USS Indianapolis

Lore & Background

In July 1945, Indianapolis completed a top-secret high-speed trip to deliver uranium and other components for 'Little Boy', the first nuclear weapon used in combat, to the Tinian Naval Base, and subsequently departed for the Philippines on training duty. At 0015 on 30 July, the ship was torpedoed by the Imperial Japanese Navy submarine, and sank in 12 minutes. Of 1,195 crewmen aboard, about 300 went down with the ship.

The remaining 890 faced exposure, dehydration, saltwater poisoning, and shark attacks while stranded in the open ocean, with few lifeboats and almost no food or water. The Navy learned of the sinking four days later, when survivors were spotted by the crew of a PV-1 Ventura on routine patrol. A U.S. Navy PBY flying boat crew landed to save those in the water.

Only 316 survived. No U.S. warship sunk at sea has lost more sailors. On 19 August 2017, a search team financed by Microsoft co-founder Paul Allen located the wreckage in the Philippine Sea at a depth of about 18000 ft. On 20 December 2018, the crew of Indianapolis was collectively awarded a Congressional Gold Medal.

Common Misconceptions (Editorial)

Some believe that the USS Indianapolis was sunk because it was on a secret mission to deliver atomic bomb components. However, while it had completed that top-secret delivery, the ship was torpedoed while subsequently en route to the Philippines on routine training duty. Others think that the shark attacks were the primary cause of death; in fact, exposure, dehydration, and saltwater poisoning were also major threats faced by survivors in the open ocean.

Why It Matters (Editorial)

The story of the USS Indianapolis endures as a stark reminder of both the heroism and the operational failures of war. The devastating delay in the Navy’s response—learning of the sinking only four days later—highlights how quickly triumph can turn to tragedy when communication and rescue systems fail. It remains a powerful testament to human endurance and the heavy cost of military service.

Reader's Guide

Indianapolis was the second of two ships in the Portland class, the third class of 'treaty cruisers' constructed by the United States Navy following the Washington Naval Treaty of 1922. Ordered for the U.S. Navy in fiscal year 1930, Indianapolis was originally designated as a light cruiser with hull classification symbol CL-35, reclassified a heavy cruiser with symbol CA-35 on 1 July 1931. The ship had four propeller shafts, four Parsons GT geared turbines, eight White-Forster boilers, 107000 shp giving a design speed of 32.7 kn, and a designed range of 10000 nmi at 15 kn.

She rolled badly until fitted with a bilge keel. Armament included nine 8-inch/55-caliber Mark 9 guns in three triple mounts, eight 5-inch/25-caliber guns, two QF 3-pounder Hotchkiss guns, and in 1945 received twenty-four 40 mm Bofors guns in six quad mounts and nineteen 20 mm Oerlikon cannons. Armor included belt armor between 3.25 in and 5 in, bulkheads between 2 in and 5.75 in, deck armor 2.5 in, barbettes 1.5 in, gun turrets 2.5 in, and conning tower 1.25 in.

The ship had two aircraft catapults amidships and could carry four aircraft. Designed complement was 807, wartime complement 952, which could increase to 1,229 when a fleet flagship. Indianapolis was laid down on 31 March 1930, launched on 7 November 1931, and commissioned on 15 November 1932.

Did You Know?

• Indianapolis was the second ship named for the city of Indianapolis, following a cargo ship of the same name in 1918.