New Orleans Class Cruiser - Armament

Armament

The main armament on the class centered on nine 8in/55 caliber Mark 14 guns, mounted in triple turrets. The New Orleans was fitted with Mark 14 Mod 0 guns, the Minneapolis with the Mark 15 Mod 1 guns and the remaining ships of the class received Mark 12 Mod 0 guns. The turret face configurations were also different with the Mark 14 guns being housed in rounded face turrets and the Mark 12 and 15 guns in a flat faced turret. The 8in guns had a range of 31,700 yards (29,000 m) with a muzzle velocity of 2,800 feet per second (850 m/s). The armor piercing round weighed 260 pounds (120 kg) and could penetrate five inches of armor plating at 10,000 yards (9,000 m). Secondary armament for the class consisted of eight 5in/25 caliber dual purpose guns, which could be used against surface and aerial targets, as well as .50 caliber water-cooled machine guns to augment the 5in guns. When the US entered the war in December 1941, the New Orleans class and other "Treaty" cruisers were rushed into battle with little modification and lacking in air defense. The Japanese proved at Pearl Harbor that this war would be decided with air power. As soon as available, the quadruple 1.1in machine guns and the Swiss-designed 20 mm Oerlikon cannon (which would replace the .50 caliber guns) were fitted, as well as early radar units and fire control directors. As the war progressed, developments in radar abilities gave the Allies an increasingly decisive advantage over the enemy. Late 1942 saw the arrival of the Swedish 40 mm Bofors which was mounted in twin and quadruple mountings and would replace the quadruple 1.1-inch machine guns which proved ineffective. By late 1945, even after the removal of many non-essential items (half of their spotter planes as well as a crane and a catapult became non-essential due to advances in radar) the ships became dangerously over weight because of new weaponry and electrical and radar equipment. The threat from the air was so intense this condition had to be tolerated.