Scuttled in 1951 off of San Francisco, no one has seen this aircraft carrier since--until now. Nautilus expedition have sent down two remotely operated vehicles to explore the wreckage for the first time.
USS Independence (CVL 22) operated in the central and western Pacific from November 1943 through August 1945. It was one of more than 90 vessels assembled as a target fleet for the Bikini Atoll atomic bomb tests in 1946. Damaged by shock waves, heat and radiation, the ship survived the Bikini Atoll tests and, like dozens of other Operation Crossroads ships, returned to the United States.
While moored at San Francisco's Hunters Point Naval Shipyard, USS Independence (CVL-22) was the primary focus of the Navy's studies on decontamination until age and the possibility of its sinking led the Navy to tow the blast-damaged carrier to sea for scuttling on 26 January 1951.
NOAA's interest in this ship is part of a mandated and ongoing two-year mission to locate, map and study historic shipwrecks in Gulf of the Farallones National Marine Sanctuary and nearby waters. The carrier is one of an estimated 300 wrecks in the waters off San Francisco, and the deepest known shipwreck in the sanctuary.
The mission was conducted last month using Echo Ranger, an 18.5-foot-long autonomous underwater vehicle (AUV) provided by The Boeing Company through a cooperative research and development agreement with NOAA's Office of Oceanic and Atmospheric Research. Boeing also partnered with technology company Coda Octopus to integrate its 3D-imaging sonar system, Echoscope, into the AUV.
The USS Independence dive was part of an expedition to explore the Greater Farallones National Marine Sanctuary and Monterey Bay National Marine Sanctuary with partners at the National Oceanic and Atmospheric Administration and the Naval Historical Foundation.
After the war, Independence was one of two aircraft carriers to be positioned at Bikini Atoll for the Operation Crossroads nuclear bomb tests. Two plutonium implosion-type “Fat Boy” bombs were detonated on July 1 and 25, 1946, damaging and irradiating Independence but not sinking her.
Decontamination by acid and sandblasting was conducted in San Francisco following this. Radioactive waste, including the cleaning materials from these decontamination efforts, was sealed in concrete in metal drums and stored in part of the ship for the sinking.
The Nautilus mission to visit Independence this summer carefully considered the potential radiation and contamination risks posed by the site prior to undergoing this expedition. Several factors, including the following, indicate that the risk of contamination should be low.