|
The ''Atlanta''-class cruisers were eight United States Navy light cruisers originally designed as fast scout cruisers or flotilla leaders, but later proved to be effective anti-aircraft cruisers during World War II. They were also known as the ''Atlanta''-''Oakland'' class. The ''Oakland'' and later ships had slightly different armament as they were further optimized for anti-aircraft fire. With 8 dual 5 inch/38 caliber (127 mm) gun mounts (8 × 2 5-inch guns), the first run of ''Atlanta''-class cruisers had by far the heaviest anti-aircraft armament of any cruiser of World War II. Two ships of this class were sunk in action: and , both at the Naval Battle of Guadalcanal. The other six were deactivated shortly after the war and were scrapped in the 1960s. ==Specifications== As built the original main gun battery of the first quartet of ''Atlanta''-class was composed of eight dual 5 inch/38 caliber (127 mm) gun mounts (8 × 2 5-inch guns). This battery could fire over of shells per minute, including the radar-fuzed "VT" antiaircraft shells. Fire control was by two Mk 37 fire control systems located on the centerline atop the superstructure. As built these lacked radar but in 1942 radar FD (Mk 4) was fitted. From 1943 this was replaced by the improved Mk 12/Mk 22 combination. The first four had an original secondary anti-aircraft armament of twelve 1.1 in guns in three quad mountings, initially without directors fitted. By early 1942 as more became available a 4th quad mount had been installed on the quarterdeck and directors were fitted (probably Mk 44). By late 1942 these troublesome and relatively ineffective weapons began to be replaced in the surviving ships by twin mountings for the new and far superior Bofors 40 mm anti-aircraft guns with Mk 51 directors. Also from early 1942 close-range AA armament was augmented by eight 20 mm rapid-fire anti-aircraft cannons in single Mk 4 mountings disposed two on the forward superstructure, 4 amidships between the funnels (displacing some of the ships boats) and 2 on the quarterdeck aft. From 1943 onward the number of these mounts increased by adding two more on the forward superstructure and a pair each side of the second funnel to counter the danger of Japanese air attacks (especially ''kamikazes''). From the end of 1943, a quadruple 40 mm Bofors mounting replaced the twin mount on the quarterdeck, with the six depth charge projectors being removed as compensation. The additions of radar, additional close-range anti-aircraft guns and other equipment seriously impaired the stability of these ships as the war progressed and resulted in overcrowding as more ratings had to be added to man them. The second group, sometimes known as the class was commissioned with only six twin 5"/38 mounts and with Bofors guns from the start, with four additional twin Bofors 40 mm mounts compared to their predecessors: 2 displacing the former 5"/38 wing turrets (improving both stability and close-range AA firepower while easing congestion) and two between the funnels displacing the previous two pairs of 20mm Oerlikon's. In addition the battery of 20 mm anti-aircraft cannons was increased with a pair on the bow, 4 on the forward superstructure, 8 amidships arrayed either side of the aft funnel and 2 on the quarterdeck aft for a total of 16. By the end of the war USS ''Oakland'' had been given an anti-kamikaze upgrade which included replacing the 4 aft twin Bofors with quad mountings and greatly reducing the number of 20 mm mounts (possibly as few as 6) while replacing those that remained with twin rather than single guns. Torpedo tubes were removed. Photo evidence show that USS ''Renos torpedo tubes had been removed by the time she was torpedoed on 3 November 1944. The ''Atlanta''-class cruisers were the only class of U.S. Navy cruisers commissioned during World War II to be armed with torpedoes tubes, with eight 21" torpedo tubes in two quad launchers. Although ships of the class were planned as destroyer flotilla leaders, the original design did not include anti-submarine armament such as sonar or a depth charge battery, In early 1942 along with anti-aircraft and radar upgrades these ships were fitted with sonar and the standard destroyer battery of 6 depth charge projectors and 2 stern mounted tracks. When the vessels were determined to be more valuable as protection against aircraft, the projectors were removed but the tracks were retained. The ''Oakland'' sub-class never received the projectors, getting only two stern tracks, probably due to marginal stability. Radar was not fitted as built. From spring of 1942 these ships were re-fitted first with SC-1 and SG search and FD (Mk 4) for fire control. As the war progressed additional and more modern radars were added. The class was powered by four 665 psi boilers, connected to 2 geared steam turbines producing , and the ships could maintain a top speed of . On trial the Atlanta made and . The ships of the ''Atlanta''-class had thin armor: a maximum of on their sides, with the captain's bridge and the 5-inch gun mounts being protected by only .〔 The ships were originally designed for 26 officers and 523 men, but this increased to 35 officers and 638 men with the first four ships, and 45 officers and 766 men with the second group of four ships beginning with ''Oakland''. The ships were also designed as flagships with additional space for a flag officer and his staff but the additional space was used for additional crew necessary to man anti-aircraft weapons and electronics. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Atlanta-class cruiser」の詳細全文を読む スポンサード リンク
|