One of the more alarming aspects of the sinking of the Costa Concordia was the dramatic roll that the ship took after the grounding. She is now sitting with a list of roughly 80 degrees with almost half of the ship flooded. Passenger ships have been designed to avoid listing when damaged since at least the Lusitania in 1915, when longitudinal bulkheads which allowed flooding only on one side of the ship, accelerated the capsize and sinking. The Costa Concordia however is in a different situation. She is resting on a rock ledge. Once the ship was no longer floating but supported on rocks, she lost stability and rolled on the uneven bottom.
There is now concern that in deteriorating weather, the ship might slip off the ledge into deeper water. Rescue efforts on the ship were suspended indefinitely today when divers heard noises suggesting movement. Thus far, the recorded movements of the ship have been small but if the ship does sink in deeper water the environmental impact from the leaking of the ship’s fuel tanks could be significant. The Dutch salvage company, Smit Tak, has been contracted to pump fuel from the ship and begin salvage operations.
Cruise disaster: Costa Concordia slipping into the sea
Rescue operations on the capsised Italian liner were suspended indefinitely on Monday after the giant ship slipped on its rocky resting place, a firefighters’ spokesman said.
“There was a slippage of nine centimetres vertically and 1.5 centimetres horizontally. We evacuated immediately. This is something we have been worried about,” spokesman Luca Cari said.
“It has been our nightmare,” Corrado Clini said. “The vessel has reservoirs full of fuel, it is a heavy diesel which could sink down to the seabed, that would be a disaster.”
“It is definitely moving,” an international salvage expert, who asked not to be named, told The Daily Telegraph.
“We think the hull has been pierced by a couple of pinnacles of rock but if it starts moving around a lot, it could break free, and that would be a big problem.” The Italian fire service, which is spearheading search and rescue operations, also confirmed that the ship is shifting as a result of the worsening weather off the coast of Tuscany.
What I do not understand is why the ship rolled away from the gouge in the Port side. If that is truly the worst damage that the hull sustained, then why did she not heel over immediately toward that damage and flooding?? You would think that hundreds of tons of rock embedded in the Port side would have had enough of a destabilizing effect on the balance of the hull, that it would have immediately listed to Port, but instead the ship listed almost immediately the other side, easily lifting the significant weight of that boulder out of the water.
I suspect that during the grounding even worse damage was done to the Starboard side, possibly ripping open most of the turn of the bilge, which would explain why the hull listed to Starboard immediately. I also think that the emergency turn about likely increased the heel to Starboard and contributed to the capsizing.
But I keep reading that the 150 gash in the Port hull, that is clearly above the water and is relatively high up on the hull, is the primary damage that caused the sinking. Until divers can do a proper underwater survey and judge the condition of the Starboard hull, nobody can know how badly damaged the hull really is, and they will need to know that before any salvage can begin. But by itself, I do not believe the damage that is visible on the Port side is sufficient to explain the immediate 15 degree list to starboard and the very rapid sinking.
Here’s my take, which is still just speculation but I think pretty reasonable.
There should be two distinct sets of damage to the ship’s hull. The first is on the side from the initial grounding, a 150 foot long gash which took part of the rock with it. After the initial collision with a pinnacle or rock shelf, the ship began to flood rapidly. The captain maintained course to just beyond the harbor and then made a sharp turn to port to attempt to ground the ship in shallower water to prevent her sinking. Where the ship ended up is reported to be rocky. Instead of settling on a flat bottom, part of the ship appears to be being supported on rocks or a ledge. It is likely that she is now impaled on one or several rocky points.
When ships are no longer fully floating, which is to say being supported by the buoyancy of water, but are instead held up by a single or a small number of supports, they lose all the stability provided by the water. That is likely what happened to the Concordia once she was aground for the second time. Because the ship was making a sharp turn to port, the momentum of the ship and the thousands of tons of water flooding the ship would be to starboard, which is how she rolled. When she rolled far enough to reach open ports and doors the down-flooding just kept her going.
So yes, I think that you are right that there has to be damage on the bottom on the starboard side in addition to the visible damage on the port side. My guess is that majority of the initial flooding was from the port side.
With luck we will learn exactly what happened if the investigation is thorough and public.
Perhaps the captain used the massive thrusters to edge the ship into shore and in doing so further added to the listing to starboard. Those thrusters are extremely powerful and can shift huge volumes of water very quickly. In very shallow and especially irregular bottom shapes, these thrusters can be extremely unpredictable and destabilizing. I once saw a cargo ship use it’s thrusters to edge up to a solid concrete dock. The water required to feed the thrusters had to come from under and around the hull which created a cushion of moving water between the hull and the solid dock which actually pushed the hull away from the dock and caused the ship to roll around five degrees. The closer the ship came to the solid dock…the more pronounced the effect was. In the end they had to use the thrusters to give the ship sideways momentum further out from the dock and then shut them down and let the ship drift in.
I don’t see how she could have listed to starboard unless she was flooding on that side. Even the speculation that she touched on an irregular bottom does not make sense. What caused her to lose buoyancy on the starboard side? Were watertight doors left open? Was there damage on that side, too? Did the crew attempt to counteract the heel by pumping water to starboard? Did she ever heel to the port side at all?
As bad as the damage was, the evacuation seemed worse. The fact that the ship did not completely submerge would suggest the accident was survivable, but the steep heel would have created enormous difficulty in moving about. What a terrible way to learn that evacuations must start early enough before the angle of heel itself traps passengers and crew.
I listened to an interview that was conducted with a young woman who was a member of the crew and was very familiar with the ship. She describes being in the aft end during the initial grounding, and she describes the ship beginning to shudder with a pronounced rumbling noise that got louder and louder, and violent enough to knock all of the bar glasses off their shelves. Part way through the grounding, she describes an enormous “BANG” which sounds to me like that boulder lodged in the hull breaking off. She said the rumbling continued for a few more seconds and then stopped.
That sounds to me like the Starboard side being dragged across the rocky bottom, or a part of the shelf that the boulder came from. If you look carefully at the gouge in the side of the hull, it appears to be angled slightly in toward the center of the hull. The damaged plates begin with scrapes and dents, and the damage gets deeper the further aft you go, until you get to where the boulder is, and it is lodged quite deeply in the side of the ship. You can see where the hull stopped tearing and started to bend around the boulder, until it contacted enough ship’s structure to snap it off completely. It looks like the boulder plugs most of the hole it made, and the tear along the bottom of the damaged part does not look large enough to cause the catastrophic flooding that caused the ship to heel to Starboard immediately.
Again, a damaged hull will list toward the worst damage. The ship rolled to Starboard, away from the 150′ gash and tons of granite lodged in the Port side. That boulder is big enough to have significantly affected the weight and moment of the hull, and should have induced a significant list to Port all by itself, but instead, the ship heeled the other direction lifting all of the weight of that boulder up out of the water. The only way that could have happened is in response to major and catastrophic flooding of nearly the entire Starboard bilge spaces. If the hull was indeed dragged over a rocky shelf, the hull could have easily been split open like a zipper on the Starboard side, admitting enough water to overcome the massive weight (and flooding) on the Port side.
There is talk in the media of plans to patch the port side damage, and then just “refloat” the hull. Until they can get deep enough into the interior to inspect the Starboard side, there is no way they will refloat that ship. And if it is as badly damaged as I think it is, the only thing left to do is bring in a few barges and a crane, and start chopping.
We shall see…
It will be fascinating to learn exactly what happened, if we ever do. So far everything is speculation. Modern cruise ships are designed not to list when damaged. Whether the list was due to the flooding remains to be seen. If so, there is something definitely wrong with the design. If so that should be a real concern to the six other sister vessels.
I agree that there has to be major damage on the starboard side of the ship. The initial list was to starboard while the ship was on a straight course. That tells the tale. I’ve seen some underwater photos showing damage. Since the paint is showing in the photo and there is clear damage there I suspect there is a lot more under the ship. She’s done. They’ll have to scrap her. I would bet most of her bottom is ripped open. I’m curious how many of the missing are crew members who were working in engineering that night. I haven’t heard them interview anyone from that department and they would have been the first to know. Did anyone from that area make it off. I believe none of the engineers made it off the Titanic. I only remember one fireman who made it out. Anyone have any thoughts.
After a week, all we really have thus far is speculation. It does appear that the ship started rolling well before the captain made the turn toward shallow water, so my initial thoughts that the roll was related to instability due to grounding are flat wrong. I have just posted about the basic questions to which we still have no answers.
Costa Concordia – One Week Later, What Do We Know? Not Very Much!
Eric, if a vessel has a large list to Port, water is always pumped to the low side or Port side first. If water is pumped to the high side first (Starboard) the vessel would be likely to capsize as the vessel rolled from Port tthrough to Starboard, due to the momentum of the vessel as it rolled.
A good example of this was in Alaskan waters, when the car carrier, “Couger Ace,” had a list of 85 degrees + due to a crew member opening the wrong valve during a ballast water change over.
While this is a dangerous exercise, and great care needs to be taken, it is far better than capsizing.