In what is being called the largest salvage operation of its kind in history, two salvage companies have been hired to refloat and tow away Costa Concordia, the huge luxury cruise ship that struck a rock and foundered near an Italian island in January.
Thirty people died and two are still missing as a result of the disaster. The ship, carrying 4,229 passengers and crew, tore a hole in its hull when its captain took the vessel to within 500 feet of Giglio Island on Jan. 13. The ship, listing sharply to starboard, came to rest on the bottom near the island, with its upper deck and much of its port side above the surface.
In late April, Titan Salvage, owned by Crowley Maritime Corp., and the Italian marine contractor Micoperi were awarded the contract to remove the 952-foot, 114,147-gross-ton ship in one piece. The contract is designed to minimize the environmental impact of the wreck and to protect the tourism economy of the nearby island.
The salvage operation will be the largest ship removal, by weight, in history, Titan Vice President Rich Habib said at a May 18 press conference in Rome, where the salvage plan was unveiled.
The project is expected to cost about $300 million. Titan-Micoperi hope to have the vessel refloated and towed to an Italian port by Jan. 31, 2013.
The salvage plan entails the use of caissons, cranes and pulling machines to roll the wrecked vessel upright onto specially constructed platforms underneath the ship. Water will be drained from the caissons, which will be filled with air to refloat the vessel. The work to remove the ship began in May.
The massive scope of the project is one of the factors that make the job so difficult. “The most challenging aspect of this project that I see is the sheer magnitude of the vessel,” said David DeVilbiss, vice president of marine casualty and emergency response services at Global Diving & Salvage Inc., in Seattle.
Another factor complicating the task is that the vessel is in a tourist area, close to shore.
“You are definitely under a microscope,” he said.
All the heavy fuel, diesel oil and sludge were removed from the wreck by March 24 by the Dutch salvage company SMIT.
Titan and Micoperi will start by measuring water quality and surveying marine life before the project begins to establish a base line so the site can be restored to its original state. The structural integrity of the ship will also be checked.
Buck Banks, spokesman for the North American office of shipowner Costa Crociere, said the inspection of the wreck site will be done by July 31 and a safety survey of the wreck completed by Aug. 31. Titan-Micoperi will then install holdback pilings on the ocean floor on the ship’s starboard side, according to a video released May 18 by the two salvage companies.
Tieback cables from the pilings will be attached to the ship’s hull to keep it from sliding into the ocean. Next, steel plate slings will be installed under the hull and connected to more tieback cables, according to the video. Large grout bags filled with sand and cement will be laid underneath the hull to provide more hull support, to help keep the steel plates in place and to help the ship pivot.
Several platforms measuring about 130 by 130 feet each will be built and anchored to the ocean floor by restraining poles to support the ship when it is rolled upright. The poles will be drilled into the sea floor using a technique that will leave no debris behind after the poles have been removed, according to the video. Watertight caissons will be welded to the port side. They will come with the pulling machines already installed. The machines will be connected to pulling points on the platform.
Using two cranes and the pulling machines, the ship will be pulled upright, inch by inch, aided by the caissons, which will be filled with water. Holdbacks on the starboard side will keep the ship from sliding along the ocean floor.
Once the ship is righted, caissons will be welded to the starboard side. The water in the caissons will be purified to prevent pollution. Then the caissons will be filled with air, lifting the ship off the platforms.
Costa Concordia will be towed to an Italian port yet to be determined, where it is likely to be scrapped.
Representatives of Titan and Micoperi said they could not comment on the project for this article.
According to Joseph Farrell, president and CEO of Resolve Marine Group, the key point will come when the vessel is rolled upright. Resolve, which is based in Fort Lauderdale, Fla., and five other American companies were among the 10 finalists for the salvage contract.
Farrell noted that the vessel is lying on two humps, fore and aft. “The rest of it is not very well supported,” Farrell said. “When they make that axis of the turn, from her beam ends to a vertical position, there is a potential to crush the hull.”
Farrell said the grout bags Titan-Micoperi plans to lay down will help to create a more level surface on the sea floor between the bow and stern.
This way “you’re not putting extreme loads on the fore and aft area when you’re rotating,” he said. “The grouting underneath the hull to share the load during the pivot is very important because the caissons filled with water to help the roll will add more weight bearing load.”
To support the salvage operation, there will be two main offshore construction vessels and a variety of smaller vessels, said Banks. There will also be a fleet of anti-pollution vessels.
The project will require hundreds of workers, said Farrell, adding that those working on the project will also have to be rotated out, which will increase the demand for qualified workers.
“This will take a lot of people from around the world, given the extent and duration of the job,” Farrell said.