A treasure trove of vital German intelligence, the submarine's capture was top-secret. See inside the U-boat, now a permanent exhibit at Chicago's Griffin Museum of Science and Industry.

It was effectively an enlarged crewed torpedo, combining in its design engineering solutions typical for torpedoes and for midget submarines ... according to data. See the 10 worst.

A treasure trove of vital German intelligence, the submarine's capture was top-secret. See inside the U-boat, now a permanent exhibit at Chicago's Griffin Museum of Science and Industry. Submarine ...