How do you clean up a wrecked cruise ship?
Damage has to be assessed, the ship's fuel needs to be removed and the boat has to be brought upright again. The process could take months, or even years.
Tue, Jan 17, 2012 at 04:49 PM
TIPPING POINT: Rescuers approach the semi-submerged cruise liner Costa Concordia. (Photo: Andreas Solaro/AFP)
Divers are searching for survivors of the cruise ship Costa Concordia that ran aground off Italy's Tuscan coast and tipped over. But, once the search is called off, what will be done with the half-submerged, $570 million vessel?
Maritime salvage specialists are already on the scene assessing the damage to figure this out. Despite the attention the wreck has gotten in the media, the clean-up process will follow a fairly standard protocol.
"This goes on all the time but you don't hear about it because they aren't as spectacular as this one," Mike Lacey, secretary general of the International Salvage Union, told the BBC. "But there's always a ship in trouble somewhere."
In all, the Costa Concordia mess could take months, and possibly years, to clean up.
First, salvage crews will need to conduct underwater inspections to evaluate the damage of the starboard (submerged) side of the hull. The port-side hull and the rest of the ship that's visible above the waterline have sustained substantial damage. How badly the rocks have gouged the starboard hull will determine how the salvage companies proceed. [Are Cruise Ships a Health Risk?]
Then there's the fuel. The large cruise ship was carrying more than 2,000 tons of diesel fuel when it wrecked. There are no apparent leaks, but officials have deployed anti-spill booms around the ship, in case it shifts on the rocks and one of 17 tanks ruptures. Any spill could cause an ecological nightmare in the area.
A Dutch company called Smit, which specializes in salvage operations, will remove the remaining fuel using a system of pumps and valves that will vacuum the oil out of the ship and into transport tanks. This process will take two to four weeks.
The next step is to get the ship upright. Doing this involves an old-fashioned process called parbuckling, in which barges with huge winches crank the ship into position, bit by bit. Costa Crociere, the ship's parent company, said that inflatable bags could be placed under the ship to help lift it. The air bags would also come in handy to help the vessel float when tug boats need to haul it away.
Once upright, crews will need to clean out the ship. Food in the galleys is probably rotten, and passengers' belongings need to be recovered, though workers suspect that anything below the waterline is probably beyond repair.
Previous shipwrecks have been patched up in order to transport.
"It's possible, with small areas of damage, to prefabricate a [steel] patch and put it into place," said Dawn Gorman, editor of the magazine International Tug & OSV. "It may be the ship isn't salvageable and it isn't possible to right it, patch it up and send it on its way, because fundamental damage has been done."
If this is possible with the Costa Concordia, once it is upright crews will pump out the water, stabilize it and apply patches. But whether this is possible won't be known for weeks, at least.
Once the ship is upright and floating, whether by air bags or on its own, it will likely be towed away by tugboats and be docked elsewhere for full assessment.
It's possible that repairs could make the vessel seaworthy again, but that will be decided by the ship's insurer, who will have to assess the full cost of repairs. Based on initial reports, several experts believe it's more likely that the ship will be declared a total loss and chopped up for scrap.
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