One of the most ambitious salvage operations ever attempted is expected to start this week off the coast of Italy when operators attempt to lift the Costa Concordia from the seabed where it has rested for 18 months.
The effort could start as early as Sept. 16, though sea and weather conditions could delay it for days. (Click to view live video from the New York Times.)
Once the process begins, it is expected to take at least two days to pull the 114,000-gross-ton ship into an upright position. Hydraulic jacks will be used to slowly winch the ship off of its starboard side and onto a specially constructed underwater platform.
News media from around the world are expected to converge on the island of Giglio to cover the unusual and risky operation.
The project is “extremely challenging” in the words of Nick Sloane, senior salvage master for the team of marine salvage companies hired by Costa Cruises to tackle the job.
Cruise companies have an interest in seeing the first phase of the salvage, called parbuckling, come off as planned. A failed operation could bring a round of second guessing and lead critics to rehash the accident that grounded the Concordia in the first place.
If the initial operation is successful, the Concordia will rest on the platform for months while preparations are made to refloat it. If that is accomplished, it would be towed to a nearby port to be scrapped.
Several factors make the first phase of the operation less than a sure thing. To start with, it has not been tried before on a ship of the Concordia’s size, which makes it, essentially, an unknown procedure.
In addition, the Concordia has been resting on its side in the ocean, subject to storms and in a position for which its structure was not designed. Seawater has increased the risk of corrosion.
Sloane has already said the ship has been compressed about 3 meters, or 10 feet, since it sank. The starboard side of the ship will come under pressure to deform as the cables attached to the port side begin to pull.
A team of about 500 marine engineers, technicians, divers and welders has been laying the groundwork for the big lift. Several super computers have been used to run simulations of the event.
Two firms are directing the project. Titan Salvage, of Fort Lauderdale, is a worldwide marine-salvage and wreck-removal specialist. Italy’s Micoperi has expertise in underwater construction and engineering.
The plan they settled on calls for 15 steel caissons to be welded onto the port side of the ship. During the process, they will be filled with water to act as a cantilever once force is applied to the ship.
A series of plastic bags were placed between the two peaks the Concordia rests on and were filled with 18,000 tons of cement grout so that when the ship tips, it rests properly.
Chains have been wrapped beneath the hull to keep it from slipping down the underwater slope. On the other side, cables passing through hydraulic jacks anchored to the seabed have been attached to the caissons and the underwater catch platform.
Computers control tightening of the multiple jacks to give operators more feel for the delicate process.
Salvage experts say that what is unprecedented about the operation is not the parbuckling technique, but the size of the ship.
The sunken battleship USS Oklahoma was raised after the Pearl Harbor attack in World War II using a similar strategy. But as large as it was, the battleship was only about half as long as Concordia and had about one-quarter of its displacement. Also, the Oklahoma sank in a harbor, so cables to pull it upright could be anchored on land.
The salvage team for the Concordia also faces environmental pressures that didn’t exist during the 1940s. The area off Giglio Island is part of the Mediterranean’s largest marine wildlife sanctuary.
That made it preferable to refloat the Concordia in one piece rather than dismantle it in place, which would have created a very difficult containment problem for debris and hazardous wastes.
If and when the 952-foot Concordia is tilted upright onto its platform, the next phase of its removal would begin. Crews would begin adding 15 caissons to the starboard side, as well, and removing some of those welded to the port side to reduce their weight.
The water in the portside caissons used as a counterbalance to help pull the ship into a vertical position would then be pumped out, and caissons on both sides would be filled with air.
The intention is to refloat the ship, which is now about 65% submerged, so that it is once again maneuverable. It would then be carefully towed by tugs to a nearby port where it can be safely dismantled.
Once the Concordia has been refloated, the sea bottom will be cleaned and marine flora replanted.
The later phases of the project will occur in the winter months, with the final removal of the Concordia scheduled to take place in the late spring or early summer of 2014, according to Italian emergency commissioner Franco Gabrielli.
Gabrielli said the “natural destination” for the ship would be Piombino, a mainland Italian port halfway between Livorno and Civitavecchia that has served as a staging headquarters for some of the salvage work.
Follow Tom Stieghorst on Twitter @tstravelweekly.