The class S 3/6 locomotives are among the very successful designs in railroad history. These locomotives proved themselves not only in Bavaria, but also in important long distance service beyond the borders of Germany. In the years 1923 to 1930, the German State Railroad ordered additional locomotives from Maffei and Henschel on the basis of the good experience with the locomotive initially designated as the class 18.4. These units were first classified as the S 3/6 and later designated as the class 18.5. Noticeable features on this class were the straight front on the engineer's cab in contrast to the earlier pointed shape for better air flow. Together with the boiler appearing longer, it gave these locomotives a totally different look. The power for the locomotives was increased to 1,830 horsepower.