Costa Concordia: What happened

Captain Francesco Schettino, now under arrest on suspicion of manslaughter, said the rocks were not marked on maps and were not detected by navigation systems. He later admitted making a navigational error, and told investigators he had "ordered the turn too late" as the ship sailed close to the island.

The ship's owners, Costa Cruises, said the captain had made an "unapproved, unauthorised" deviation in course, sailing too close to the island in order to show the ship to locals.

Crash investigation

Automatic tracking systems show the route of the Costa Concordia until it ran aground on 13 January. Data from 14 August last year shows the ship followed a similar course close to the shoreline, according to Lloyd's List Intelligence. On 6 January this year, it passed through the same strait but sailed much further from the island.

Investigators have recovered the "black box" system similar to those used by aircraft, that record voices on the bridge, as well as radar position and other data, which they hope will explain how the incident happened.

Divers have been searching the ship as it rests on the seabed in about 20m of water. The operation has been suspended a number of times as the ship has shifted position. The sea floor eventually drops to about 100m.

Removing the oil

Before salvage work can begin to refloat or remove the Costa Concordia, there are 2,400 tonnes of fuel in its tanks which need to be extracted.

There are between 15-20 oil tanks that need draining. They are located against the outer wall which means salvage teams can attach a valve to the outside of the ship and drill in to reach the oil, without the oil escaping - a process known as hot-tapping.

As the ship is no longer functioning, the heavy fuel oil can get thick and viscous, making it harder to pump.

To remedy this, a steam-heated element is put through the pipeline to warm the oil, making pumping much faster. The oil will be pumped to a barge and then to a larger offloading vessel.

Sucking out the oil creates a vacuum, so another hole is made lower down the tank to allow seawater to be pumped in, replacing the oil. This also ensures extracting the oil does not cause the ship to shift position on the seabed.

Costa Concordia: What happened

Captain Francesco Schettino, now under arrest on suspicion of manslaughter, said the rocks were not marked on maps and were not detected by navigation systems. He later admitted making a navigational error, and told investigators he had "ordered the turn too late" as the ship sailed close to the island.

The ship's owners, Costa Cruises, said the captain had made an "unapproved, unauthorised" deviation in course, sailing too close to the island in order to show the ship to locals.

Crash investigation

Automatic tracking systems show the route of the Costa Concordia until it ran aground on 13 January. Data from 14 August last year shows the ship followed a similar course close to the shoreline, according to Lloyd's List Intelligence. On 6 January this year, it passed through the same strait but sailed much further from the island.

Investigators have recovered the "black box" system similar to those used by aircraft, that record voices on the bridge, as well as radar position and other data, which they hope will explain how the incident happened.

Divers have been searching the ship as it rests on the seabed in about 20m of water. The operation has been suspended a number of times as the ship has shifted position. The sea floor eventually drops to about 100m.

The super-sized cruise ship Costa Concordia is half-submerged off Italy's Tuscan coast. So what will happen to the 450-million-euro (£372m) vessel?

As divers desperately scour the 1,500 cabins for signs of life, and hopes fade of finding more people alive, thoughts have turned to rescuing the ship.

Maritime salvage specialists already have staff at the scene assessing the Can a stricken cruise ship be salvaged?options.

"Only a few salvage companies could handle a job of this magnitude," says Mike Lacey, secretary general of the International Salvage Union.

"This goes on all the time but you don't hear about it because they aren't as spectacular as this one. But there's always a ship in trouble somewhere."

So what might be the fate of the Costa Concordia in the weeks, months and possibly years ahead?

Search and rescue has priority, that's always the case, says Mr Lacey, but other underwater inspections will be under way to see what damage the rocks have wreaked to the hull.

"You can see the terrific damage above the waterline but who knows what has happened to the starboard side of the hull?

"You can't put a ship like that on the rocks without doing damage."

Date: 2015-02-16; view: 1081