The USS Alaska (CB-1) was an Alaska-class large cruiser which served with the United States Navy during World War II. Ships of the Alaska class had a main battery much heavier than those of normal heavy cruisers, but were lighter and faster than most battleships, unofficially classified as battlecruiser. They were built on a "cruiser hull," more slender than a battleship design of similar length (all of the World War II battleships, including the South Dakota class which were over 100 feet shorter in length, had an additional 17 feet in beam). The main battery and superstructure resembled those of a battleship, using a "2-A-1" gun layout and the massive tower mast that was used in all American World War II battleships. However, the 5" secondary was more similar to that of a heavy cruiser, with only six twin 5" mounts, four on the superstructure corners and the remaining two superfiring over the #2 and #3 12" turrets.