Were you glued to the TV/Interwebs the day the Costa Concordia was righted? I definitely was. The cruise ship ran aground and capsized off the Italian island of Giglio nearly two years ago, where it has lain as engineers, regulators and environmental activists tried to figure out how best to remove it from the mouth of Giglio harbor. About a month ago, crews worked around the clock to right the vessel and pulled off an engineering marvel.
This is the vessel as she had lain for 18 months:
and this 90 second time lapse video shows the result of 15 months of planning, design, analysis and coordination (and $600 million).Watch it, then come back. We’ll wait.
It sounds almost like a joke: How do you roll a 950 foot, 114,000 ton vessel from on its side to upright? But it’s not at all funny; it’s serious business with lives at risk if not performed properly.
The Italo-American consortium Titan-Micoperi won the contract to right the Costa Concordia and decided to use a process known as parbuckle salvage to pull the Costa Concordia upright. The ship lay on its starboard side on an inclining ledge, so the project had to ensure that it rolled in place rather than sliding into deeper water, and also keep its momentum from carrying it too far in the port direction. Parbuckling uses chains to hold the ship in place while cranes pull on other chains to roll the ship. The video captures this huge cruise ship rolling, so you can’t really see the chains.
The team also had to design and build a cradle for the ship to land on during the rotation so that it didn’t slide and caissons (big, watertight boxes) to attach to the port (up) side that were flooded during the righting to increase the torque on the hull.
On September 16, Titan-Micoperi started tensioning the port-side cables to start the roll of the ship. At roughly 45 degrees, the caissons were filled with seawater and early on the September 17, the Costa Concordia was upright. Severely damaged, with two fatalities still on board, but upright.
What happens next? One alternative is to add another set of caissons to the starboard side for added bouyancy and float the ship to a salvage yard. Another is to load the Costa Concordia on the Dockwise Vanguard for transport. The Dockwise Vanguard is the world’s largest semi-submersible ship; it usually lifts and transports extremely heavy offshore oil and gas platform components but can also carry other vessels and act as an offshore dry dock facility. If this option is chosen, the Dockwise Vanguard will partially submerge and the Costa Concordia will be floated/towed into position above it; the Vanguard empties its ballast tanks and the whole thing rises to a more advantageous water line and (slowly) chugs away.
This is an image of another of Dockwise’s vessels, putting an oil platform into position for installation:
This is amazing, amazing engineering. Size, scope, risk, safety, environmental and economic hazards — as much as possible, the design and project execution team had to simulate every eventuality. There are no “do-overs”.
Earlier this year, I interviewed a number of offshore industry experts on how they prepare for and carry out complex projects. Many use Bentley’s SACS family of products for the analysis of offshore structures and ships. The result is a white paper that I encourage you to read to better understand what’s involved, but I also came away with an appreciation of just how complex this all is. It sounds relatively simple: submerge Vanguard, float on Costa Concordia, increase buoyancy and steam away. In reality, it’s not at all simple. Dockwise uses Bentley SACS to analyze every facet of load-in, load-out and transport and also to ensure that any structures built to support the load are up to the task.
TECON S.r.l. is a finalist here at the Be Inspired awards and will speak later today about its part in the Costa Concordia Wreck Removal Project. I can’t wait to hear what they have to say — but, I’ve got to tell you: competition is fierce in this category!
Top image courtesy of Isjc99; bottom image courtesy of Dockwise Ltd.
