As early as May 1942 the Navy indicated that it wanted to salvage the battleship USS Oklahoma, according to the writings of retired Vice Adm. Homer N. Wallin, who was charged with the fleet salvage as a Navy captain.

“The righting of a ship weighing about 35,000 tons was no easy task,” Wallin said in 1968. The Oklahoma had received nine torpedo hits on the port side.

The battleship capsized roughly 20 minutes after the attack, trapping more than 400 men inside. Only 32 were rescued by frantic shipyard crews cutting through the bottom with torches and pneumatic cutters, according to the National Park Service.

Twenty-one electric winches were anchored in concrete foundations on Ford Island, with 3-inch cables passing over 40-foot wooden struts on the bottom of the overturned ship to increase leverage.

Navy crews hoped the Oklahoma would roll and not slide. The bow section rested in soupy mud, and to prevent sliding, about 2,200 tons of coral soil was deposited near the bow, Wallin said.

The ship rolled as desired, and was right side up by June 16, 1943.

To make the torpedo-damaged hull watertight, one patch alone was 130 feet long and 57 feet high. More than 1,000 tons of tremie underwater concrete was poured to seal the patches.

The ship was pumped out, and the remains of sailors and Marines were recovered, the National Park Service said. The battleship entered dry dock on Dec. 28, 1943. Following its decommissioning in September 1944, the guns and superstructure were removed, the Park Service said.

The Oklahoma began its final cruise in the spring of 1947 under tow to San Francisco, but began listing to port. The tow lines were cut, and the once mighty battleship sank beneath the waves northeast of Hawaii.