Costa Concordia: How a ship twice the size of Titanic is being lifted from the seabed (updated with video)
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Updated: Costa Concordia has been successfully raised. It now needs to be re-floated, and then tugged to a ship-breaking facility to turn the ship into scrap. There is a timelapse video of the ship’s raising embedded below.
On January 13, 2012, the Italian cruise ship Costa Concordia struck a reef off the island of Giglio. The ship grounded at Punta Gabbianara just over an hour later, at an angle of heel of roughly 70 degrees. It’s been stuck on the rocks ever since, a 952-foot, 114,000 ton vessel — tonnage, in this case, can be a measure of size, rather than weight. The estimated weight of the Concordia is around 50,000 metric tons, but that doesn’t include the water trapped inside the hull. To put that in perspective, Concordia is significantly longer and wider than the famous RMS Titanic, and more than double the tonnage.
Ever since the crash, an international team of engineers has raced to rescue the vessel from its current position. While the ship’s oil has been mostly removed, other pollutants, chemicals, and the general eyesore of a 952-foot wreck are cited as reasons to remove the ship from its current position. The timetable for doing so has always been precarious, as the wreck is resting on a rock ledge. Should the ledge fail, the ship would slide down the slope and into considerably deeper water.
After months of preparation, the actual effort of refloating Concordia began early today, as work crews used a system of giant metal boxes, cables, and winches to slowly lever the ship back towards an even keel. The multi-stage process required that crews first reinforce the sea floor, build an enormous metal cradle for levering the giant ship, install huge metal boxes, called sponsons, against the hull, and attach steel cabling across those boxes at multiple points. The cables are then winched taut while the boxes are filled with water. This process is called parbuckling, and its been used multiple times in the past century, often to good effect. The USS Oklahoma was successfully raised following the battle of Pearl Harbor, but the Nevada-class battleship was just 27,500 gross tons and 583 feet long.
The process began this morning and, as of this writing, is proceeding according to plan. Inch by inch, Concordia is rotating off the rock mount where she’s lain, with the formerly submerged area of the ship now fully visible. Despite a three-hour break for a passing storm, the team reports that the operation is proceeding smoothly and that the team will work through the night until the ship is resting on the framework designed to support it. It’s a one-shot attempt — if the parbuckling fails, the ship’s frame will be too badly damaged to allow for a second operation. The hull has to be rotated at precisely the same speed; the longitudinal axis of the ship was never designed to withstand the full weight of the vessel rolling at an unequal rate from an incline as steep. Factor in the damage caused by 19 months of submersion in corrosive saltwater and the warping caused by turning non-load-bearing structures into loaded ones, and the scale of the challenge is enormous.
If the ship is brought back to an even keel without incident, dive teams will begin the next phases of the project. Multiple salvage teams will be used to comb the wreck for the remains of the two missing individuals whose bodies have never been recovered, and to recover the valuables of passengers who fled, leaving them in the ship itself. The condition of the valuables themselves is obviously less than guaranteed.
At the same time, dive teams will begin securing sponsons to the once-submerged section of the vessel. Once completed, the enormous sponsons will act like titan-sized floaties, stabilizing the wreck in the water and allowing it to be towed off the island and towards a ship-breaking facility. The Costa Concordia is a total loss; Carnival explored the idea of repairing the wreck in the early days following the accident, but the degree of damage and the fact that the vessel is a grave site both led to a decision to break the ship up for scrap.
Still, the degree of engineering and effort sunk into removing the ship before the rock ledge gives way entirely is inspiring and the effort is unprecedented. No vessel this large has ever been successfully salvaged before. Once the ocean liner departs, oceanographers and marine biologists will work to repair and repopulate the damaged ecosystem, with the long-term goal of returning the area to a pristine ecological state. More details on the recovery effort are available at The Parbuckling Project.