In the second half of the thirties the Germans began to prepare a design of new, Type 1937, destroyers, with better seakeeping qualities and greater radius. They were to be armed with 15 cm guns, with more hitting power. As the design work proceeded slowly, in April 1938 it was decided to build eight ships of Type 1936A - similar to Type 1936, but larger and armed with 15 cm guns. After the war broke out further 12 almost identical boats were ordered as Type 1936A (Mob), named Z 31 to Z 42.
The general design was similar to the predecessors, but several effords were made to increase the seagoing capabilities. The single rudder was replaced by a twin rudder and the bow section was modified. But when sailing through heavy seas, it soon got obvious that the new bow section was ill designed, and the ships took over too much water. This problem even got worse after the new twin turrets were installed and it took a very long time until it got clear that the new stern design had caused all the problems.
During the war, the surviving ships were refitted with additional Flak guns (Project name "Barbara") since the original armament proved to be not adequate.