Engineering teams on the Italian island of Giglio began liftingthe wrecked Costa Concordia liner upright on Monday in one of themost complex and costly maritime salvage operations everattempted.

The vast hulk of the 114,500-tonne cruise liner has lain on itsside for more than 20 months, dominating the tiny port in theTuscan holiday island where it ran aground and capsized on Jan. 13,2012, killing 32 people.

After a three-hour delay caused by an overnight storm whichinterrupted final preparations, salvage crews started the so-called“parbuckling” operation at around 9.00 a.m. (0700 GMT).

Watch live footage of the salvage here.

The first signs the wreck was shifting were registered at aroundmidday as underwater cameras recorded water swirling in the areawhere the metal was resting on the sea bed.

“It's all quite within projections, both in terms ofmeasurements and the way the wreck's behaving,” Sergio Girotto,project manager for contractors Micoperi, told reporters.

In contrast to the accident, a catalogue of mishap andmisjudgement over which the Concordia's captain Francesco Schettinofaces multiple charges, the salvage operation has so far been atightly coordinated engineering feat.

At a cost estimated so far at more than $795 million, it isexpected to be the most expensive maritime wreck recovery ever,accounting for more than half of an overall insurance loss of morethan $1.1 billion.

A multinational team of 500 salvage engineers has been on Gigliofor most of the past year, stabilising the wreck and preparing forthe start of the lifting operation.

The ship, a floating hotel carrying more than 4,000 passengersand crew, sank when rocks tore into its hull after it came tooclose to shore at the start of a Mediterranean cruise.

Marine insurers who have to calculate the cost of covering a newbreed of large cargo and cruise vessels will be watching theproject on Giglio closely, well aware that any problems could havea significant impact on future insurance contracts.

On Monday, Italian Environment Minister Andrea Orlando said thatItaly, which is seeking compensation for the environmental damagecaused by the wreck, should be able to put a figure to its claimonce the damage to the seabed became visible.

NEVER BEFORE ATTEMPTED

Engineers say they are confident the operation will be asuccess, although the procedure has never before been attemptedunder such difficult conditions on a vessel of this size.

“We have done parbuckling before but never on a location likethis,” Nick Sloane, the South African engineer coordinating therecovery for contractors Titan Salvage, told Reuters.

“She is on the side of a mountain on the seabed, balanced on tworeefs and she is a really large ship – she's three football fieldslong, a hundred thousand tonnes plus… So it's never been done onthis scale,” he said.

The operation is scheduled to take 10-12 hours with the mostdelicate phase expected at the beginning, when hydraulic pulleysbegin to shift thousands of tonnes of metal off the rock bed.

“Let's say those were the most uncertain moments because we hadnever been able to say with any certainty how embedded the wreckwas,” Girotto said.

Salvagers are waiting to see how the weakened structure willreact to the strains of being pulled upright and Girotto said itwas still unclear how badly damaged the section of the hull thathad been resting on the ground was.

A series of 11 towers with hydraulic mechanismscontrolling 450 lb cables under the ship and attached to itsside will slowly rotate the vessel until it is sitting on sixspecially built platforms drilled into the granite rock bed.

During the operation, crews will look for the bodies of crewmember Russel Rebello and passenger Maria Grazia Trecarichi.

Once the ship is upright, salvage teams will spend a number ofmonths stabilising it and preparing for it to be re-floated withthe aid of additional giant buoyancy tanks before it is towed awayfor scrap, probably next spring.

On Giglio, residents were hoping the wrecked ship which hasgiven their island worldwide fame would soon be gone.

Giancarlo Farni, who said he was one of the first rescuers onthe scene when the stricken Concordia went down, said the wreck hadbeen in place for long enough. “I saw it sink and now I want to seeit brought upright and taken away,” he said.