Nearly two years after the Costa Concordia capsized off the coast of Tuscany, engineers are making a historic attempt starting Monday to salvage the ill-fated vessel, which lays half-submerged and crushed against reef.

Thirty people died and dozens were injured in January 2012 when the cruise liner smashed into a reef and ran aground at Isola del Giglio.

Plans have been underway to remove the wreckage without causing damage to the environmentally protected waters that surround Giglio Island.

Rather than use explosives or chain saws to dismantle the 115,000-ton vessel in its spot, the Italian government chose a two-step process known as parbuckling and re-floating. If they are successful, the ship can be towed away in one piece.

The process could be one for the history books: the engineering feat has never before been conducted on such a large vessel.

The process is expected to take at least eight hours and could last up to 48 hours. Here’s how it is expected to happen:

Parbuckling

Starting at dawn Monday, engineering teams will attempt to parbuckle – or rotate -- the vessel into an upright position. The most critical time is expected to come in the first hour of the operation, when the ship will be removed from the reef.

Dozens of pulleys wrapped around the ship’s hull will slowly hoist the ship at a rate of three metres an hour, while tanks filled with water on the side of the ship above water will provide the extra weight required to rotate the ship upright.

Salvage master Nick Sloane said Sunday that in testing the machinery, the ship had already lifted about 10 centimetres, indicating that it can be pried loose from the rocky reef.

“We know that … she is lively enough to move,” Sloane told reporters.

Re-floating

Once the ship is in its upright position, teams will have to restore the buoyancy lost when water flooded the interior after the disaster.

With the help of hydraulic pumps, tanks located on the submerged part of the ship, will be filled with air to help restore the ship’s buoyancy and make it ready for towing.

If the ship can float, it will be towed to a shipyard and converted into scrap metal.

What’s already been done

Months of intensive preparation, involving round-the-clock work from hundreds of personnel from 21 nations, has led to Monday’s attempt to remove the wreckage. In November, Costa and the joint engineering team announced the completion of the wreck stabilisation, which will prevent any sinking or slipping along the seabed. Later, workers installed a false bottom on which the ship, once upright, could rest.

With files from The Associated Press