MS Costa Concordia

This week, salvage experts have been trying to raise the Costa Concordia, a cruise liner which partially sank near the island of Giglio off the coast of Italy in January 2012. Here’s the quick-fire science on the Concordia and the salvage operation to raise it. Here's your Quick Fire Science on how to recover a capsized cruiseliner...

 - At over 290m long, 35-and-a-half metres wide and weighing in at 44,600 tonnes, the Costa Concordia is a similar weight to the Titanic, but much larger.

 - Recovering the Costa Concordia will be the largest and most expensive passenger ship salvage operation ever, and is estimated to have cost £420m so far.

 - Shipwrecks are usually blown up or sunk, but the Concordia is being recovered in an effort to preserve the nearby Pelagos Sanctuary for Marine Mammals.

 - 2,200 tonnes of fuel have already been removed from the wreck to avoid environmental contamination.

 - For the last 20 months the ship has lain on its starboard side, with the port side protruding from the water.

 - The Concordia ran aground on a sea ledge, but could slide off this ledge if disturbed.

 - To prevent this, workers anchored six steel platforms to the sea bed under the ship to provide a landing pad for it to rest on once righted.

 - 100-foot-tall hollow steel boxes were then attached to the exposed side of the boat. These boxes will initially contain water, which will be replaced with air to provide the buoyancy needed to re-float the wreck.

 - Salvagers have used a system of pulleys, chains and counterweights looped under the ship to pull it upright.

 - The next stage of the salvage operation is to attach custom-made steel boxes to the previously submerged side of the ship. Water can then be emptied from these boxes, allowing the ship to be re-floated.

 - Experts estimate that these boxes should be in place by next spring and hope to complete the salvage operation in summer 2014.