The design H40B was another design study made in 1940. Similar to the design H40A, it was based around a main artillery bigger than the 40,6 cm guns of the H39. The general layout of the ship was very similar to the one of the H39 design. The H40B was planned with a mixed propulsion system, diesel engines and steam turbines.

Like the H40A, this design also only reached a very basic level of detail and was not intended to be used for construction.