The New Orleans-class cruisers were a class of seven heavy cruisers built for the United States Navy (USN) in the 1930s.
These ships participated in the heaviest surface battles of the Pacific War. Astoria, Quincy, and Vincennes were all sunk in the Battle of Savo Island, and three others were heavily damaged in subsequent battles in the Guadalcanal campaign. Only Tuscaloosa, which spent most of the war in the Atlantic, got through the war without being damaged. Collectively, ships of the class earned 64 battle stars. The four surviving ships were laid up immediately after the end of the war, and sold for scrap in 1959.
Design
The New Orleans-class design was a test bed for innovations in cruiser design, and there were three distinct designs within the class.
Originally called the Astoria class, the class was renamed after USS Astoria was sunk and the surviving ships of the class underwent substantial reconstruction. 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 , , , and 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 was the lead ship of this class, but , and , laid down as ships, were reordered to the Tuscaloosa design in 1930; and were being built in civilian rather than Navy yards and were completed as originally designed.
Three ships of the class (Astoria, Quincy, and Vincennes) were lost in the Battle of Savo Island in 1942. Immediately following the Guadalcanal campaign the remaining ships of the class went through major overhauls to lessen top-heaviness caused by new electrical and radar systems and anti-aircraft weaponry which had been 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. The four survivors were decommissioned shortly after the war ended, and scrapped in 1959–1961.
Armor
The New Orleans class was the last series of US cruisers completed to the limitations of the Washington Naval Treaty of 1922. As completed, the single ship Wichita class (and subsequent heavy cruisers) exceeded the 10,000-ton standard.
Design of these ships began in early 1929, based on the three preceding classes: The , the and the Portland classes. 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 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 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 . The machinery bulkheads were given and the deck armor was strengthened to . 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, on the sides and on the roof. The barbettes were protected with 5 inches of armor on all ships except , whose barbettes were fitted with of armor.
Magazine protection was increased to . 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 ( 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.