Comparing: O-I vs. Heavy Tank No. VI

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.

In 1943, the Japanese ambassador to Germany attended Henschel's field trials of the Tiger. After that, the company was ordered to transfer all tank documentation to Japan. One disassembled Tiger was sent to Bordeaux on October 14, 1943, to be delivered to Japan by submarine. However, the vehicle was never delivered, and the Japanese were never able to establish their own production of Tigers. This enterprise cost 645,000 Reichsmarks to Japan, while the original cost was 300,000 Reichsmarks.