For over 20 months, the rusting wreckage of the massive Costa Concordia has been marooned off the shore of Isola del Giglio – an Italian island off the coast of Tuscany – a sombre warning of the dangers of naval irresponsibility. It also remains as a national embarrassment for the people of Italy as well as an eyesore for local residents, who claim it has damaged the tourism industry which the island relies upon. The ship ran aground on January 13, 2012, after a crass decision by Captain Francesco Schettina to steer closer to land. This took the ship off the preprogrammed route, at the behest of tourists who wished to have a closer look at the scenic island. This was combined with a series of obtuse actions made in an effort to cover up his mistake after the hull of the ship had already been pierced by the shallow seabed. All in all, the accident cost the lives of 32 people and nearly caused an extreme environmental disaster on an ecologically protected seabed.
Fortunately, the Captain will go on trial for his crimes and likely pay for his insensitivity and selfishness. For the people of Isola del Giglio, the local economy and environment remains at stake until the ship is removed. For the Italian people as a whole, the removal of the ship likely represents a rare chance to salvage their national reputation that remains damaged by the shenanigans of fugitive ex-Prime Minister Silvio Berlusconi and withering economy. The righting of the ship began on September 15th, and the success will likely prove to be not only an enduring source of pride for Italians, but also an engineering marvel not soon to be forgotten.
The technical phases of this display in human ingenuity began on April 21, 2012, when the Italian government granted Titan Salvage (American marine salvage and wreck removal company) and Micoperi (an Italian engineering consultant that specializes in offshore projects) to manage the tender for removal of the colossal ship. The task was an overwhelming one. The ship, weighing over 15,000 tons, weighed on an ecologically protected seabed. Beyond this, the structure of the ship was not only compromised by the initial collision with the shallow seabed, but also by the weight of the ship itself. Laying more or less on its side, the starboard (the right side when looking to the front, or bow, of the ship) side of the ship was being gradually compressed by the weight of the rest of the vessel.
Furthermore, the capsized ship was filled with water, adding further weight to the already gargantuan vessel. An elegant but powerful plan was needed as the success and widely publicized righting of the ship was only a small part of the process.
The first step consisted of stabilisation. The vessel laid precariously on a sloping, rocky seabed, prone to sliding further into the depths of the sea if disturbed, which would have further increased the difficulty of the salvage operation. In order to prevent this, a series of anchors were secured to the seabed, and cables were fastened to these anchors as well as along the length of the starboard side of the hull of the ship; this would prevent the ship from sliding further. Later, twelve turrets were installed along the seabed on the starboard side, and chains were run under the hull of the ship. This was fastened between the turrets and to the port side (left side, when looking to the bow) of the vessel. The movement of these chains was controlled by strandjacks, devices that could be individually controlled by computers. This would be developed in the future for the usage of balancing the ship during righting.
Another major obstacle facing engineers was that the ship had lost much of its natural buoyancy and there was little guarantee that the ship would not roll onto its other side upon righting. In order to prevent this, a resting station for the ship was needed for a more permanent stabilisation upon righting. Constructing this false bottom consisted of two steps. First, a series of grout bags were wedged against the hull of the ship, creating a level portion jutting out from the seabed in an area too close to the ship for supports to be placed and secured. Next, three platforms were placed beside the grout bags, jutting out further into the sea and providing the final stretch of leveled false bottom for the ship to sit on after righting. In order to preserve the ecologically fragile area, both the grout bags and the piles for the platforms were filled with environmentally friendly concrete. After the completion of the false bottom, sponsons (temporary projections off the side of a marine vessel) were welded to the above water port side of the boat. These sponsons provided a longer, leveled bottom for the boat to stabilize after righting.
It was not until after these stages had been completed that the most widely publicized part of the process, called “parbuckling,” took place. Parbuckling, or righting of the ship, did not take place until yet another set of chains was attached to the sponsons on the port side of the boat. These chains were then tightened (also controlled by strandjacks) while the chains that were fastened to turrets on the starboard side were used for stabilisation. The tightening of these chains gradually rotated the boat to an upright position in a fragile operation that took occurred over a span of 19 hours.
However, the process is not yet complete. A process of “refloating” still needs to take place. This will be performed by fastening yet another series of sponsons to the boat, this time on the now accessible starboard side. These buoyant sponsons will provide enough buoyancy to sufficiently refloat the boat after a pneumatic system has removed all the water from the boat. At this point the vessel will be towed to port to be dismantled for scrap metal. This is scheduled to be completed sometime in the summer of 2014.
The Costa Concordia saga has displayed two sides of mankind: the first being the shipwreck that showed us incompetence, selfishness and cowardice. Hopefully it will be the second that we as engineers and people try to emulate: one of boldness, cunning and creativity. For more information on the salvage of Costa Concordia, feel free to visit www.theparbucklingproject.com.
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