New Orleans - class cruiser The " New Orleans " class cruisers were a class of seven heavy cruiser s built for the United States Navy ( USN ) in the 1930s . Originally called the " Astoria " - class cruiser , the class was renamed after " Astoria " was sunk and the surviving ships of the class underwent substantial reconstruction . 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 " , the single ship of the class to spend most of World War II 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 , which is why there were three distinct designs within this class . This class was the direct ancestor for all subsequent USN gun cruisers . From them came the , , , and the 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 was the lead ship of this class , but , and , laid down as " Portland " - class 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 all lost in 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 . The four survivors were decommissioned shortly after the war ended , and scrapped in 1959 – 1961 . Armor . The seven ships of the " New Orleans " class were the penultimate US Navy cruisers , with the exception of the , 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 , the and the 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 in of armor on all ships except the , 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 ( The 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 increase in protection was not effective , as the Savo Island battle showed . " Astoria " , " Vincennes " , and " Quincy " were quickly sunk by shells and torpedoes from attacking Japanese ships , their armor being easily pierced . Armament . The main armament on the class centered on nine 8in / 55 caliber Mark 14 guns ( Mark 9 guns until replaced in WW2 ) , 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 with a muzzle velocity of . The armor piercing round weighed and could penetrate five inches of armor plating at . 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 and performance . Outwardly , the " New Orleans " ships had a distinctive appearance and were considered very good looking vessels , though the 1942 - 43 refits of the surviving ships changed the appearance substantially . The forward superstructure had the bridge wings cut back , and all of the large size windows were plated in with just a few port holes taking their place . The open bridge above the wheel house was enlarged by 100 percent by extending it forward . In addition several gun tubs were created for the 40mm Bofors mounts both around the main mast , and aft . 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 for the four Westinghouse gearing steam turbines . The turbines were shafted to four screws , giving this class a rated speed of . The cruisers ' range – using of bunker oil – was approximately at or at . 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 . 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 – 9 Aug 1942 . Although three of their number were lost , the ships proved to be well designed . The tragical 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 " and the " New Orleans " took heavy damage and losses from Long - Lance torpedo es . Magnificent damage control work and skillful seamanship kept these ships afloat to continue to fight through the end of the war . " New Orleans " class cruisers were found at every major naval skirmish of World War II in the Pacific despite the fact there were only four of the seven units remaining after the first year of war . They were some of the most used and hardest fought ships of the US Navy during the war . Three ships of this class were among the highest decorated US ships of the Second World War . The " San Francisco " earned 17 Battle Stars and a Presidential Unit Citation , the " New Orleans " earned 17 Battle Stars , and the " Minneapolis " earned 17 Battle Stars as well . As a class , they earned a total of 64 Battle Stars and one Presidential Unit Citation .