The Treaty of Versailles forbid the building of capital ships in Germany but when Hitler came to power in 1933 he discarded the treaty and began construction of the Bismarck and its sister ship, the Tirpitz. Both were more than 800 feet long and 15 stories high, bigger than anything in the British or the French Navies. Their role in the war was less dramatic than Hitler dreamed of. His conception of naval warfare was inherited from World War I, when battleships lined up and slugged it out with one another.
In September, 1940, the Bismarck set sail for the Baltic Sea. Historically, the Bismarck was sunk by the British, who lost the esteemed battleship HMS Hood. The Tirpitz slipped out of its berth and sneaked high up into a Norwegian fjord, where it stayed for the duration. Ironically, until it was sunk late in the war, the Tirpitz played an important role. Her very existence kept many British ships pinned down, just in case the Tirpitz dashed for the open sea. The Tirpitz's threat caused one flotilla of convoy escorts to desert its ships, which were then systematically demolished by U boats, the worst convoy disaster of the war. It took many air raids, and the loss of airplanes, to finally sink the Tirpitz with especially designed bombs call Tall Boys.
Hitler and his admirals had plans for even bigger battleships. They never left the drawing board but the biggest of the series was enormous, about twice the size of Bismarck and Tirpitz. It carried 20-inch cannon. For comparison, the largest US battleships of the war carried 16-inch guns. The most heavily armed battleships were the Japanese Musashi and Yamato and they carried 18 inchers.
Maybe at this point I should editorialize a bit. I don't think anyone needs to be a marine engineer or an architect to appreciate the keen sweep and beauty of these ships. They're aesthetic triumphs. From the clipper bow to the neatly balanced superstructure, they simply LOOK powerful and at the same time display an extraordinary grace. Other battleships in other powerful navies -- British, American, Italian, French, and Japanese -- looked by comparison sluggish and clumsy.
Popular sources tell us accurately that the reason the Brits were able to find and sink the Bismarck is that her steering had been disabled by an air torpedo attack. The rudder was jammed and the Bismarck did nothing but steam in circles, a sitting duck for the several battleships that converged on her. I've always wondered why the propellers themselves weren't used to steer the Bismarck towards safety, jammed rudder or no. This program explains why that was impossible. Both screws were simply too close together. In a sense, backing one engine and using forward on the other canceled the opposing forces out.