The Pacific War Online Encyclopedia

New Orleans Class, U.S. Heavy Cruisers

Photograph
of USS New Orleans

Schematic diagram of New Orleans
class heavy cruiser

ONI 222

Tonnage	10,136 tons standard displacement
Dimensions	588' by 61'9" by 21'9" 179.22m by 18.82m by 6.63m
Maximum speed	32.4 knots
Complement	868
Aircraft	2 catapults 4 seaplanes
Armament	3x3 8"/55 guns 8x1 5"/25 AA guns 4x4 1"/75 AA guns 8x1 0.50 machine guns
Protection	1520 tons: 5" (127mm) belt tapering to 3" (76mm) on 0.75" (19mm) STS plating 3" (76mm) machinery bulkheads tapering to 2" (51mm) 4.7" (119mm) magazine sides tapering to 3" (76mm) 1.5" (38mm) magazine bulkheads 2.25" (57mm) armor deck 8"/1.5"/2.25" (203mm/38mm/57mm)) turret faces/sides and rear/roof 5" (127mm) barbette 2.5" (64mm) conning tower
Immune zone	12,000 to 24,000 yards (11,000 to 22,000 m) against 8" (205mm) gunfire
Machinery	4-shaft Westinghouse geared turbine (107,000 shp) 8 Babcock & Wilcox boilers
Bunkerage	1861 tons fuel oil
Range	10,000 nautical miles (19,000 km) at 15 knots
Modifications	1942-4: Splinter shields added to 5" gun positions. 0.50 machine guns replaced with 6x1 20mm Oerlikon AA guns. Equipped with SC and Mark 3 radar. 1942-10: Light antiaircraft increased by up to 10x1 20mm guns. Late 1943: 1.1" guns replaced with 6x4 40mm Bofors AA guns. SC radar replaced by SG (two sets), SK, and Mark 4 radar. Conning tower removed to reduce top weight. 1944-1945: Light antiaircraft increased by another 16x1, 14x2 20mm guns.

The New Orleans were completed in 1934-1937. By the time they were being designed, in 1929, the Navy had recognized that its earlier heavy cruisers were underweight, and the new ships were given heavier protection to bring them up to the treaty limit. They were somewhat shorter and less beamy than the Portlands, at the cost of being less well subdivided, but this allowed a shorter armor belt of greater thickness. Because their machinery was not particularly well-dispersed, they were theoretically vulnerable to a loss of power if a torpedo struck the bulkhead between the two engine rooms. Unlike earlier designs, their 8” (203mm) guns were mounted in proper turrets and could be elevated individually.

Except for the single Wichita, they were the most modern heavy cruisers with which the Navy began the war. They were quite heavily armed and armored, to the extent that they often found themselves employed in a “pocket battleship” role.

Three ships of this class were sunk in a single disastrous night in the Battle of Savo Island.

Units in the Pacific:

New Orleans	Pearl Harbor
San Francisco	Pearl Harbor
Minneapolis	Task Force 1 south of Oahu
Astoria	Task Force 12 en route to Midway from Oahu	Sunk by gunfire 9 August 1942 off Guadalcanal
Vincennes	Arrived 1942-3-11	Sunk by gunfire 9 August 1942 off Guadalcanal
Quincy	Arrived 1942-6-10	Sunk by gunfire 9 August 1942 off Guadalcanal
Tuscaloosa	Arrived 1942-12