Sloane said the granite seabed also proved more resistant to drilling than imagined. It was “like trying to drill through glass at a 45-degree angle.”
Pressure to make the unprecedented operation succeed is mounting as experts worry that a small window of opportunity to pull off the ambitious feat could shut in a few months.
“Another winter and we might not be able to parbuckle,” Sloane said, using the nautical term for righting a ship. He expressed concern that the ship might compress even further, making it impossible to pull it up upright and into a position so it can be floated away.
The project calls for dozens of crane-like pulleys flanking the ship to slowly start tilting the vessel upright at a rate of 3 meters (yards) per hour. In all, the parbuckling should take about 12 hours.
Yesterday, several welders moved like Spiderman on the now horizontal hull, securing steel pieces that will function like hooks. Steel chains weighing 17,000 tons are being looped under the wreck to help pull it upright. So far, 18 chains have been laid, with the remaining four to be put in place over the next few days.
To work on the tilted wreck, the welders were given five days of climbing training on nearly sheer granite rocks on the island by instructors from Italy’s Dolomite mountains.
Crews are also attaching caissons, or tanks, to the exposed flank of the Concordia. The caissons will be filled with water to add weight and help pull the ship upright.
Identical caissons will be attached to the submerged side of the ship once it’s righted. The caissons on both sides will then be filled with air to float the ship up off the rocks so it can be towed away.
The 230-foot-long gash on the Concordia’s hull has been largely covered with metal plates, though an exposed 10 foot wide hole remains, resembling a truck garage entrance. Crews said there was no need to cover that remaining hole. The gash itself wasn’t repaired, since engineers said it wasn’t necessary. The salvage operation extracted 96 tons of granite reef from the hole, Sloane said.