H-class battleship proposals
The H class was a series of battleship designs for Nazi Germany's Kriegsmarine, which were intended to fulfill the requirements of Plan Z in the late 1930s and early 1940s. The first variation, "H-39", called for six ships to be built, essentially as enlarged Bismarck-class battleships with 40.6 cm (16 in) guns and diesel propulsion.
Source: Wikipedia — H-class battleship proposals (CC BY-SA 4.0)