In the first phase of salvage the Costa Concordia wreck was assessed for damage. The plan to seal the hull of the ship was completed once some stabilizing structures were put in place to keep the ship from slipping into deeper waters nearby.
These structures also served as anchor points for strand jacks which pulled heavy wire ropes attached to the starboard side of the ship. A large steel box called a sponson was added to the port side to act as a counter weight as it was filled with seawater during the parbuckling operation.
Salvage Phase Two
After the first phase of salvage the wreck of the Costa Concordia was upright and sitting on her keel. Anchor points and wire rope have been added where the strand jacks were once positioned.
Stabilizing the Upright Ship
The ship needs to be stabilized for several reasons. Workers will now enter the wreck to remove additional hazardous materials. Privately hired and regulatory experts will gather evidence that was not able to be accessed while the wreck was capsized. Workers will salvage some items and attach stabilization and towing gear for the journey to the ship breaking yard.
The Role of Sponsons
One of the items that workers will fabricate on the wreck is another sponson. This large steel box will match the one on the other side which was used as a counterweight to turn the ship upright with the help of the strand jacks.
While the port side sponson was a counterweight when filled with water, it will become a part of the floatation system in phase two of the salvage. The twin sponsons will be emptied of water as the hull is refloated. Some water can remain in the sponsons for additional stability. The wreck with attached sponsons is about forty percent wider than the beam of Costa Concordia.
Removal of Contaminants
Everything which can cause contamination will be removed from the ship before the towing operation begins. The tow will be fairly long and any loss of control could cause the ship to spill additional liquids.
A cruise ship is a floating city with all the services and waste you find on land. The ship operations themselves are heavily regulated and safety precautions are taken that minimize pollutants from ship operations. The hotel side of the operation also takes many precautions and complies with safety regulations. The items in the hotel inventory are either carefully packaged to prevent spillage or are considered benign if spilled under normal conditions.
Much of what is considered dunnage in the open sea is now considered contaminates because of the location of the wreck in a marine sanctuary. Dunnage is packaging and food waste along with other materials which are usually ground to small pieces before being discharged below the surface while underway. These solid waste products are less of a hazard than liquids which are more difficult to contain. The largest contaminate by volume is the seawater, fuel, and debris mixture that fills the now upright hull.
Remediation of Contaminated Water
Any contaminated water will need to be removed from the hull so the ship will once again become buoyant. This water will be pumped out of the ship and filtered mechanically to remove solids. The water will then be treated to remove fuel and oil in the mixture. This will be done with a giant version of a centrifugal fuel filter. Water and oil will separate in this device because of the different densities. Finally the remaining water will be shipped to a sewage treatment plant where it will be cleaned before being discharged back into the sea.
Some of this operation may take place at the wrecking yard itself to decrease costs under less stringent environmental regulations, but most water will need to be removed for safe towing.
Towing the Costa Concordia to the Breaking Yard
Once the ship is disassembled it will be towed to the breaking yard for disassembly and salvage. The scrap value of such a large ship is very high and salvors are very skilled at extracting all value from a shipwreck.
Removing the Ground Anchors and Parbuckling Rig
Once the wreck is gone the anchors and steel pylons will be removed. The seabed will be returned to as close to the pre-accident condition as possible. Restoration of the reef could include replacing populations of plants and animals destroyed by crushing or lack of sunlight. A formal restoration may not take place in which case the reef will be allowed to return to its natural condition over time.,/p>