In order to be able to haul the ever heavier freight trains on the Württemberg network without double-heading, the class K with a 2-12-0 wheel arrangement of was procured from Maschinenfabrik Esslingen from 1917 onwards. They were the only twelve-coupled locomotives in Germany. The reason for the large number of wheel sets was that the axle load was limited to 16 tonnes and it would therefore not have been possible to build a sufficiently powerful locomotive with an 0-10-0 or 2-10-0 wheel arrangement.