New Orleans class cruiser (1931)

USS New Orleans (CA-32)
Class overview
Name:	New Orleans class cruiser
Operators:	United States Navy
Preceded by:	Portland-class cruiser
Succeeded by:	Wichita-class cruiser
Completed:	7
Lost:	3
Retired:	4
Preserved:	0
General characteristics
Type:	Heavy Cruiser
Displacement:	9,950 tons
Length:	588 ft 2 in (179.27 m)
Beam:	61 ft 9 in (18.82 m)
Draft:	19 ft 5 in (5.92 m)
Propulsion:	4 × Parsons/Westinghouse geared turbines 8 × Babcock & Wilcox boilers 4 × screws 107,000 hp (80,000 kW)
Speed:	32.7 knots (60.6 km/h; 37.6 mph)
Complement:	708 officers and enlisted
Armament:	9 × 8 inch/55 caliber guns 8 × 5 inch/25 caliber guns[1] 8 × .50 caliber machine guns
Armor:	3-5 inch belt 1.25-2.25 inch deck 1.5-8 inch turrets 5 inch barbettes (6.5 inch barbettes in CA 38) 5 inch CT

The New Orleans class cruisers were a class of seven heavy cruisers built for the United States Navy (USN) in the 1930s, the last built under the Washington Naval Treaty before World War II. They were an improvement on the Northampton class heavy cruisers. New Orleans, Astoria, and Minneapolis were originally ordered as Northampton class ships but shortly after having their keels laid were reordered as Astoria class cruisers. The Portland (CA-33) and Indianapolis (CA-35) could not be changed to the New Orleans design and became the Portland class.

Design

The New Orleans class design was a test bed for new innovations in cruiser design, which is why there were three distinct designs within this class.

• Design #1: New Orleans, Astoria, and Minneapolis.
• Design #2: Tuscaloosa and San Francisco.
• Design #3: Quincy and Vincennes.

This class was the direct ancestor for all subsequent USN gun cruisers. From them came the Brooklyn, Wichita, Cleveland, and the Baltimore class cruisers. While the Washington Naval Treaty was still being observed, new technology was implemented in the New Orleans class because the USN knew that if and when war came, they would need this knowledge to build ships (which were already in the planning stage) beyond the treaty limits. The USN came to the conclusion that no 10,000 ton cruiser could adequately perform the roles given.

Originally the USS Astoria (CA-34) was the lead ship of this class, but the Astoria received a later hull number than the New Orleans because she was launched later, even though she was laid down first. The class was renamed due to the sinking of the Astoria at the Battle of Savo Island in 1942.

Immediately following the Guadalcanal Campaign the remaining ships of the class went through major overhauls in order to lessen top heaviness due to new electrical and radar systems (as well as more anti-aircraft weaponry) which was being added as technology advanced. In doing so, the ships took on a new appearance, most notably in the bridge area and became known as the New Orleans-class.

Three ships of the class (Astoria, Quincy, and Vincennes) were lost in the war, all in the Battle of Savo Island in 1942. The four survivors were decommissioned shortly after the war ended, and scrapped in 1959-1961.

Armor

1943 ONI identification image for the New Orleans-class.

The seven ships of the New Orleans class were the penultimate US Navy cruisers, with the exception of the Wichita, to be built to the standards and limitations of the Washington Naval Treaty of 1922. Design of the new warships were begun in early 1929, based on the three preceding classes: The Pensacola, the Northampton and the Portland class. All of the cruisers of the New Orleans class were outwardly similar but the displacement among these ships varied by some 600 tons. The Bureau of Construction and Repair authorized a contemporary 8 inches (200 mm) gun cruiser design of smaller size, but one which allocated considerably more tonnage towards protection. The New Orleans class was noteworthy for its protection. The hull was 12 feet (3.7 m) shorter than a Northampton, with a shorter armor belt that protected only the machinery and other internal spaces, allowing its thickness to be increased to 5 inches (130 mm). The machinery bulkheads were given 3.5 inches (89 mm) and the deck armor was strengthened to 2.5 inches (64 mm). For the first time in US cruisers, barbette and turret armor was sufficient to withstand 8 inch shellfire. The turrets were faced with 8 inches of armor, 2.75 inches (70 mm) on the sides and 1 inch (25 mm) on the roof. The barbettes were protected with 5 in of armor on all ships except the San Francisco, whose barbettes were fitted with 6.5 inches (170 mm) of armor.

Magazine protection was increased to 4 inches (100 mm). Magazine protection was further increased by placing them well below the waterline. Otherwise only an internal splinter belt and the armor deck protected the magazines. While this allowed an exceptional degree of armored protection for the vitals against shellfire, there was little protected hull volume, and the deep magazines were more exposed to underwater damage (The New Orleans learned this the hard way at the Battle of Tassafaronga). Protection represented approximately 15% of normal displacement as opposed to the only 5.6% in the Pensacolas and 6% in the Northampton and Portland classes. Unfortunately, fuel bunkerage had to be reduced, which resulted in a smaller operational range. This percentage increase in protection is deceiving, as the Savo Island battle showed. Astoria, Vincennes, and Quincy were quickly sunk by shells and torpedoes from attacking Japanese ships, their armour being easily pierced.

Armament

The main armament on the class centered around 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.

Appearance & Performance

Outwardly, the New Orleans ships had a distinctive appearance and were considered very good looking vessels^{[citation needed]}. The forecastle deck extended back to the second funnel and the main superstructure was constructed without the ungainly tripod mast seen on the previous cruisers. The bow was a raked type, similar to those of British cruisers. The two funnels were situated closer together with a large search light tower in between. Aircraft handling facilities were moved further aft and a larger second conning station erected above the hangar. A single mainmast was erected there, between two huge pedestal cranes which handled both spotter planes and small craft. The main 8 inch turrets, although armored, were actually smaller with a more effective angular faceplate. By enlarging the forecastle deck, the secondary battery of 5 inch guns were mounted closer together, facilitating a more efficient ammunition delivery. Power was provided by eight Babcock and Wilcox high-pressure steam boilers that produced 107,000 hp (79,800 kW) for the four Westinghouse gearing steam turbines. The turbines were shafted to four screws, giving this class a rated speed of 33 knots (61 km/h). The cruisers' range - using 3,269 long tons (3,321 t) of bunker oil - was approximately 14,000 nautical miles (26,000 km) at 10 knots (19 km/h) or 5,280 nautical miles (9,780 km) at 20 knots (37 km/h). Their range could be extended by refueling from a tanker or another ship fitted to transfer oil while underway. The New Orleans cruisers performed peacetime exercises well with no serious shortcomings being found. While many changes were implemented to improve their performance and especially their protection, the 10,000 ton limit of the Washington Naval Treaty was not exceeded. The new cruisers were considered successful in their own right but could not be considered equal to some foreign contemporaries, which were often considerably larger.

Ships in class

• New Orleans (CA-32)
• Astoria (CA-34)
• Minneapolis (CA-36)
• Tuscaloosa (CA-37)
• San Francisco (CA-38)
• Quincy (CA-39)
• Vincennes (CA-44)

World War II

For almost four years, the ships of the New Orleans class were assigned to the most urgent of front line duties, and thus, became involved in more than their share of deadly action. The Astoria, Quincy and Vincennes were quickly sunk in the Battle of Savo Island, 8 Aug – 9 Aug 1942. Although three of their number were lost, the ships proved to be well designed. The tragic loss of the three cruisers in no way reflects on the battle worthiness of these ships. The New Orleans, Minneapolis and San Francisco were also seriously damaged in early war engagements in the Pacific. These engagements included the Naval Battle of Guadalcanal, in which the San Francisco engaged enemy ships at point blank range, and the Battle of Tassafaronga where the Minneapolis took two Long-Lance torpedoes, one to the port bow, the other in her number two fireroom. The New Orleans took one Long-Lance torpedo which severed 150 feet (46 m) of her bow. Magnificent damage control work and skillful seamanship kept these ships afloat.

New Orleans class cruisers would be found at every major naval skirmish of World War II in the Pacific despite the fact there were only four units remaining after 1942. They were some of the most used and hardest fought ships on the US Navy during the war. Three ships of the class were included in the top four most decorated ships of the US Navy in World War II. The San Francisco earned^{[citation needed]} 17 Battle Stars and a Presidential Unit Citation, the New Orleans earned^{[citation needed]} 17 Battle Stars, and the Minneapolis earned^{[citation needed]} 17 Battle Stars as well. As a class, they earned a total^{[citation needed]} of 64 Battle Stars and one Presidential Unit Citation.

References

1. ^ Fahey 1941 p. 9

See also

• New Orleans-class cruiser (1896).

External links

• Global Security.org - New Orleans class cruiser
• Global Security.org - New Orleans class cruiser specifications