Costa Concordia, 80 deg list, really scary !!

Discussion in 'Stability' started by smartbight, Jan 15, 2012.

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  1. Pascal Warin
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    Pascal Warin Junior Member

    It seems you are not willing to discuss precisely the Costa Concordia case.:confused:
     
  2. Heiwa
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    Heiwa Naval architect

    Is this adressed to me? My analysis of the CC case is at http://heiwaco.tripod.com/news8.htm and I am of course willing to discuss it here or in PM.
    Do you find anything wrong with my analysis? Do you think watertight doors are permitted in store and crew compartments to start with?
     
  3. Hawkboat
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    Hawkboat Junior Member

    < removed> you seem to raise lots of questions about expert opinions without giving any countering evidence.

    As an example, what significance do you see in questioning whether the port rudder and propeller are missing? You can't see it on a grainy, IR video. So what? If they are missing, so what? Do you think someone staged this sinking? Who?? Mossad? The Knight's Templar? Wonder Woman? Poseidon's estranged ******* child from his tryst with the sea-witch in The Little Mermaid?
     
    Last edited by a moderator: Feb 20, 2012
  4. Heiwa
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    Heiwa Naval architect

    <removed>

    Topic is the CC 80° list, which occured twice before/after the mysterious capsize January 14. Try to focus on it. ;)
     
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  5. Hawkboat
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    Hawkboat Junior Member

    <removed>

    I asked you a specific question about CC - what is the significance of the port rudder and prop being potentially missing? Awaiting your answer.
     
  6. Pascal Warin
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    Pascal Warin Junior Member

    Hawkboat, you are loosing time answering this.
     
  7. Heiwa
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    Heiwa Naval architect

    Looking at the IR video of the port flat bottom above water after capsize I couldn't see any port rudder/prop so I thought they had been ripped off in a second contact ... as reported on my web site. Later u/w videos show a prop and rudder in place. Maybe the prop/rudder didn't touch the rock that ripped open the side? Also reported on my web site. The u/w videos are not very professional as we do not know where we are. It must be a very funny underwater rock just ripping open the ship's vertical side and not touching rudder/prop. What do you think?

    I am actually more interested in the capsize that tipped the ship 90° onto the shore. What do you think proximately caused it? The poor Master? But he wasn't on the ship then! I think it was open w/t doors! What do you think? Do you think w/t doors are permitted by SOLAS in crew and store spaces? If you do, I think you are wrong!

    Thanks for asking specific questions. Pls reply to mine.
     
  8. Starbuck1
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    Starbuck1 Junior Member

    Many small compartments and unbalanced flooding

    I'll propose the following as the cause of capsize.
    At the time of grounding, the ship has a modest starboard list of 13-20º and is well down by the stern, at least 3 meters, or more. As can be seen from the photos of the ship aground, lights on, boats still in starboard side davits. The low stern causes flooding of the mooring deck/bulkhead deck aft, and probably along the passageways progressively going forward. Quite possibly through exterior "watertight" hatches, passages and doors that were opened for escape. When it reaches openings below decks, downflooding increases. All on the starboard side. All of these decks are heavily subdivided into small cabins, some doors open, some not. So flooding is not quick. And the main vertical vents such as the stairwells are close to the centerline. As downflooding continues, air is pushed out, or over to the high port side. So we have a ship with badly compromised stability, gaining weight (5-10,000 tons over an hour) steadily on one side while the other side is staying relatively buoyant with trapped air. For an hour the process is gradual and increasing as she sank deeper, until the critical point is reached, then over she went. And with 14 decks of superstructure, they are top heavy when buoyancy is lost.
     
  9. IEWinkle
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    IEWinkle Retired Naval Architect

    See my posts 57 & 58 plus following discussion on http://www.boatdesign.net/forums/boat-design/simulating-costa-concordia-41365-4.html for the lead up to your proposed scenario. There must have been some progressive flooding of the starboard two decks below the lower passenger deck (bulkhead deck), probably from the access to the machinery spaces through WT door(s) left open, to give the initial list of approx 13 degrees to starboard shown in the night-time grounding shot. Once the water reaches the bulkhead deck within the superstructure on the starboard side the list will increase dramatically as you suggest. Photo evidence already shown on TV documentaries shows manually cleated, hinged, WT doors (held open against the longitudinal bulkheads at the time of the black out) along the passage ways of these wing decks outboard of the engine casing.
     
  10. Starbuck1
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    Starbuck1 Junior Member

    IEWinkle, Excellent posts. I hadn't seen the video with WT doors held open.

    I agree with Nettersheim #59, I've yet to see or hear of any evidence of counter-flooding by the crew beyond the captain's wish it were so. By that time the ER's were dead and only the emergency generator was shedding light on the situation, it is doubtful that they had the focus or maybe even anyone in the control spaces to transfer fuel or ballast. A trained and skilled damage control crew that was alert might have done so, but I'd guess that the few men on watch were focused on trying to start the bilge pumps, pump water out and keep essential systems going in the first 10 minutes. Only after power failed completely did they get busy with DC basics like starting the EGen. (Unless there was some sort of automatic leveling system that would transfer ballast automatically with the push of a button, but I suspect that is in the realm of dreams, not reality.)

    When the ship turned around the testimony said there was no list, (suggesting full cross flooding of the engineering spaces) the starboard list only developed after the ship lost way and came under the control of the wind blowing on the huge sides, sending it back to Giglio. Then the low stern and one-side flooding took over.

    Would you agree that the starboard list would tend to trap air under the port side decks and lower cabins, increasing the imbalance, or would it just be the weight and lack of buoyancy to starboard?

    If flooding from the mooring deck openings, (combined with flooding up from below of course), would the height of the water entering on the third deck above the (former) waterline, and flowing further to the starboard side have also accelerated the list significantly, even if the crew decks below weren't fully flooded yet? The reverse of counter flooding in the worst way.

    Has anyone found deck plans of the decks below the lowest passenger deck?

    In the longer bridge videos, I'm stunned by the lack of urgency or curiosity by the bridge crew on the specifics of the damage or flooding. They seemed to be just standing around waiting for someone to report or tell them what to do, or it to become obvious from the failure of systems. Insulated from reality or urgency by the bridge comforts and dependent on the home office until almost the time of the second grounding. Thank goodness for the many individual initiatives of the lower ranking crew and passengers.

    They were lucky to have grounded it when they did, before the stern lost all buoyancy.
     
  11. Heiwa
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    Heiwa Naval architect

    I am happy to see that progressive flooding through watertight (WT) doors aft is discussed as being a (the proximate?) cause of the following capsize.
    Assuming watertight engine compartments #4, 5, 6 and 7 were upflooded due to the side contact damages, what is the new draft and trim on stern?
    Assume that deck #4 is the bulkhead deck and that deck #5 has the mooring deck aft and that the space between decks #4 and 6 is a weathertight superstructure, would deck #5 aft come below water due to upflooding of compartments #4-7. I doubt it. I think deck #5 aft was above waterline after the contact and that the vessel was floating and stable upright. So no down-flooding via doors on the mooring deck is expected.
    Thus, the only possibility that ship trims more on the stern is actually progressive flooding through open W/T doors aft of the engine room (compartment #4).
    Did such doors exist?
    What do compartments #2 and 1 contain? On deck #2? Engine stores? If so I expect W/T doors to be fitted there (and that they should have been closed at sea). On decks #3 and 4? Ship stores? With W/T doors (that are not allowed by SOLAS!)? Actually it doesn't matter because the decks are not watertight and open W/T doors on deck #2 will cause compartments #2 and 1 to fill up (deck #5 aft will be submerged) while GM and GZ becomes 0 = capsize. It will be interesting to see what the Italian Accident Investigation Commission will find.
     
  12. Starbuck1
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    Starbuck1 Junior Member

    IEWinkle, with the 4-5 compartments flooded and the ship lolling at the time of the 180º turn when the starboard list began, would the wind pressure on the side of the ship from the 12 knot breeze on the 100,000 square feet/10,000 square meters of side, with a CE about 50'/15+ meters above the waterline have been sufficient to heel the ship a few degrees to starboard and start the progressive off-center flooding? Thanks.
     
  13. Starbuck1
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    Starbuck1 Junior Member

    Heiwa,

    For consistency of reference, lets use the deck numbering of the plans available, which have the Olanda Deck as Deck 1, the first passenger deck. Below that are 0, A, B, & C decks.

    It appears from the sketchy plans we have that the main WT bulkheads only go up to the top of A deck/bottom of 0 Deck, only one full deck above the waterline, giving a 35' depth of hull. Half of the bulkheads on 0 deck are shown as offset from the bulkheads below, which would be strange for WT bulkheads. The ship's depth is said to be 46', which would make the main WT deck the Olanda Deck, 10' above what the plans we have show as the top of bulkheads. (An anomaly that someone else may clarify or explain.)

    With 4 or 5 major compartments flooded on a 3 compartment ship, all aft of amidships, she will sink by the stern (unless she grounds first) by the well known mechanism of progressive flooding by overtopping of WT bulkheads internally. At some point though, as the first openings in the stern (mooring deck) reach the water level, she will also start flooding through any open or non WT doors or stairs there.

    The smaller WT compartments aft simply aren't large enough to support the weight of the aft half of the ship.

    The weakness with both your theories about many open or improper interior WT doors, and my theory of flooding through the stern WT doors & stairs, is that we have no real data or plans to back up the locations and numbers of the WT and non WT doors or stairs, only speculation and a few uncertain comments by crew.

    We do know however, that by the time CC went aground, and before the boats were launched, the mooring deck/aft end of the Olanda deck was well underwater on the starboard side, and the starboard side at that level has long passageways leading forward, without WT doors in evidence. The exterior doors may have only been weathertight, not designed to support a sinking ship as they go under water. I speculate that persons escaping from the crew's quarters or the Olanda deck may have also left doors open aft, and that there may have been at least one set of stairs going down from the mooring deck to the crew's quarters that could have been open to down flooding. There may have also been hatches or other openings in the deck to facilitate mooring line storage and handling.

    The crew, if not out of their quarters and service areas already, would have been a bit tense between upflooding and overtopping of bulkheads below, and now down flooding from the stern.

    The other question is what was the level of flooding and waterline at the time ship lost all way, the wind blew the ship around 180º, and the starboard heel/list began?

    Yes it will be interesting to see how our speculations and calculations compare with the official investigations. Too bad we'll have to wait a year or more for it.
     
  14. Starbuck1
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    Starbuck1 Junior Member

    Hawkboat and Heiwa,

    IF the port rudder and prop were missing, it would make it likely that the two aft-most compartments were torn open to some degree and flooding. You both know these things are NOT built as break-away installations. Now 6 or 7 compartments filling, all aft? Thrilling...
     
    Last edited: Feb 22, 2012

  15. IEWinkle
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    IEWinkle Retired Naval Architect

    Although I initially thought that loll was likely, my later analysis suggests that the vessel maintained stability through the port a starboard lifebelts provided by decks 0 & A running alongside the engine casing and that once the starboard one started to flood through some form of opening (probably open WT door) the starboard list developed. The early phase of the sinking must have had a port list due to the rock and flooded double bottom compartments to port. This would have reduced from perhaps 7 degrees as the machinery spaces flooded. Any wind effect to starboard after the turn would have been relatively small and probably insufficient to correct the original port list.
     
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