The cruise liner Costa Concordia is seen at Giglio harbour, Giglio Island, Italy. Picture: Alessandro Bianchi

Giglio Island, Italy -

An unprecedented operation to refloat the shipwrecked Costa Concordia was set to begin on Monday in Italy, with salvage workers attempting to raise the rusty liner from its watery grave on the shores of a rugged Tuscan island.

Ship owner Costa Crociere, Europe's biggest cruise operator, said engineers would begin lifting the ship around 04h00 GMT, two and a half years after it sank off the island of Giglio in a nighttime disaster that left 32 people dead.

“It's a very complex operation,” Franco Gabrielli, head of the civil protection agency overseeing the salvage, told a crowd of reporters on the island on the eve of the start.

The port was a hive of activity, with curious holidaymakers and local residents watching a 350-strong team of divers and engineers carrying out final checks of the ship.

The liner will be refloated over a six-to-seven day period and then be towed away to Genoa port in northern Italy for scrapping where it is expected to arrive later this month.

The most delicate part of the venture will be Monday, when the 114 500-ton vessel is raised two metres off the artificial platform it has rested on since it was righted in a dramatic operation in September.

Air will slowly be pumped into 30 tanks or “sponsons” attached to both sides of the 290m Concordia to expel the water inside and raise the ship.

It will then be towed away from the shore and moored using anchors and cables. Thirty-six steel cables and 56 chains will hold the sponsons in place.

“The risks are that the ship could bend as it is raised, or the chains underneath it could snap,” said Nick Sloane, a globe-trotting South African salvage master who is in charge on the technical side of the operation.

“There will be 42 people on board during the first manoeuvre. If disaster strikes we will evacuate through emergency escapes on the bow and stern,” said Sloane, who will oversee from a control room on the Concordia itself.

The whole operation is expected to take around six hours.

If all goes well, all the sponsons would be lowered into position on Tuesday and Wednesday.

“That will be the point of no return,” senior engineer Franco Porcellacchia said.

The main refloating operation is set to take place between Thursday and Saturday, when air will be pumped into the tanks to raise the ship and the emerging decks will be cleared of any debris and checked for structural damage.

Final checks will then be carried out before the Concordia is dragged off on its final Mediterranean journey.

The area is in one of Europe's largest marine sanctuaries - a haven for dolphins and whales - and environmentalists have warned about the dangers of toxic waste or fuel leaking into the sea as the ship is raised and towed.

“It's an unprecedented operation and, as with anything being done for the first time, there are risks. But we are confident,” Porcellacchia said.

The Concordia - twice as big as the Titanic - crashed off Giglio on the night of January 13, 2012, forcing many of its 4 229 passengers and crew from 70 countries to jump into the sea as lifeboat pulleys failed.

The ship's captain Francesco Schettino is on trial for manslaughter, causing a shipwreck, and abandoning the vessel before all passengers had evacuated.

Four other crew members and a Costa Crociere executive have plea-bargained and the company has accepted limited responsibility as Schettino's employer.

On the night of the disaster, survivors were fed and clothed by locals, with many taking shelter in the tiny church facing the port, where priest Lorenzo Pasquotti led a solemn service on Sunday evening in memory of the victims.

The body of Indian waiter Russel Rebello is still missing and there will be a search for his remains during the refloating.

Local residents said they would be watching anxiously.

“We really hope it's going to go well. If, God forbid, the ship does sink, I only pray it does so far away from the island, en route to Genoa,” said Giovanni Rum, 36, as he played with his nephews on the pier in the sunshine.

Shopkeeper Silvia said the residents are now looking forward to “waving farewell to the rusting hulk blighting our once pristine shoreline”. - Sapa-AFP