Raising the Concordia

by Virgil Soule. 0 Comments

Whoo hoo! The parbuckling operation was a success and the wreck of the cruise ship, Costa Concordia, now rests upright on a temporary dry dock structure installed on the sloping seabed just outside the harbor on the Isle of Giglio, Italy.

Readers will recall that in the evening hours of Friday, January 13, 2012, the Costa Concordia struck a rocky reef off Giglio Island off Italy’s west coast. It ended up lying on its side partially submerged on the island’s shore. Amazingly, for a wreck of this magnitude, more than 4,000 passengers and crew members got off the ship alive.

For reasons yet to be determined, Costa Concordia, on a northerly course, made a close pass to the Port of Giglio, where it struck La Scole reef just outside the harbor entrance. After striking the reef, the ship continued on north and made a U-turn before coming to rest on the island’s shore. How this was accomplished is still a matter of controversy, however, it seems unlikely that the 115,000-ton ship would simply have been blown there by winds or tides as some claim.

Concordia lay on a little spit of land jutting out from the island’s shore. Apparently it was deliberately beached. This action saved the lives of more than 4,000 people. If the ship had been allowed to sink in deeper water, the loss of life would have been enormous. Concordia’s hull was not compartmentalized. When the hull flooded, it very quickly flooded from stem to stern through the gash in the ship’s underside. The crew wouldn’t have had time to organize an evacuation or, for that matter, figure out how to lower the lifeboats before the ship rolled over and sank.

Almost immediately, the ship’s owners engaged a salvage company to refloat the vessel and tow her off for scrapping. I’ve been watching progress of the work via a webcam provided by the Isle of Giglio.

Refloating the 115,000-ton ship is going to be a major undertaking but is not out of the question. In fact, numerous precedents provide examples of the work needed. About a hundred years ago, for example, the Battleship Maine was refloated in Havana harbor despite major hull damage. During the Japanese attack on Pearl Harbor, the Battleship Oklahoma (BB-37) turned turtle and sank at its moorings. It was successfully righted and refloated. Unfortunately, it didn’t rejoin the war effort, however. On the way back to the Mainland, the burned-out hulk sank in a storm at sea.

In most previous salvage efforts the wrecks lay on relatively flat, muddy bottoms. The Concordia was rather precariously perched on a sloping rocky ledge. The ship still had some residual buoyancy. A winter storm with a strong storm surge could have caused it to shift about and pound on the rocks possibly breaking its back or, worse, sliding off downslope into deeper water. The salvors therefore had some incentive to right the ship and stabilize it before winter.

The plan was to roll the ship onto a huge specially-built underwater platform next to the hull using a method known as parbuckling. Eleven large tanks, known as sponsons, were welded to the wreck’s port side. For the parbuckling operation, the port-side sponsons were filled with water to overbalance the wreck and roll it in a carefully-controlled fashion upright onto the underwater platform. Matching sponsons will then be welded to the starboard side. The sponsons on both sides will then be pumped dry to refloat the wreck for the trip to the salvage yard. That won’t be the end of it, of course. The steel platform will need to be removed and the shore restored to something approximating its original state pre-Costa.

The Salvors still have a considerable amount of work to do, but righting the wreck was a major milestone. The next few months will be interesting to watch as the Costa Concordia is refloated and prepared for its trip off the Isle of Giglio.

Costa Concordia http://en.wikipedia.org/wiki/Costa_Concordia

Island of Giglio Webcam http://www.giglionews.it/2010022440919/webcam/isola-del-giglio/webcam-giglio-porto-panoramica.html

Battleship Maine http://en.wikipedia.org/wiki/USS_Maine_%28ACR-1%29

Battleship Oklahoma http://en.wikipedia.org/wiki/USS_Oklahoma_(BB-37)

Parbuckling project http://www.theparbucklingproject.com/

 

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