The 1.1"/75 caliber gun was an American anti-aircraft weapon of World War II, used by the United States Navy. The name means that it had a bore diameter of 1.1 in (28 mm) and barrel caliber of 75. The gun was designed to replace the M2 Browning and four barrels were required to duplicate the rate of fire.
Quadruple-mount 1.1-inch (28 mm) anti-aircraft cannon aboard the battleship USS Pennsylvania during World War II
1.1" mounts firing aboard USS Hornet (CV-8), May 1942.
1.1" mount aboard USS Enterprise (CV-6), 1942.
North Carolina-class battleship
The North Carolina class were a pair of fast battleships, North Carolina and Washington, built for the United States Navy in the late 1930s and early 1940s.
North Carolina underway on 3 June 1946. By this time, many of the light anti-aircraft weapons (Bofors 40 mm and Oerlikon 20 mm) mounted during the war had been removed, while more modern radars had been mounted on its fore and main masts.
North Carolina seen from the air on 17 April 1942
North Carolina fires a three-gun salvo from its number one turret
The 32,250-long-ton (32,770 t) design "A" was one of the first proposals. Unlike "B" and "C", it was far below the treaty-mandated limit of 35,000–tons. It would have carried nine 14-inch guns in its main battery; although all of the turrets were forward of the superstructure, the guns could still fire forward provided that they were elevated to 4.5 degrees or more. The secondary battery planned was twelve 5-inch (127 mm) were unusually arranged in triple mounts.