FoundSF

Historical Exhibit

by Stacey Carter

DECOMMISSIONED: The History of Hunters Point Shipyard was curated by Stacey Carter at Building 101 at the HP shipyard, June 5 - August 2, 2025

USS Indianapolis at sea in 1939.

Photo: Wikimedia commons

Secret Cargo, Historic Consequence

As the heavy cruiser Indianapolis (CA-35) was finishing up repairs at Mare Island after being hit by a kamikaze at Okinawa, Captain Charles B. McVay III received orders on July 15, 1945:

“. . . You will sail at high speed to Tinian where your cargo will be taken off by others. You will not be told what the cargo is, but it is to be guarded even after the life of your vessel. If she goes down, save the cargo at all costs, in a lifeboat if necessary. And every day you save on your voyage will cut the length of the war by that much.”

McVay was also warned that he was not to “share the horizon” with any other ship during the voyage, except for a brief stop at Pearl Harbor for fuel.

A unique WWII support function of Hunters Point Shipyard was the loading of components of the atomic weapon “Little Boy” that was eventually used on Hiroshima. This item was loaded on the Indianapolis at 2:00 p.m. on July 15, 1945, and is reported to have contained half of the uranium-235 (U-235) available in the United States, valued at the time at $300 million. A top-secret convoy from Alamogordo, New Mexico, transported the weapon components to Kirtland Air Force Base. From Kirtland, the components were flown to San Francisco’s Hamilton Field. The components were transported to a “safe house” at Hunters Point, where they awaited the USS Indianapolis. The exact location of the “safe house” and the exact time the weapon components arrived have not been determined. Every security precaution was taken, including emptying all drydocks and berths at Hunters Point Shipyard, Marine security guards with automatic weapons, and planes flying surveillance over Hunters Point.

Indianapolis relocated to Hunters Point Shipyard in San Francisco, and the special cargo was brought on board. A large crate about the size of an automobile was craned on board and stowed in the hangar under constant armed Marine guard. The crate actually contained miscellaneous and unclassified gear, along with eight Little Boy bomb pre-assemblies (partly assembled bombs without fissile components). The critical cargo came aboard in two heavy metal cylinders (one a dummy) along with the luggage of two Manhattan Project Army Officers (Major Robert Furman and Captain James Nolan) posing as Army Artillery Officers (and wearing their insignia upside down). The metal canister contained the U-235 projectile that would be fired into the U-235 target in the gun-type Little Boy bomb. This constituted half the uranium-235 in existence. The two officers were put up in the staff flag secretary’s cabin (no flag officer was embarked). Pad-eyes were quickly bolted to the deck of the cabin, and the canisters were chained and locked. Gunnery officers and Gunner’s Mates on Indianapolis quickly figured out that something was fishy when neither Army officer could answer even rudimentary questions about artillery.

At 6:30 a.m. on July 16, 1945, the Indianapolis left Hunters Point Shipyard but was not allowed to leave San Francisco’s harbor until 8:30 a.m., after the first atomic weapon test, “Trinity,” had succeeded in the New Mexico desert. At 0800 local time, 16 July 1945, Indianapolis departed Hunters Point for a record-breaking, high-speed, unescorted transit to Pearl Harbor in 74.5 hours. At about 0800 on July 26, Indianapolis arrived at Tinian and had craned off the cargo into a motor launch and onto a Landing Ship, Tank (LST) in just 20 minutes.

As the ship pulled away from Hunters Point, few knew that this top-secret mission would deliver the components of the first atomic weapon ever used in war—and seal the shipyard’s place in one of the most consequential chapters of world history.

• • •

After delivering its top-secret cargo, the ship subsequently departed for the Philippines on training duty. At 0015 on 30 July, the ship was torpedoed by the Imperial Japanese Navy submarine I-58, 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.

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Decommissioned: Navy Takes Notice 1908

Decommissioned: A Mighty Shipyard 1941-1947

Decommissioned: Hunters Point and the Atomic Turning Point

Decommissioned: The Giant Crane 1947

Decommissioned: After the War 1946-1969

Decommissioned: Naval Radiological Defense Laboratory 1946-1969