Hawaii-based Navy divers from Mobile Diving Salvage Unit 1 recently completed the removal of 250,000 gallons of fuel oil from a captured World War II German cruiser that survived two atomic tests in 1946 but capsized and sank later that year at Kwajalein Atoll.
Twenty divers from the unit worked from the USNS Salvor to recover oil from the 697-foot Nazi warship, which lies partially exposed 200 yards offshore from Enubuj Island and just a few miles from the strategically important Kwajalein Island, the largest in the group.
The tiny Army-run island in the Marshall Islands is a U.S. outpost in the South Pacific for space surveillance and object identification, NASA programs and ballistic missile development and testing. It also has a 6,600-foot runway.
“These (oil) recovery efforts will ensure mission capability of the U.S. Army Space and Missile Defense Command/Army Forces Strategic Command’s Ronald Reagan Ballistic Missile Defense Test Site on Kwajalein while protecting the sensitive ecosystem within the atoll,” the U.S. military said in a news release.
The removal effort began Sept. 1 and was completed Oct. 15 using the Salvor and commercial tanker Humber to transport the removed oil.
After placing nine mooring lines to hold both vessels over the wreck, the dive team drilled holes into each fuel tank using a process called “hot tapping,” allowing valves to be installed without fuel leakage, the Navy said.
In October 1943 the Prinz Eugen became the flagship for German forces in the Baltic Sea. The cruiser was surrendered to the British in Denmark in 1945, became U.S. property, and in early 1946 steamed to Boston and then through the Panama Canal to the Pacific for atomic bomb tests at Bikini Atoll.
Operation Crossroads involved two explosions, Able and Baker, to determine the effects of atomic bombing on naval warships. A fleet of 90 vessels was assembled as a target, according to the Atomic Heritage Foundation.
The first test, Able, on July 1, 1946, involved a 23-kiloton device dropped from a B-29 bomber which detonated at 520 feet — missing its target by nearly half a mile but sinking five ships, the foundation said.
Baker was conducted July 25, testing another 23- kiloton device, this time detonated 90 feet underwater.
“The spray generated by the blast coated the surrounding ships with radioactivity and the target fleet remained too radiologically contaminated for several weeks for more than brief on-board activities,” the Atomic Heritage Foundation said.
The damaged Prinz Eugen was towed to Kwajalein, where the ship began to list significantly Dec. 21 and capsized a day later on a coral reef, according to the Navy.
After gaining military control of the Marshall Islands from Japan in 1944, the United States assumed administrative control, the U.S. State Department said.
The Marshall Islands signed a Compact of Free Association with the United States in 1983 and gained independence in 1986. That relationship of free association continues.
In 1994 the Navy recommended fuel removal within 30 years, according to the U.S. Fish and Wildlife Service. In 2010 the Republic of the Marshall Islands requested U.S. technical and financial support for the effort, the Navy said.
Kwajalein is increasingly important as China makes inroads in the South Pacific, and the U.S. Indo-Pacific Command in 2016 worked with the Navy to plan for the fuel removal when funding became available.
“Our team’s hard work over the last two years preparing for this project and assembling the right combination of equipment and technical expertise enabled our success in this very important mission to protect the pristine waters of Kwajalein Atoll from the risk of catastrophic oil release,” Stephanie Bocek, a project manager, said in a Navy release.