Navy forced to Plan B in Ehime Maru salvage
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Advertiser graphic referred to by Marsh. |
By Mike Gordon
Advertiser Staff Writer
An effort to drill beneath the Ehime Maru has failed, prompting Navy salvage experts to adopt a backup plan in their ambitious attempt to raise the wreck from 2,000 feet of water.
Lifting the Ehime Maru by a single point was not a first choice because engineers were concerned that the hull, which was severely damaged when it was struck by a submarine in February, would break apart.
The Navy believes the hull of the Ehime Maru is stronger than original estimates, said Capt. Bert Marsh, the Navy's director of ocean engineering and supervisor of salvage and diving.
The drilling device, a coiled tube that uses a high-pressure jet of water to cut through sediment, was supposed to create a curved path for the cable, called "messenger wire." Although the device cut easily through the ocean floor as it dived beneath the Ehime Maru, it never came up on the other side, Marsh said.
"We are shifting gears, slightly, and we are going to use a well-proven method to lift her so we can pass messenger wires beneath the hull," Marsh said.
But there are no guarantees with this plan, either.
"The principal risk is you tend to stress the hull more than with the drilling," Marsh said. "In this case, we will lift her a very small amount. We only need to snake a wire through."
He could not say exactly how high the Ehime Maru would be lifted or for how long, but did say the rudder area is one of the strongest points of the ship.
"We will have a very short time frame in which we can lift the stern," he said. "We want to keep it as short as possible. Hours."
The Navy wants to move the Japanese fisheries training vessel to 115 feet of water, but nothing this heavy has ever been lifted from this depth.
The Ehime Maru sank Feb. 9 after colliding with the USS Greeneville about nine miles south of Diamond Head. Five crew members and four high school students went down with the vessel.
Their bodies are thought to be trapped inside the hull, and the Navy has promised their families that it would do everything possible to recover them. If the vessel can be moved to a shallow water site one mile south of the reef runway, Navy divers plan to enter the hull and search for bodies.
In Japan, the widow of one of the lost crewmen said she still hopes for the best.
"I am wondering if my husband's body will be inside of the ship, so I am hopeful that the salvaging will be successful," said Chihoko Nishida, widow of Hiroshi Nishida. "I can't do anything but wait. I don't want them to hurry."
If remains come out of the ship during any of the lifting procedures, the Navy will recover them with remotely operated vehicles, Marsh said.
The Navy still believes it has an 80 percent chance of success, Marsh said. He said the backup plan should still allow the Navy to move the ship within a 30-day window that ends in mid-September.
He said a spare lifting plate would be loaded onto Rockwater 2, the civilian vessel contracted to make the lift. Rockwater 2 returned to Honolulu Harbor yesterday morning and will probably leave for the deep-water site in a day or two.
The task of rigging a lifting plate beneath the stern of the Ehime Maru is relatively easier because that portion of the ship is exposed. Technicians aboard Rockwater 2 will use remotely operated vehicles, tethered to the surface ship, to accomplish the job.
While the Navy is confident it will succeed, Marsh likened the task to standing atop a pair of Empire State Buildings and casting a fishing line to the sidewalk below, aiming for a 6-inch square.
"And oh, by the way, the building is moving," Marsh said.
Using the remote vehicles to connect the heavy rigging is no easier. It's like wearing a set of snow mittens and then trying to thread a needle with one eye closed, Marsh added.
Soon after Rockwater 2 first arrived over the Ehime Maru two weeks ago, salvage experts were able to spend more time viewing the wreck through video cameras on the remotely operated vehicles.
"We have been able to see there is no significant sign of buckling or cracks in the bow," said Cmdr. Dave Wray, a Navy spokesman for the recovery operation. "What we have seen makes us more comfortable."
Interpreter Toshi Erikson contributed to this report.