Comparing: O-I vs. VK 36.01 (H)

Development of the superheavy tank was started after the Battles of Khalkhyn Gol in 1939. The vehicle was designed as a maneuverable fire unit that was unprecedented in scale—its hull alone weighted 100 tons. Only one prototype was built, without a turret and made of construction steel. Trials were discontinued due to the unreliable engine; at the end of 1944, the prototype was scrapped. The 15-cm howitzer was to be mounted on the tank after the assemble.

An experimental German WWII heavy tank developed by Henschel. The vehicle was a further development of the VK 30.01 (H) project and a stage in the design process for the Tiger. A total of eight chassis and one prototype were built in 1942. During the development, various technical solutions were trialed. Some of them later served as a basis for German heavy tank designs during the WWII. The chassis was also used in armored recovery vehicles.