Last Friday (January 10, 2014) Costa Crociere and Titan-Micoperi held a press conference in Rome to update the status of the removal of the wreck of Costa Concordia. This is part of the information distributed there.
Index of other information distributed
The removal of the wreck of the Concordia is an extremely complex technical engineering feat – considered the most daunting salvage ever attempted on a ship of its size – with the deployment of the finest international expertise, state-of-the-art technology and unprecedented financial resources.
The priorities of the project were clear from the outset: respect for the environment, workplace safety and protection of Isola del Giglio’s socio-economic fabric.
Cost considerations played no part whatsoever in the decision-making process. The world’s best cutting-edge technical solutions were chosen even though this led to a significant increase in outlay. According to current estimates, the total cost of the salvage exceeds 600 million euros. The size of this investment gives a good idea of the scale of the project, although not one cent of public money is being spent.
Activity at the site has continued nonstop: about 500 salvage operators worked round the clock in shifts, 24/7, during the preparations for parbuckling; around 200 technicians will be involved in the work leading up to the refloating operation.
The first step was defueling, also known as “debunkering”, which was vital in terms of protection of the marine ecosystem. For this operation Costa Crociere commissioned the world’s leading salvage experts Smit Salvage BV, who in turn worked with the talian firm Tito Neri srl.
Preliminary work began at the end of January 2012 while the actual pumping out of the oil began on February 12, 2012 and ended on March 24, 2012. A total of 2042.5 m3 of fuel was removed from the ship.
This extremely complex and delicate operation was completed successfully without any discharge into the sea.
Collection and disposal of waste and sewage
On January 14, 2012 the recovery of material floating on the surface began, conducted initially by the emergency services and subsequently by Costa Crociere. On March 13, 2012 the operation to remove the sewage ended, Smit Salvage BV and Tito Neri having recovered a total of 240 m3.
At the end of the debunkering, on 25 March 25, 2012, the recovery of material deposited on the sea bed started: in total 24 tons.
WRECK REMOVAL PROJECT
On April 21, 2012 Costa Crociere announced that, after reviewing the bids of the six finalists, it had awarded the tender for the contract to remove the ship in one piece to the international marine salvage consortium Titan-Micoperi Srl, a joint venture between Titan Salvage, a U.S. company owned by Crowley Maritime Group and a world leader in the recovery of wrecks, and Micoperi, an Italian company specializing in engineering and installation of offshore structures and undersea pipelines.
The winning recovery project was chosen based on stringent criteria, 90% of which referred to environmental protection, safety and the socio-economic fabric of the island community. That cost was not a key factor is underlined by the fact that the successful bid was actually the most expensive of the six submitted.
The wreck removal project includes contributions from some of the world’s top technical engineering experts, notably leading international naval and offshore engineering, architecture and design firms such as Ceccarelli Yacht Design, Studio Tecon of Milan, Spline of Venice, Overdick of Hamburg and the Dutch underwater solutions provider Disa International. There have also been contributions from consultants such as RINA (Italian Shipping Register), D’Appolonia and Rome’s Università La Sapienza. All the work involved is being performed by industry leaders like the Italian companies Fincantieri, Cimolai, Rosetti, Trevi, Fagioli and Nuova Olmec, Gas & Heat and the British enterprises Furgo Seacore and FoundOcean. The companies charged with underwater drilling and engineering are global players in their segment and have worked for large oil and energy corporations.
Work on the removal of the wreck from Isola del Giglio began at the end of May 2012 following approval by the Service Conference convened by the Italian Government Emergency Commissioner Franco Gabrielli.
The salvage plan can be divided into 5 phases.
In November 2012 the anchoring and stabilization of the wreck were completed, thus preventing the ship from slipping or falling off the steep spurs of rock on which it was perched at either end and enabling the subsequent work to be carried out safely, even in adverse sea and weather conditions.
Stabilization was carried out by securing four anchor blocks to the sea bottom between the center of the wreck and the coast. Later, seven more anchor blocks and 11 towers were installed, for use during rotation of the ship into an upright position, the so-called “parbuckling,"
On top of each tower are two strand jacks with a hydraulic mechanism for pulling cables, individually controlled via computer. Each strand jack operated a cable connected to a steel chain (each link of which weighs 205 kg) going underneath the wreck so that it could be attached to the offshore side of ship. This system was used to offset the forces bearing on the hull during rotation and guarantee that it could be turned to a vertical position.
2. False sea bed and sponsons on offshore side
The second phase, completed in summer 2013, was one of the most complex. The preparation of the false sea bed on which the ship came to rest once it had rotated required a great deal of effort, much of which was contributed by a team of around 120 divers.
The false sea bottom consists of grout bags (containing a total of 12,000 m3 of cement) and six steel platforms (three large ones [35 x 40 meters] and three smaller ones [15 x 5 meters]).
The grout bags were used to fill the gap because, as already mentioned, the ship was lying on two underwater reefs with a valley in between. The grout bags have eyelets for easy removal during clean-up operations. The subsea platforms provide a stable base for the upright vessel.
The platforms are supported by pillars attached to the granite sea bed; these were put in place by drilling (21 holes 2 meters in diameter and an average of 9 meters deep) using a closed-circuit system so as not to leave any debris in the sea.
During this phase, 11 large tanks – known as “sponsons” – were welded to the side of the hull above water. They were used during the parbuckling to provide leverage and will subsequently provide buoyancy needed for refloating. These large metal boxes, built by Fincantieri, are of considerable size: 10.5 m x 11.5 m with height of 21.8 m or 33 meters, respectively the equivalent of a 7-storey or an 11-storey building. In addition, two “blister tanks” were attached to the bow of the wreck; again built by Fincantieri, these massive tanks provided around 4500 tons of buoyancy, stabilizing the whole bow and acting rather like a neck brace.
Another four sponsons are still to be installed on the port side, making a total of 15 in all on that side, plus 15 on the starboard side.
The actual parbuckling itself – the uprighting of the ship – began on September 16 and was completed the following day at the end of an unprecedented operation lasting 19 hours. The strand jacks were used to pull the steel cables attached at one end to the nine central sponsons and at the other to the underwater platforms, thereby applying a load of over 6,500 tonnes so as to rotate the vessel 65° back into an upright position.
Since it was raised, the wreck has been resting on the false sea bed at a depth of about 30 meters.
After the parbuckling, in order to guarantee additional stability for the wreck also in the unlikely event of extremely adverse weather conditions during the winter season, so-called “winterization” measures were implemented with systems designed to further improve the stability of the hull on the platforms. More specifically, these measures comprised the positioning of 28 tubular steel braces connecting the sponsons on the wreck to the underwater platforms on the offshore side, the positioning of additional grout bags on the inshore side and the installation of an additional holdback system for the bow.
4. Survey of the wreck and installation of 15 sponsons on the inshore side and the last four on the offshore side
Following the parbuckling, the wreck was surveyed to assess its overall condition, particularly the starboard side, which was previously submerged and inaccessible.
Following this assessment, the engineers determined the structural repairs required ahead of the installation of the 15 sponsons on the starboard (inshore) side. This meant it was easier to make a reliable forecast as to when the ship would be refloated and removed from the island.
The installation of the sponsons is planned to start in April 2014.
The 15 sponsons to be fitted on the starboard side have already been built and are being prepared for installation in the Titan Micoperi Terminal in Livorno. Another four sponsons are still to be installed on the port side, making a total of 15 on this side as well.
Initially, the 30 sponsons on either side of the vessel will be filled with water. A pneumatic system will be used to empty the water gradually, thus providing sufficient buoyancy for flotation.
It is a delicate operation and engineers estimate that it might take several days.
Upon completion of this process, a portion of the hull of about 18.5 meters will remain submerged. After refloating, the wreck will be ready for transportation to its final port of destination for dismantling and recycling.