Design work for the H class began in 1935. It was intended to be very similar to the Bismarck class but with intelligence indicating that the Soviet Union was working on battleships with 16" guns the H class was to be larger. A extended range was needed for fighting in the Atlantic.
In 1937 Hitler ordered that the H class be armed with 16" guns.
The H class were to be built under the Z Plan that was authorized in 1938 as Hitler finally agreed that Great Britain could be a future enemy. He wanted the fleet to be ready by 1945. Rear-Admiral Werner Fuchs was given control of the building program.
In December 1938 the design was finalized and on April 14, 1939 orders were placed for H (yard number 525) and J (981). On May 25 K (264), L (130), M (526), and N (982)were ordered.
With the sudden outbreak of World War II work was suspended on September 30, 1939 and the materials used for U-Boats.
There were to be two catapults for the four aircraft carried.
The main turrets weighed 1,452 tons. The 16" / 40.6 cm SK C/34 guns were manufactured by Krupp. They could fire a 2,271 lb shell 39,800 yards at 30°.
The 5.9" / 15 cm LC/34 guns made up the secondary armament.
The main anti-aircraft guns were 4.1" / 10.5 cm SK C/33.
There were to be underwater torpedo tubes in the H class.
There were twelve MAN diesel engines. Each engine room contained two engines.
Twelve diesel generators provided auxiliary power.