The US salvage company tasked with removing the wreck of the Costa Concordia cruise ship has said that the unprecedented pro-ject will not be completed before June 2013 at the very earliest.

Titan, which won a joint bid for the project with Italian offshore rig company Micoperi, said that the technical demands of drilling into a granite seabed had slowed progress and winter weather may increase the delay.

“The initial timeline is going to be blown out of the water,” said Nick Sloane, senior salvage master of the US company.

The vessel has a gross tonnage of 114,500 tons – far heavier than the Titanic – and lies beached on its side off Giglio Island in the Italian region of Tuscany.

Before attempting to right the liner, salvage workers are drilling holes into the seabed to support a platform that the vessel will eventually sit on.

“The seabed is granite rock, not limestone or sandstone. Granite rock is the worst kind to be drilling in, especially at the 35 to 40 degree angles that we’re drilling,” Sloane said.

Salvage workers and engineers are working flat out to remove the Concordia, which went aground on the night of January 13, killing 32 of the 4,229 people on board, but Sloane warned that rough winter seas would complicate matters.

“We hope the winter will be mild, but it probably won’t,” he said.

The salvage companies are further securing the wreck to prevent it from slipping off the reef and into deeper water.