Atlanta-class cruiser

USS Atlanta
Class overview
Name:	Atlanta-class cruiser
Operators:	United States Navy
Preceded by:	St. Louis class
Succeeded by:	Cleveland class Juneau class
Subclasses:	Oakland class
In commission:	1941–49
Completed:	8
Lost:	2
Retired:	6
Preserved:	0
General characteristics
Class and type:	Light cruiser
Displacement:	6,718 long-tons (standard); 7,400 long-tons (loaded)
Length:	541 ft 0 in (164.90 m)
Beam:	52 ft 10 in (16.10 m)
Draft:	20 ft 6 in (6.25 m)
Propulsion:	4 × 665 psi boilers 2 geared steam turbines 75,000 hp (56 MW)
Speed:	32.5 knots (60 km/h)(design), 33.6 knots (62 km/h) (trials)
Range:	8,500 nautical miles (15,700 km) at 15 knots (28 km/h)
Complement:	Officer: 35 Enlisted: 638; Oakland group(CL 95-99) Officer: 47 Enlisted:766
Armament:	As designed 16 × 5 in (127 mm)/38 cal guns 16 × 1.1 in (27 mm)/75 cal guns 6 × 20 mm/70 cal anti-aircraft cannons 8 × 21 in (533 mm) torpedo tubes Oakland group (CL 95-99) 12 × 5 in (127 mm)/38 cal guns 8 × 40 mm/56 cal anti-aircraft guns 16 × 20 mm/70 cal anti-aircraft cannons 8 × 21 in (533 mm) torpedo tubes
Armor:	Belt: 1.1–3.5 in (28–89 mm) Deck: 1.25 inches (32 mm) Turrets: 1.25 inches (32 mm)

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 four Oakland and later ships had slightly different armament as they were further optimized for anti-aircraft fire. The Atlanta class had 12 x 5-inch (127 mm)/38 caliber guns, mounted in three superfiring sets of two-gun turrets fore and three more aft. The first four ships of the class also had an additional two twin 5-inch/38 mounts, one port and one starboard, giving these first four Atlanta-class cruisers the heaviest anti-aircraft armament of any cruiser of World War II.

The Atlanta class saw heavy action during World War II, collectively earning 54 battle stars. Two ships of the class were sunk in action: Atlanta and Juneau, both at the Naval Battle of Guadalcanal. The other six were decommissioned shortly after the war and were scrapped in the 1960s.

As built the original main gun battery of the first quartet of Atlanta class was composed of eight dual 5-inch/38 caliber gun mounts (8 × 2 5-inch guns). This battery could fire over 17,600 pounds (8,000 kg) of shells per minute, including the radar-fuzed "VT" anti-aircraft (AA) 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-inch (28 mm)/75 caliber guns in three quad mountings, initially without directors fitted. By early 1942 as more became available a fourth 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.

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Wikipedia