standard locomotives produced by the DR between the wars.

As a result of the outbreak of World War II, however, only the prototyped of the 1'C1' version was built in 1939 by Krupp; orders for the other engines were cancelled.

After the re-joining of the two lines in 1983/1984 it was once again used for duties on the Harz Railway, for example to head the first scheduled passenger train between Gernrode and Hasselfelde via Stiege on 3 June 1984.

The two outside cylinders, which are slightly tilted to cope with the constraints of the rail gauge, are driven by Heusinger valve gear with Kuhn slides.

These gave better running performance when the locomotive was free-running (Leerlauf) and the regulator was closed, because they practically relieve the cylinder of its job as an air pump when the steam pressure is released.