Costa Concordia salvage operation: 30,000 tonnes of steel, 500 men, USD 800 million

What happens when you roll a giant cruise liner, the length of three football pitches, into the upright position after it has been left to rust in the sea for 20 months? This is the multi-million dollar question that engineers are due to answer today , just outside the little port of Giglio.

Heaving work: Members of the US salvage company Titan and Italian firm Micoperi work at the site of the wreckage of Costa Concordia. The engineers will use a never-before attempted strategy to set the ship upright. Pic/Getty Images

The Costa Concordia, which crashed into rocks off the Tuscan island in January 2012 with the loss of 32 lives, will be dragged erect with cords -- or parbuckled -- to rest on a specially built underwater platform, before buoyancy devices are attached and it is towed away for scrap at a mainland port in the spring. If the strategy seems straightforward, the operation is, in reality, fraught with danger.

Franco Porcellacchia, the director of technical operations at Concordia's owner, Costa Cruises, spelt it out: "It's an extraordinary operation, not because parbuckling has never been done before, but because it's never done with such a big ship." Costa Cruises has stumped up a $400 million bill thus far.

The operation will use a complex system of hydraulically driven jacks and steel cables to pull and push the ship off the rocks and set it upright. The whole operation is expected to take 10 to 12 hours. However, once the wreck is wrenched -- there will be no chance of stopping and starting again.

And if this initial operation is successful the ship will rest on an underwater platform until spring 2014, when the ship will be refloated and towed away.

The salvage operation: in numbers
The amount of steel been used in the fabrication of all the components required to lift the ship is equivalent to four times the weight of the Eiffel Tower

200,000 tonnes
The amount of fuel aboard the ship that was removed as the first part of the salvage operation

1,200
The amount of sacks of cement used to build the artificial seabed, which will be used to let the liner rest on after it is hauled to an upright position

114,00 tonne
The weight of Costa, the biggest Italian passenger ship ever built -- two and a half times as heavy as the Titanic

56
Number of cables fixed to the ship, including 22 keeping it from slipping further out to sea. Each cable is 58-metre (190 feet) long and weighs about 26 tonnes

30
Number of vessels being used during the salvage preparation

Raising Costa

Graphic: Mid Day
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