Raising the Costa Concordia, the biggest sea salvage operation ever (+video)
As its captain waits to hear whether he will face charges after capsizing, the Costa Concordia still lies off Giglio Island. Now, hundreds of workers are preparing to float the wreckage.
Giglio Island, Italy
It has lain like a great white whale in the crystal clear waters off the Italian island of Giglio for nine months, but a new, crucial phase to remove the capsized Costa Concordia cruise ship is about to swing into action.
A multinational team of more than 450 specialists, including 60 scuba divers, has almost completed the stabilization of the 950-foot long vessel, anchoring it to the rocky sea shore with four massive cables looped beneath its belly.
Now they are about to start the Herculean task of preparing to raise the cruise ship, which sank on the night of Jan. 13 after its captain, Francesco Schettino, allegedly misjudged a “sail-past” maneuver and rammed it into a rocky outcrop about 150 yards off the island.
A pre-trial hearing in Grosseto, the nearest city on the Italian mainland, is expected to decided whether to send him to trial on charges of manslaughter and abandoning ship in violation of maritime law.
The 4,200 passengers and crew had to scramble for safety in the darkness, clambering into lifeboats and even leaping into the sea. Thirty-two people lost their lives.
The Concordia has been wedged on rocks and semi-submerged just a few yards from the coast of Giglio ever since.
The removal of the cruise liner – essentially a floating hotel and shopping mall – will be the biggest operation of its kind ever attempted and is expected to cost at least $400 million. At 114,500 tons, it is twice as heavy as the Titanic, which sank after hitting an iceberg in the North Atlantic in 1912. The task of lifting it is so epic that it is expected to take eight months, maybe longer.
It was initially hoped that the Concordia could be refloated and towed away to be dismantled in January. But Capt. Nick Sloane, a South African who is in charge of the operation to refloat the wreck, said there was so much work still to do that June was more likely.
If the coming winter is severe, with rough seas and high winds, the schedule could slip further, affecting Giglio’s lucrative summer tourist season.
“The initial timeline has been blown out of the water,” Captain Sloane said aboard a British-crewed tug boat, which provided an up-close view of the rusted, stricken cruise ship.
'No small feat'
The granite rock on which the Concordia rests was proving very hard to drill, said Sloane. His men have started drilling 26 holes in the rock, in which to place massive, 6-foot-wide pillars which will support six platforms covering an area the size of a football field. The platforms will support the ship as it is slowly hauled upright.
The ship will be refloated with the aid of 15 enormous, hollow compartments – known as "sponsons" – which will be bolted onto its port, seaward-facing side.
“The biggest are 32 meters high, which is the height of an 11-story building,” said Sloane. “They weigh 500 tons, and to get them lined up exactly so that we can weld them on is no small feat."
"This is an unprecedented operation. It’s the biggest ship recovery operation ever, by quite some margin.”
Cables will be fixed to the sponsons and then attached to the artificial platform beneath the ship.
The cables will be slowly tightened along the length of the ship in a technique known as “parbuckling,” rolling the ship seaward into an upright position. The sponsons will also be filled with sea water, further helping to drag the liner upright.
When it is upright, another 15 sponsons will then be welded to the starboard, landward side of the ship, balancing the port sponsons.
Finally, the seawater will be pumped out of the compartments, giving the ship buoyancy and enabling it to float free of the underwater platform. (Canadian Business magazine offers a graphic explaining the procedure.)
In addition to the platforms, the bowl-shaped space underneath the ship will be filled in with sacks holding nearly 18,000 tons of cement, which will be removed once the Concordia is towed away.
It will be taken to an as yet unspecified Italian port, where it is likely to be broken up for scrap metal.
“The concept is simple, but there are a few challenges along the way,” said Sloane, with some understatement.
“The forces involved in lifting the ship upright are huge. Internal structural components could fail. If she starts twisting, we have to correct that immediately. If we have a mild winter, that will be great. But it’s unlikely.”
The removal operation is being conducted jointly by American salvage firm Titan and Italian offshore rig company Micoperi, which were commissioned to do the job by Costa Cruises, the Italian owners of the Concordia.
Titan has extensive experience with salvaging stricken container ships around the world, including the recovery of a beached container ship loaded with 5,000 vehicles in the North Pacific and an oil rig that was adrift off Tristan da Cunha in the South Atlantic, one of the most remote inhabited islands in the world.
“For an operation of this size, there is always a worry that something could go wrong,” said Franco Porcellacchia, vice president of Carnival Corporation, the US company that owns Costa Cruises. “But we have some of the best technicians in the world working on this, so we are confident it will work.”
The removal of heavy oil and diesel from the ship’s fuel tanks earlier this year assuaged fears of an environmental disaster.
Still, experts are going to unusual lengths to protect marine animals and plant life around the ship, includes sponges and coral.
The huge shadow cast by the Concordia has killed a large swath of sea grass beneath it, endangering about 200 giant clams, a species commonly known as the “noble pen shell,” which can reach 3 feet in length.
Marine biologists in diving gear have painstakingly transplanted the molluscs to a bay along the coast where the sea grass is still thriving.
Giglio is part of the Tuscan archipelago of islands, a marine conservation area with a large population of whales and dolphins, and the experts have devised an ingenious technique to protect the animals from the noise of the heavy drilling going on around the ship.
When drilling starts, two underwater tubes pump compressed air into the water, creating a “a wall of bubbles.”
“It absorbs much of the noise and reduces the effect on cetaceans,” said Giandomenico Ardizzone, a professor of marine ecology at La Sapienza University in Rome. “We are trying to limit the environmental impact of this disaster as much as we possibly can.”