GIGLIO ISLAND, Italy — Authorities have given the final go-ahead for a daring attempt today to pull upright the crippled Costa Concordia cruise liner from its side in the waters off Tuscany, a make-or-break engineering feat that never has been tried in such conditions.
The ship capsized 20 months ago, and Italy’s Civil Protection agency waited for today’s forecast of sea and weather conditions at dawn before authorizing the attempt to right it.
The Civil Protection agency said the sea and wind conditions “fall within the range of operating feasibility.”
The Concordia hit a reef near Giglio Island the night of Jan. 13, 2012, took on water through a 230-foot gash in its hull, and capsized just outside the harbor.
Thirty-two of 4,200 passengers and crew died. Two bodies never have been recovered and may lie beneath the wreckage.
Never have engineers tried to right such a huge ship so close to land. If the operation succeeds, the Concordia will be towed away and broken up for scrap.
Salvage experts had hoped to right the 115,000-ton vessel last spring, but storms hampered work.
Crews have raced to get the Concordia upright before another winter batters the ship against its rocky perch, damage that would boost the chance it couldn’t be towed in one piece.
Salvage master Nick Sloane seemed optimistic in the hours before the operation began, saying testing in recent days actually lifted the 985-foot ship about 2½ inches.
There have been concerns the rocks of the reef on which the Concordia rests were so embedded in the hull, the ship would resist being pulled off.
“We know that ... she is lively enough to move,” Mr. Sloane said.
The operation to bring the ship vertical involves dozens of cranklike pulleys slowly rotating the ship upright at about 3 yards per hour, using chains looped around its hull.
Tanks with water on the exposed side will help rotate the ship upward, using gravity to pull down the exposed side down.
Once upright, those tanks — and an equal number fixed on the opposite side — will be filled with air, rather than water, to help float the ship up off the reef so it can be towed away.
Last week, the head of Italy’s Civil Protection agency, Franco Gabrielli, said there was no “Plan B” if the rotation failed since there would be no other way to try again.
But Mr. Sloane was confident the ship would withstand the rotation.
The most critical time will be the first hour, since that’s when the ship will be detached from the reef.
Mayor Sergio Ortelli has asked for patience from the island’s 1,400 residents. He expects the operation to last 10 to 12 hours.
Since the shipwreck, no major pollution has been found in waters near the ship. Should the Concordia break apart during the rotation — a chance authorities call remote — absorbent barriers have been set in place to catch any leaks.