(September 12, 2 p.m. EDT) ROME -- The world's biggest maritime salvage operation will take a dramatic step next week when experts attempt to raise the wrecked Costa Concordia from the sea floor off the island of Giglio in central Italy.
In a haunting image, the 125,000-ton cruise ship has remained on its side where it capsized close to the shore of this popular tourist haven January 13, 2012. Thirty-two people were killed.
Italy's civil protection commissioner Franco Gabrielli and technical experts from the salvage operation told a packed media conference Thursday in Rome they were ready to roll the ship off the seabed onto underwater platforms in a high-risk operation expected to last up to 12 hours.
The precise timing of the $800-million "parbuckling" operation will depend on the weather conditions, but experts hope to raise the ship on Monday, after a final evaluation and weather update Sunday.
"This is an operation that has never been attempted before, the undertaking is the first of its kind," Gabrielli said. "We have not left anything to chance."
It's the most ambitious salvage operation ever attempted for a ship of this size, and a team of 500 experts including divers, technicians, welders and engineers from 24 countries have been working around the clock since the disaster occurred to prepare the vessel, which lies on a precarious underwater precipice.
"One of the most challenging things we have with the Costa Concordia is her size and location, sitting finely balanced on two reefs," said Nick Sloane, head of the joint salvage operation being conducted by Titan and Micoperi.
"This is the most challenging (project) we have ever been involved in. She is resting on the side of the hill, resting on a pinnacle."
During the operation, cables that have been attached to several anchor blocks drilled into the seabed will support the ship while 11 huge flotation tanks, or sponsons -- some as big as an 11-story building -- have been welded to the side of the hull to provide leverage and buoyancy as it is rotated.
The actual parbuckling operation will take between 10 and 12 hours as the ship is rotated upright from a 65-degree angle.
When it begins, local ferries and ships will be banned from the area, and a no-fly zone will be created overhead as every stage of the process is meticulously monitored.
Workers will also be looking for the bodies of two victims who have never been found, an Italian passenger and a Filipino crewmember.
"There's no way you can stop the operation," Sloane said. "Once you start, the breakout force is quite large so once we start we continue until it is finished."
Sloane said the biggest risk to the operation is the weather and the strong sirocco winds that come from the south during the fall and winter.
"To go through another winter the ship is going to suffer fatigue," Sloane said. "Time is your worst enemy. You cannot afford to wait."
Despite the intense technical preparations no one is certain what will happen once the ship starts moving.
"There are a lot of unknown factors about the ship, based on the weight and the forces required to break it off," Sloane said.
Costa Cruises said despite the removal of fuel and pollutants, there are still 20 tons of chemicals stored in the ship, and there is "a remote possibility of leakage."
Local residents remain concerned, and Giglio Mayor Sergio Ortelli said this week he was only "moderately optimistic" that the parbuckling operation would be a success.
Ortelli said tourist numbers were down 15 percent this season compared with the season before the crash, but he said numbers had been down 30 percent in 2012.
Once Concordia has been turned upright, another 15 metal boxes, or caissons, will be fixed to the other side of the wreck before it is removed and floated out from Giglio.
--By Josephine McKenna, Cruise Critic Contributor