A U.S. Navy-led salvage team has successfully removed 229,000 gallons of oil from the sunken World War II vessel ex-Prinz Eugen located in the Kwajalein Atoll in the Marshall Islands.
The project, led by the Navy’s Supervisor of Salvage and Diving (SUPSALV), which is part of the Naval Sea Systems Command, and sponsored by the U.S. Army Space and Missile Defense Command /Army Forces Strategic Command. It was led by Stephanie Bocek of SUPSALV.
The success of the oil removal comes after two years of intensive research and planning to prepare for the unprecedented removal of oil from up to 173 tanks from the from the World War II German heavy cruiser.
Prior to removal of oil, SUPSALV’s Emergency Ship Salvage Material oil spill response team worked to deploy the equipment, tools and consumables to support the operation. The load-out included “hot tap” oil extraction systems, submersible pumping systems, oil spill response resources, tank close-out and patching supplies, and other diver tools.
In order to collect the recovered oil, the salvage team chartered the commercial oil tanker Humber to store the oil and transport it for disposal or recycling at the end of the operation.
During the operation, the Humber, along with Military Sealift Command’s USNS Salvor, were positioned directly above the ex-Prinz Eugen in order to effectively conduct the oil removal.
“This task was challenging because of the close proximity of the wreck to the neighboring shoreline which would not allow the ships to drop the shoreward anchors due to shallow depth,” according to Naval Sea Systems Command of the project. “Ultimately, SUPSALV arranged for use of the U.S. Army Garrison – Kwajalein Atoll’s harbor tug Mystic to collect the anchors at the pier and drop them in place this allowed the ship to successful finalize their four-point moor over ex-Prinz Eugen.”
Each of the wreck’s accessible, oil-filled tank was hot tapped, pumped free of recoverable oil, and sealed with a permanent, tamper-proof dome assembly to prevent any more leakage of residual oil left in the tank. “These actions ensured that the wreck, a popular dive site, is safe for continued recreational diving and the Atoll is safe from the risk of significant oil spill from ex-Prinz Eugen,” NAVSEA said.
Former German Heavy Cruiser Prinz Eugen
After WWII, the Prinz Eugen, a former heavy cruiser for Nazi Germany’s Kriegsmarinewas, was transferred to the U. S. Navy as a war prize from the British Royal Navy. In 1946, it was loaded with oil and cargo and used to test its survivability during the famous Operation Crossroads atomic bomb tests at Bikini Atoll. Although it survived the initial blast, the ship sank a few months later with 2,767 metric tons of oil still in its tanks.
A U.S. Navy report on the oil spill risk conducted in 1974 recommended that the oil be removed within 30 years, but the project never materialized and ownership of the wreckage was eventually transferred to the Republic of Marshall Islands in 1986.
“This project was an incredible opportunity to showcase the U.S. Navy Salvage community’s capabilities. SUPSALV had prior experience with sunken vessel oil removal on ex-USS Chehalis and USS Missessinewa so we were well positioned to lead this project,” said Capt. Keith Lehnhardt, Supervisor of Salvage and Diving. “This also serves as an example of exceptional partnership for future oil spill responses, salvage operations, and other emergencies.”