How to Refloat a Capsized Liner

How do you turn over a 952-foot cruise ship that’s capsized on a rocky shoreline?
Marine engineers around the world are speculating on the best way to refloat the Costa Concordia.
Joe Farrell III, a marine salver and naval architect at Resolve Marine Group in Fort Lauderdale, Fla recently returned from Sri Lanka where he salvaged a group of four ships, and also rescued a stranded cruise ship in the Arctic Canadian waters last year. Once the diesel fuel is removed from the ship, a process that will take at least several weeks, it will become more buoyant.
Salvers also may decide to force air into its ballast tanks in order to blow out water that has leaked through a 165 foot gash along the side. The damage would likely be repaired only after workers cut away the jagged edges around the gash and weld steel plates to the hull. The entire operation can be modeled on computer programs that predict the kinds of stresses that the ship can handle.
Once the hole is patched, Farrell said that airbags could be placed under the hull to help stabilize the ship. They may not be enough to right-size it. That would be done using a series of chains and pulleys in a winching system called “parbuckling.”Special marine chains made with 90-pound, 18-inch links are wrapped around the ship and then pulled around a pivot point or “deadman” that is anchored either into the sea bed or onshore. A winch then slowly pulls the ship back over.