Portland - class cruiser The " Portland " class of heavy cruiser s was a class of ships designed and constructed by the United States Navy in 1930 . The two ships of the class , and saw extensive service during the Pacific War in World War II . Designed as a modification over the previous " Northampton " class cruiser , the " Portland " class displaced nearly and featured heavier armor and armament than previous cruisers . Featuring 8 " / 55 caliber gun s intended for shore bombardment and designed to function as fleet flagships , the " Portland " class were intended to fix problems with armament and armor that had been a weakness of preceding U . S . cruisers . These designs were carried over to the following " New Orleans " class , of which several " Portland " cruisers were converted to mid - construction . " Portland " served in a large number of engagements including the Battle of Coral Sea , the Battle of Midway and the Battle of Guadalcanal , where she was severely damaged but nonetheless able to return to service . She later fought in the Battle of Leyte Gulf and the Battle of Okinawa . " Indianapolis " served as a fleet flagship for much of the war and fought in the Battle of Philippine Sea and the Battle of Iwo Jima . On 30 July 1945 , after transporting components for the nuclear weapons Little Boy and Fat Man from the United States , she was torpedoed by the Japanese submarine " I - 58 " . Due to a series of errors and miscommunications her loss was not discovered for several days , and only 316 of her 1 , 116 crew survived . Background . The " Portland " class was the third class of heavy cruiser to be constructed by the United States Navy following the Washington Naval Treaty of 1922 . The first " treaty cruisers " were the two of the s ordered in 1926 , which emphasized armament and speed at the expense of protection . These ships were followed by the six vessels of the ordered in 1927 which were more heavily - armed , and introduced the configuration of three triple turrets which would become standard on U . S . Navy heavy cruisers . The " Portland " class was a modification of both the " Pensacola " and " Northampton " designs . Ordered for the U . S . Navy in fiscal year 1930 , the " Portland " class was originally designated as a light cruiser , and given the hull classification symbol CL , being re - designated a heavy cruiser with the symbol CA on 1 July 1931 , due to their armament , in accordance with the London Naval Treaty . Originally , eight cruisers were envisioned as modified as modified " Northampton " class vessels , but eventually two of these became the " Portland " class , with the remaining six eventually being further modified into the succeeding . Design . As built , the " Portland " class cruisers were to be in length overall , and long at the waterline . abeam , and with a draft of , and maximum . They were designed for a standard displacement of , and a full - load displacement of . However , neither completed ship reached this weight , displacing and , respectively . The ships featured two distinctive raked funnels , a tripod foremast , and a small tower and pole mast aft . In 1943 , light tripods were added forward of the second funnel on each ship , and a prominent Naval director was installed aft . The ships were equipped with four propeller shafts and four Parsons GT geared turbine s and eight Yarrow boilers . The power plant of the ships generated and the ships had a design speed of The ships were designed for a range of at . Both completed ships rolled badly until fitted with bilge keels . The cruisers were armed with a main battery of nine Mark 9 8 " / 55 caliber gun s arrayed in three triple mounts , a superfiring pair fore and one aft . For anti - aircraft defense , they were armed with eight 5 " / 25 caliber gun s as well as two QF 3 pounder Hotchkiss guns . In 1945 , the anti - aircraft defenses of both ships were upgraded , with each receiving twenty four Bofors 40 mm guns . On these were arranged in four quad mounts and four twin mounts , and on they were arrayed in six quad mounts . Both ships were also upgraded with twelve Oerlikon 20 mm cannon s . No torpedo tubes were fitted on either ship of the class . The ships were outfitted with Mk . 8 rangekeeper s and Mk . 27 directors which also housed auxiliary Mk . VII rangekeepers . The " Portland " class was originally designed with of deck protection and 1 inch ( 25 mm ) of side protection , but during construction they were substantially up - armored . The ships were completed with belt armor thick over the magazines and elsewhere . Armored bulkhead s were between and , deck armor was , the barbette s were , the gunhouse s were , and the conning tower was . Additionally , the " Portland " class cruisers were designed with space to be outfitted as fleet flagship s , with space for an Admiral and his staff to operate . The class also featured an aircraft catapult amidships . They could carry four aircraft . The total crew complement varied , with a regular designed crew complement of 807 , a wartime complement of 952 , which could increase to 1 , 229 when the cruiser was operating as a fleet flagship . Comparison with previous cruiser designs . The " Portland " class was generally longer than the " Northampton " class by about and featured a revised bow shape . They were otherwise generally similar to the " Northampton " class , with an extended forecastle to improve sea - keeping abilities . Their masts were reduced as compared to the " Northampton " class in order to reduce top weight . When completed , the " Pensacola " class displaced less than expected , at , which was less than expected , and were found to be greatly deficient in their protection . For the following " Northampton " class , the armor protection was increased to with of armor along the main belt . Still , these ships only displaced between and While the " Portland " class cruisers were more heavily armored than the preceding classes , this problem was found to be so significant that in fiscal year 1929 , an entirely different design was formulated for a new class of cruisers , the " New Orleans " class . Several of the " Portland " hulls were then converted to " New Orleans " hulls during construction . The " Portland " class were also designed with more advanced armament in mind . Their main guns were the first to be specially designed to fire long - point projectiles with a streamlined shape , which increased the guns ' range when compared with older cruiser guns . Such projectiles were in use by ships of the Imperial Japanese Navy , which until that point out - ranged U . S . cruisers with their firepower . The " New Orleans " class was designed with these lessons in mind , intended to create a better balance between protection , armament and speed . Construction . Five ships were ordered in fiscal year 1930 , to be constructed by three builders . In 1931 , CA - 32 , CA - 34 , and CA - 36 , all ordered with Westinghouse machinery , were converted to the " New Orleans " class . " Portland " was laid down by Bethlehem Steel at Quincy Shipyard on 17 February 1930 , and " Indianapolis " was laid down by New York Shipbuilding Corporation on 31 March 1930 . The hull and machinery of both ships was provided by their respective builders . " Indianapolis " was launched first , on 7 November 1931 and commissioned on 15 November 1932 . " Portland " was launched on 21 May 1932 and commissioned on 23 February 1933 . Ships in class . USS " Portland " ( CA - 33 ) . " Portland " was the first ship on the scene when the airship went down in 1933 , and coordinated efforts to retrieve survivors . She conducted a number of fleet maneuvers and goodwill missions throughout the Pacific Ocean . After the start of World War II , " Portland " took part in the Battle of Coral Sea , there rescuing 722 survivors from the sunk aircraft carrier . She then fought at the Battle of Midway , the Battle of the Eastern Solomons , and in the Battle of the Santa Cruz Islands , where she was hit by three dud air - launched torpedoes . She then supported U . S . Marine landings during the Battle of Guadalcanal . During the naval battle there in late 1942 , she was struck and severely damaged by a torpedo from a Japanese destroyer , a hit which required interim repairs in Australia followed by extensive repairs at Mare Island Navy Yard . In spite of this damage , she was still able to inflict damage on the Japanese battleship " Hiei " . Returning to the war , she bombarded Kiska as part of the Aleutian Islands campaign , played a supporting role in the Gilbert and Marshall Islands campaign , covered landings during the New Guinea campaign , and Pelelieu . She then participated in the Battle of Leyte Gulf , covered landings in the Philippines , and supported the Battle of Okinawa . At the end of the war she was decommissioned and remained in the United States Reserve Fleet until 1959 , when she was broken up for scrap . USS " Indianapolis " ( CA - 35 ) . " Indianapolis " served as flagship of Scouting Force 1 during World War II , and saw action in a number of campaigns in the Pacific theater . She supported the Gilbert and Marshall island campaigns as well as operations off the Caroline Islands . Later in the war she fought in the Battle of Philippine Sea and later the Battle of Iwo Jima and participating in the Battle of Okinawa . In mid - 1945 , she sailed from the United States to Tinian Island carrying components of Little Boy and Fat Man , the two nuclear weapons which would later be used to bomb Hiroshima and Nagasaki . Sailing for Leyte unescorted under Captain Charles B . McVay III , she was torpedoed by Japanese submarine " I - 58 " on 30 July 1945 , sinking in just 12 minutes . An estimated 800 of her 1 , 119 crew survived the initial sinking , but her SOS signal was not heard , and due to a series of errors and misunderstandings , her loss was not discovered until 2 August when her crew was spotted by reconnaissance plane . Only 320 men were recovered following the sinking , of whom 316 survived . McVay survived and faced a court martial and reprimand but retired in 1949 as rear - admiral , committing suicide in 1968 .