Salvors achieve Costa Concordia parbuckling, the biggest everNov 25, 2013 03:16 PM
Courtesy Parbuckling Project
Salvors are in the midst of their 19-hour Costa Concordia parbuckling operation.
The largest maritime salvage operation, by weight, in history reached a major milestone when Costa Concordia was successfully righted over two days in September.
Titan Salvage, owned by Crowley Maritime Corp., and the Italian marine contractor Micoperi pulled off this massive engineering feat Sept. 16 and 17. The salvage has been going on since May 2012, when the two companies first presented the salvage plan.
It took 19 hours to rotate the wreck of the cruise ship 35 degrees to an upright position on six underwater platforms, according to information from The Parbuckling Project’s website. The wreck is stable at a depth of 98 feet.
On Jan. 13, 2012, Costa Concordia’s captain took the 952-foot vessel, carrying 4,229 passengers and crew, to within 500 feet of Italy’s Giglio Island. The 114,147-gross-ton vessel struck a 96-ton rock and sank, settling on its starboard side at a 66-degree list. Thirty-two people died in the disaster.
Divers found the remains of two victims, missing since the sinking, the Italian Civil Protection Department announced Sept. 26.
Courtesy Parbuckling Project
Daylight reveals the scale of the damage to the uprighted ship.
Titan/Micoperi estimated that the salvage will cost over $800 million, said Franco Porcellacchia, project director for the Concordia Wreck Removal Project for Costa Crociere. The insurance companies are paying for the salvage. The original salvage budget was $300 million.
Now that the wreck is upright and stable, engineers will evaluate the condition of the starboard side, Porcellacchia said. Work to further stabilize the wreck, in case there is extreme winter weather, continued in October. Then 15 sponsons — giant, watertight steel boxes — will be attached to the wreck’s starboard side.
Eleven sponsons are already attached to the port side; four more sponsons will be added to that side. The steel boxes were used during parbuckling as counterweights to help roll the vessel; later, they will be used to refloat it. A pneumatic system will empty water gradually from the giant boxes, providing the buoyancy to refloat Costa Concordia.
No decision has been made yet about which port the wreck will be transported to for dismantling. There needs to be at least 66 feet of draft. The port must provide equipment to handle the recovery and disposal of any waste, high standards for worker safety and environmental protection, and certainty about the time of disposal, among many other characteristics, Porcellacchia said.
The start of parbuckling on Sept. 16 was delayed by just over two-and-a-half hours due to overnight thunderstorms at Giglio Island. There was no one on the wreck during parbuckling, according to Porcellacchia, except when a team went on board to adjust cables.
The entire operation was managed from a control room on the barge Polluce, moored near the bow of the wreck. All commands, such as activation of the strand jacks (pulling machines), opening and closing of the sponsons and information about the wreck’s position, were transmitted via two cables between the control room and the ship, according to Porcellacchia. The 12-member team in the control room, led by Senior Salvage Master Nick Sloane, included a ballast engineer, ROV pilots, strand jack specialists, a software engineer and a design engineer.
Overall, a team of about 500 people from 26 different countries worked 24 hours a day since the salvage started. That group included 140 crewmembers on 30 vessels, 120 divers, 70 welders and grouters, 60 technicians and ROV pilots, 50 engineers, 10 biologists and about 60 other professionals including salvage officers, coordinators and security and health personnel. In addition, Global Diving & Salvage, of Seattle, had a 12-member dive team on site since October 2012.
The greatest concern about the operation was at the beginning. “The initial phase of the parbuckling was one of the most delicate phases of the project, as the wreck had to be dislodged from the two spurs of rock on which it had rested since the incident,” said Porcellacchia. At 0900 local time Sept. 16, the strand jacks, or pulling machines, were ordered to exert the force needed to free the hull from the two granite ridges.
“The operation had to be performed very slowly, striking a balance in terms of the force gradually exerted so that the hull was not placed under high stress,” said Porcellacchia.
The integrity of the hull was a factor that other salvage experts were concerned about.
“That ship had been through a winter,” said Joseph Farrell, president and chief executive of Resolve Marine Group, of Fort Lauderdale, Fla. “That it was still structurally intact in order to make the rotation during the parbuckle — that was the big unknown.”
At 1620 local time the wreck was dislodged from the two ridges by applying a maximum load of 6,000 tons, using force exerted by the strand jacks operating a system of winches and steel chains, according to The Parbuckling Project website. At this point, the wreck had rotated 10 degrees; it had to reach 20 degrees in order for the intake valves of the 11 sponsons attached to the wreck’s port side to reach sea level. As the wreck rotated, the valves were opened for ocean water to flow into the steel boxes, which helped right the vessel. The giant boxes are outfitted with sophisticated air hoses and pumps to create buoyancy.
At 1900 strand jack operations were suspended for maintenance for an hour to avoid slack cables from interfering with tensioned cables. A 10-member team, including two supervisors, went onto the hull using a specially positioned ladder to perform safety checks, Porcellacchia said. At 0000, the ship rotated 25 degrees and no longer needed to be pulled by strand jacks. From that point, the wreck rotated under its own momentum and under the weight of ballast water in the port steel boxes. At 0200 the vessel had rotated 35 degrees. At 0400 the operation was completed.
It took over 16 months to prepare for those 19 hours. “What really struck me is how they made a plan, and were actually able to follow the plan,” said David DeVilbiss, manager of Global Diving’s casualty and emergency response services. “With salvage you are being dealt a situation that you didn’t create with a lot of unknowns. The key to this project was to identify problems ahead of time and to have a solution.”
In the fall of 2012, eight heavy wires were connected to four underwater anchor blocks to keep the ship in place, according to an article in the summer 2013 issue of Crowley’s in-house magazine. Then 12 turrets were embedded in the sea floor on the starboard side of the wreck. Computer-controlled strand jacks were mounted on each turret. Chains were run under the wreck and attached to the top of 11 sponsons, which were welded onto Costa Concordia’s port side.
Two more sponsons, called blister tanks, were attached to the bow, to provide a net buoyancy of 4,500 tons, which supported the bow during parbuckling. The steel tanks were attached to the hull using three anchor pipes installed in the vessel’s thruster tunnels, Porcellacchia said.
Grout bags, filled with the equivalent of 30,000 tons of cement, were placed between the two spurs of rock to support the hull. Six underwater platforms were anchored in the granite seabed next to the ship, and were designed to support 175,000 tons. After righting, Costa Concordia rested on these platforms.
The construction for this project was impressive. As of Sept. 13, 31,000 tons of steel was fabricated, 18,000 tons of grout was used, nine tons of welding rod consumed and 33 kilometers of weld laid, according to Titan Salvage’s website.
Resolve Marine Group’s Farrell praised the companies that did the parbuckling and noted that the success helps the entire salvage industry. “We benefited from the Titan/Micoperi expert operation and their execution of the job. This had never been done before. The engineering was really stellar,” he said. “I am glad that our industry got such nice exposure and it worked out.”
Because much of the wreck was underwater, the salvage also has been an extremely complicated diving operation. Over 13,000 individual dives had been made as of Sept. 13, according to Titan’s website.
Global Diving & Salvage had about 26 divers rotating to fill a 12-member crew at the wreck. There were seven or eight divers from many companies in the water at the same time, said DeVilbiss, who was on-site several times. For every diver in the water, there were four to eight people above water.
“Many dive teams were working at the same time, and you had overhead and above-water activities that directly affected the diving,” he said. “The biggest challenge is being able to coordinate all this and still proceed without getting in each other’s way.” The average dive was about 30 to 40 minutes, most of it deep air diving using decompression chambers. His divers appreciated the historic aspect of this salvage. “I think everyone was pleased and honored to be a part of it,” DeVilbiss said.