Ehime Maru salvage begins next week
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By Mike Gordon
Advertiser Staff Writer
Navy officials are predicting they have an 80 percent chance of successfully moving the Ehime Maru to shallow water later this month.
Richard Ambo The Honolulu Advertiser
Navy Capt. Bert Marsh gives a rundown on how equipment aboard the Rockwater 2 will be used to raise the Ehime Maru so it can be moved to shallower waters.
Richard Ambo The Honolulu Advertiser
The Ehime Maru lies on the ocean floor in 2,000 feet of water. The water pressure there is so great, it crushed the steel mast of the vessel as it sank.
The Navy wants to move the ship to a depth of 115 feet so divers can safely recover as many bodies as possible and return them to Japan.
Lifting the Ehime Maru from the ocean floor will be up to the crew of Rockwater 2, a red and orange civilian ship that costs about $6.6 million to use. The entire project is expected to cost $40 million and last until October.
Rockwater 2 is scheduled to leave Honolulu Harbor by Tuesday and head for a featureless patch of ocean above the Ehime Maru, nine miles south of Diamond Head.
It is there that the USS Greeneville carved a gash in the Ehime Maru while performing a surfacing drill for 16 civilian guests. Cmdr. Scott Waddle, then-skipper of the submarine, rushed his periscope inspection of the surface before putting his 6,900-ton nuclear submarine on a collision course with the Ehime Maru, a ship used to teach Japanese high school students how to fish.
Four of the missing were 17-year-old boys.
It will take about two weeks for Rockwater 2 to rig a cradle beneath the Ehime Maru, but the real challenge will come when the winches take up the slack on four lengths of 4-inch-thick cable, said Rear Adm. William R. Klemm, deputy chief of staff for maintenance of the U.S. Pacific Fleet.
"I think that point is perhaps the single point where the risk is greatest," Klemm said yesterday. "I have very high confidence that we will be able to get to the point where we can lift the ship. I think the much greater risk comes at the point where we raise the ship and have to move it."
Owned by Halliburton Co., a Texas-based construction and engineering company, the 5,991-ton Rockwater 2 will use oil industry technology in ways never attempted before.
Remotely operated vehicles the size of cars will do the work of divers during the deep-water rigging.
"We are well beyond the capacity of divers to work and so it all has to be done by remote control," Klemm said. "Had this happened 15 years ago, we wouldn't have been able to do anything because the technology didn't exist."
Coiled tubing normally used to bore into wells will instead be bent so a jet of water can carve pathways beneath the Ehime Maru, said Capt. Bert Marsh, supervisor for salvage and diving at the Naval Sea Systems Command.
Also, the pumping equipment that can send water through the tubes at 3,500 pounds per square inch is normally on the surface, Marsh said. For this mission, it will be lowered to the seabed near the Ehime Maru's present location.
Many of the items used on the project, including the two 150-foot long lifting plates, were custom made for the job, Marsh said.
Special winches that span the width of the Rockwater 2 deck had to be welded in place. They will hold the four lengths of cable that raise the the 830-ton Ehime Maru.
With the damaged fishing vessel suspended just 90 feet off the bottom, Rockwater 2 will sail slowly toward a spot a mile south of the reef runway.
Marsh has worked on the project since February. He is anxious to start, he said.
"It's been a long process, a difficult process," he said. "There were a lot of questions that had to be answered."
The bulk of the move a distance of about 12.5 nautical miles will occur in in deep water. It is only on the last day of the move, expected to last three days, that Rockwater 2 will have to raise the Ehime Maru about 1,500 feet.
Klemm cautioned that the mission could fail at any point, stressing diver safety over the recovery of remains. If the ship broke en route to its new location, it is unlikely the Navy could recover anything, Klemm said.
"If the plan fails because a piece of equipment fails, then Plan B is we have back-up equipment," he said. "If the structural integrity (of the Ehime Maru) fails, the chances are good we will have to give it up."
He said divers are prepared to force their way through jammed passageways and watertight doors. They have an idea where they will find missing people.
"Realistically, given the locations of some of them, they would have been en route to exterior locations and may very well have succeeded in getting out of the ship, but did not survive the sinking," Klemm said.
That part of the mission could ultimately prove to be tougher than any technological challenge, Klemm said.
"Divers are going to recover remains of seamen," he said. "That is a very traumatic experience."