Size matters: To right the Concordia — more than twice the size of the Titanic — engineers built platforms, which together were longer than a football field, supported by 21 5-foot-diameter pillars sunk 30 feet into the granite seabed. Bags filled with more than 16,000 tons of eco-friendly cement were placed between the hull, ledges and platform to support the ship’s bulk once it was rolled off its side.
Heavy metal: The operation required 56 chains weighing almost 3 million pounds in total. To right the ship, computer-controlled hydraulic jacks in shoreline turrets slowly pulled 22 chains that ran from the port side under the hull to the shore.
Float your boat: Hollow metal boxes called sponsons — some as tall as 11 stories and weighing more than 500 tons — were welded to the exposed port side. Once the ship was righted and resting on the platforms, more sponsons were welded to the starboard side, making the ship buoyant enough to be towed.
The cost of Costa salvage: $800 million and counting.
Cleanup on Isle Giglio: The wreck’s environmental impact has been limited, with minimal leakage of fuels and waste materials. Post-towing cleanup operations should restore the seabed to its natural state.