One week ago, the Costa Concordia grounded off the island of Giglio. Eleven passengers or crew are confirmed dead. Twenty four people are missing. The ship itself has sunk in shallow water having rolled 80 degrees on its side. What else do we know? Several basic questions remain unanswered.
Where precisely did the Costa Concordia run aground and on what? No one really knows. From the charts there do not seem to be any hazards where the first grounding is supposed to have taken place. The captain steered the ship into shallower water where she currently lies. From Lloyd’s List:
The vessel overturned in the area covered by UKHO’s chart GB1999. But an examination of the chart, which is on a scale of 1:300,000, indicates an area of deep water.
UKHO charts have come in for flak from some parts of the shipping industry. Many of them are of Victorian vintage, compiled with the use of leadweights on lines.
Former master mariner William Todd, now managing director of one of Britain’s largest retailers of the maps, said: “If he was going between Giglio and the mainland, there are no rocks whatsoever shown in between.”
There is a 150 foot long rip in the hull on the port side of the ship with a large piece of stone still embedded in the hull. From the position of the damage on side of the hull, it appears that the ship may have scraped along an underwater ledge rather than hitting an underwater pinnacle of rock which would have damaged the bottom of the ship. There are underwater ledges in the vicinity of the small island of Le Scole off the south-eastern of the island of Giglio. This would put the grounding just slightly to the south of the assumed position of the grounding in the AIS plot developed by Lloyds, but the damage would agree with that observed on the hull. Sky News has an animated reconstruction of this scenario.
Why did the Costa Concordia roll over and why did it roll to starboard? Ever since the capsizing of the Lusitania in 1914 and the Andrea Doria in 1956, in which both were capsizes were related to asymmetrical flooding, cruise ships have been designed to avoid flooding on one side of the ship. If the roll had started once the ship was intentionally grounded by the captain, that would have made more sense. A ship partially supported by the bottom can become unstable and roll. According to passengers, however, the ship started to roll shortly after they felt the initial grounding, well before the captain turned into shallower water. Also, the ship began to roll to starboard, in the direction away from the observed damage. Was there additional unobserved damage on the starboard side? If so, then the question of where the ship initially grounded is again raised and again there is no clear answer. Likewise, why the ship rolled as quickly as it did and why it rolled away from the side of the ship with the observed damage is unclear.
The ship blacked-out after the grounding. Was this cause or effect? The Costa Concordia is a diesel-electric powered ship which means that a loss of the electrical system also means a loss of engines and steering. This could have caused the ship to go off course and hit the rocks. Earlier this year, Cunard’s Queen Mary 2, also a diesel electric ship, suffered a black-out due to a failure in the capacitors in the harmonic filters. Thus far, however, we have heard no such reports from the Costa Concordia. The black-out could have been the result of the grounding rather than contributing to it. Pending a further investigation, no one knows.