Really huge indeed.
According to Battleships, Carriers and all other Warships (
http://warships1.com/default.htm), there was indeed such a project, the H project, but the data you found seems to have been glossing over a few elements.
Some data :
Original Plan : a battleship of a "mere" 52 000 tons, with 15.9 guns, in effect a ship very much like the Bismarck.
Hitler later demanded that the gun power be increased to 16.53 to match the USN battleships.
Yet later, he ordered it raised to impossibly huge 31.5 guns! For a comparison, the largest naval guns used were the 18 inch guns of the Yamato. Hitler was later convinced to relent, and the last design idea to be considered before the project was scrapped had "mere" Yamato-level guns.
The last design actually intended to be built (H-41) weighted around 65-69 000 tons, which would have put it ahead of the Japanesse Yamato-class as largest battleship ever.
The H42 to 44 were simply tests in terms of how armor could deal with air attacks, and not intended to be built. Had it been built, the H44 would have weighed in as a 118 104 tons displacement (full load). Not quite "three bismarcks" (50 000 tons at full load), but still quite the monster.
Here are the displacement at full load of the last serious (not considering the H42-H44 lot) projects of the various nations :
Japan : "Super-Yamato" : 100 000 tons, 8 x 20 inch guns (4 twin turrets) (Delusions of Grandeur? Nahhhhhhhhhhhhhh *sarcasm*)
America : Montana-Class : 73 500 tons, 12 x 16 inch guns. (4 triple turrets)
Germany : H41 : 69 000 tons, 8 x 18 inch guns. (4 twin turrets)
UK : Lion II Class : 55 000 tons, 9 x 16 inch guns (3 triple turrets)
if you think about that a really huge boat
