Costa Concordia, 80 deg list, really scary !!

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

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  1. smartbight
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    smartbight Naval Architect

    Our final version, which we hope will put your mind at rest :

    1) There was only one area of contact, starting aft of the stabilizer fin, as shown on the 2nd photo with the red arrow above the black scrape marks, starting at the seachest. The fin was extended at the start of the voyage.

    2) The hull, forward, and around the fin is clean and smooth as a baby's bottom. Bilge keels can be seen, all clean, all smooth.

    3) The granite boulder was split with the help of a quarry's old tool: a steel wedge.

    4) The boulder was loaded (scooped) at 15 kn, during the final phase of the ship's side 'impalement' on 'Le Scole' as per QPS movie.

    Drawing of steel wedge attached.
     

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  2. Leo Lazauskas
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    Leo Lazauskas Senior Member

    Lovely work, Smartbright!

    Did you ever discover why the speed increased to about 16 knots before impact?
     
  3. Heiwa
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    Heiwa Naval architect

    @smartbight
    Why was the stabilizer activated at departure? Weather was good, etc. No need to use it.

    Re boulder, it was thus part of an outcrop of an underwater rock (marked on charts?) that the port vertical side of the turning vessel aft of the stabilizer fin first scraped against, while the flat bottom below didn't touch anything. Then the scrape contact with the boulder became harder and the boulder pushed in the vertical side of the ship 3-4 meters (ending 1 meter below waterline - still no contact with the bottom) and then ... finally the 100 tons boulder was sheared off the rock it was part of and landed on the top of the double bottom. The flat bottom of the ship is intact?
    Sounds amazing.

    According your drawing three bulkheads and four w/t compartments were upflooded at once and the result would probably be that the bulkhead deck aft would be submerged and progressive flooding and downflooding of adjacent w/t compartments would start at once ... and the ship would sink on the stern ... with little time to abandon it. What do you think?

    Anyway with AIS/WMS any shipowner can today continuosly monitor the ships' locations and ensure that they never speed by too close to any shore.
    Maybe we should fit every watertight door with a similar monitoring system?
     
  4. Pascal Warin
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    Pascal Warin Junior Member

    The principle for a bulkhead deck is that it is watertight.
    Three compartments flooding is enough to sink such ship.
     
  5. Pascal Warin
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    Pascal Warin Junior Member

    Great job !
    It is rather clear now ; and a bad case for the master.
     
  6. Heiwa
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    Heiwa Naval architect

    No, the bulkhead deck is not watertight as all stairways down to the watertight compartments below pass through it.
    Only the hull up to the bulkhead deck and the bulkheads up to the bulkhead deck are watertight.
    Above the bulkhead deck is a weathertight superstructure.
    It would appear Costa Concordia survived flooding 4 watertight compartments and the bulkhead deck (aft) was just above damaged waterline and the ship was floating and stable (upright) for at least 2~3 hours enabling successful evacuation of most persons aboard.
    Only later did CC capsize 90° to starboard onto the shore (and luckily didn't turn 180° turtle floating upside down). Why the capsize happened need to be explained. I have done an attempt at updated http://heiwaco.tripod.com/news8.htm .
     
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  7. nettersheim
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    nettersheim Consultant


    I disagree with your statement : the bulkhead deck is not watertight.

    SOLAS 1974 (as amended up to 01/01/2009) in force for "Cost Concordia", in Chapter II-1, Reg.2, definition N°5 = "Bulkhead deck is the uppermost deck up to which the transverse watertight bulkheads are carried".

    This why downflooding may happen (confer previous posts). And it is quite likely what happenned on the "Costa Concordia" : with so much flooded compartments, the bulkhead deck has been immersed and progressive downflooding has done its appalling job.

    This is why margin line (approx. few cm below the bulkhead deck line) is there as an extreme limit in this "old" damage stability standard (deterministic rules) which is still ruling 85% of passenger vessels fleet.

    and ... this is why in my opinion SOLAS 2009 should be permanently questionned (absence of margin line, no sinking limit provided the attained index A is above the required index R) and revised until acceptable safety level is reached !
     
  8. Leo Lazauskas
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    Leo Lazauskas Senior Member

    Interesting pages. Thanks.

    Do you think that the insurance companies will pay out, or not?
     
  9. Heiwa
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    Heiwa Naval architect

    Nobody I know would like to pay a total loss of €415 million minus €30 million deductible if they could avoid it. So leading underwriter may suggest that shipowner was not diligent and thus ... insurance is not valid as per clear conditions of the policy.:rolleyes:
     
  10. powerabout
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    powerabout Senior Member

    lets wait and see if the relatives of the dead sue the captian/carnival or class
     
  11. IEWinkle
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    IEWinkle Retired Naval Architect

    I have given a full explanation of how this could happen at: http://www.boatdesign.net/forums/boat-design/simulating-costa-concordia-41365-4.html#post529743
    She was not upright at the point of grounding with the bulkhead deck well underwater at the starboard aft corner (about 3 m). Up to the point of final starboard list, the bulkhead deck had up to 2 m freeboard at the after end despite 4 or 5 compartment flooding. It is clear that not all the damaged spaces flooded above the line of side damage (outside the line of engine casing) which enabled her to survive an otherwise fatal flooded comparment configuration until some form of progressive flooding, primarily to starboard, led to her final capsize and sinking.
     
  12. Pascal Warin
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    Pascal Warin Junior Member

    You are right I mixed up as bulkhead deck should be weather tight not water tight.

    There is nothing like margin line in new SOLAS but survivability factor s is linked to some points not being immersed :
    BTW margin line was a relic of former "permissible lengths" calculation.
     
  13. smartbight
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    smartbight Naval Architect

    The Captain must keep two things in mind (so the cruisers go back home with nice pictures and tell their friends, that they should too, go on a cruise, and for Capt. to get his Christmas bonus):

    A) Make the cruise as interesting as possible = go close to shores (gunkholing if possible). A mile away is too far. You don't see nothin !

    B) Make it as comfortable as possible for the average 60 y old cruiser. With that low GM= tender ship; you stick those fins out a lot. Especially around dinner time. You don't want that waiter carrying that tray loaded with 10 plates of spaghetti a la bolognesa dumping it on your wife's Armani dress :mad:
    Not at all. Statics ME 211 & Dynamics ME 240, basic eng. courses is all you need.
    The 'kicker' is the steel wedge (a standard tool in granite quarries). The sharp boulder was happily doing its job, slicing inside and riding the double bottom stiff upper ledge (as described by IEWinkle in previous posts) and had no intention of going on a cruise, until it was 'wedged' out of its spot at 13.1 knots. All of the above with the ~10>15>20 ? deg, sudden, but slow roll, since all that tall superstructure above the W.L. kept on bowing in a salute toward the shore, as ordered !
    Looks like the port side is. Do not despair, they now say that the stbd side will need some TLC.

    The drawing is very preliminary (using bhds shown on travel agents' brochure) and we hope Prof Winkle can take a look and help us correct it to match his excellent descriptions in the other threads.

    With participation and informed feedback from all members we are slowly piecing together this 'giant' puzzle. Also a good refresher course in damage stability !
     
  14. Heiwa
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    Heiwa Naval architect

    I like MSC.1/Circ.1380 10 December 2010 Annex 1.2 about GUIDANCE FOR WATERTIGHT DOORS ON PASSENGER SHIPS WHICH MAY BE OPENED DURING NAVIGATION a lot:
    1.2 In order to maintain watertight subdivision, while allowing for the safe and effective operation of the ship, all watertight doors are to be kept closed during navigation, except in certain limited circumstances. SOLAS regulation II-1/22.3 (previous SOLAS regulation II-1/15.9.2), allows a watertight door to be temporarily opened to permit the passage of passengers or crew, or when work in the immediate vicinity of the door necessitates it being opened. In this case, the door must be immediately closed, when transit through the door is complete or the work is finished. Additionally, SOLAS regulation II-1/22.4 (previous SOLAS regulation II-1/15.9.3) permits certain watertight doors to remain open during navigation but only if considered absolutely necessary to the safe and effective operation of the ship's machinery or to permit passengers normally unrestricted access throughout the passenger area. This determination is made by the Administration after careful consideration of the impact on ship operations and survivability.
    Why do you think SOLAS allows watertight doors to be kept open to permit passengers unrestricted accss throughout the passenger area?
    But not the crew? And not the stores? Or the laundry? Or whatever.
     

  15. Pascal Warin
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    Pascal Warin Junior Member

    You were never on board a vessel, were you ?

    Crew is allowed to pass any door under provision that they close it immediately.
    Passengers are not supposed to touch commands.
     
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