Capsized32 people died when one of the world's largest cruise ships partially sank after running aground off Italy's coast in January, 2012. An unprecedented effortto re-float the ship is under way. Click on the arrows to explorehow it works
AnchoringThe partly-submerged wreck rests on the steep seabed off Giglio with a 50m gash in its hull. The first step was attaching 11 anchor blocks to the hull to keep the vessel from slipping further down the seabed and sinking completely.
False bottomGrout bags are placed in the empty space between the two huge chunks of granite rock on which the wreck is resting. The bags are filled with cement to create a stable base for the hull and six underwater platforms are built for the ship to rest on once the vessel is tipped upright.
CaissonsEleven huge empty metal containers, known as caissons, are welded onto the port side of the 952-foot long ship. Chains are attached to the caissons and run to the underwater platforms.
ParbucklingRotating the ship back to its upright position takes hours and is monitored to prevent the ship rotating too far and capsizing. Water fills the caissons and strand-jacks pull the boat seawards until it’s upright.
More caissonsAs the ship rests upright on the false bottom, four additional caissons are welded to its port side. 15 caissons are welded to the starboard side of the ship after engineers are satisfied that no further repairs are needed on the previously submerged part of the ship.
Re-floatingThe water filling the 15 caissons on either side of the Concordia is pumped out with compressed air, and the ship rises up from the platform and begins to float.