Simulating Costa Concordia

Discussion in 'Boat Design' started by APP, Jan 17, 2012.

  1. peter radclyffe
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    peter radclyffe Senior Member

    dodgem car
     
  2. smartbight
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    smartbight Naval Architect

    For those who still think that the 'stabi' didn't need to be extended on a 12 kn wind + 16 kn ship = 28 kn. Please read the following (this is written by a guy whose job it is to make you go on a cruise):

    Ship Facts: Costa Victoria Review (by Cruise Critic!)
    << Victoria can be a very bow light ship, so even the slightest of swell could be a problem for those with even slight motion sickness...she does move a lot she has quite a pronounced shimmy and she actually bounces too, especially when fully fueled/ballasted. In all honesty I actually felt that her center of gravity was too high and that had been messed up by the balconies being added, combined with the weightless bow and engines/fuel tanks aft. The amount of movement IS excessive for a ship of this size and could put some off booking her, but I do suggest that you give her a try, making sure that if you are prone to motion sickness that you take appropriate precautions. You can obtain anti-nausea pills from reception or the pharmacy free of charge if you think you might require them. My inside cabin on deck 8 was right next to the aft stair tower & elevators and I felt every single roll, pitch & shimmy.
    I would have no hesitation is recommending the Costa Victoria for the Med or for Asia, my only reservations are as I have already pointed out in regard to cabin position & basic 'sea manners' of the ship itself, you will always find some cabins are better than others, just as some ships handle the sea better than others. Do your homework, keep your expectations realistic and you will have a wonderful cruise aboard Costa Victoria. >>

    If you check the Specs on that cruise ship, she is no rubber dinghy.
    This roll motion is felt (not the pitching) on many if not all of these bigger 'tall' ships.
    That is why the stabis are bought '₤x₤' and installed, the QM II has 4.
    I know you guys are tough, <<They have been on cruiseships with more severe winds w/out the stabis extended! >> I saw guys like that riding the bow.
    Here on this cruise, the average tourist is 60 year old and it's dinner time. The Cap doesn't want the hot Minestrone soup to land on the Armani dress the hot lady seating next to him is wearing (hot lady turns cold, dress is ruined + 3rd deg. burn = $,E, ₤.
    So if the stabis are not out yet to keep the cruise critic on deck 8 happy; the Cap calls the wheelhouse and orders them deployed.
     
  3. IEWinkle
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    IEWinkle Retired Naval Architect

    Discovery's version of C C in UK

    Scheduled to run at 10 pm Sunday - might be worth watching!

    Some serious technical errors - lack of any serious attempt to look into the flooding sequence - disappointing!
     
    Last edited: Feb 27, 2012
  4. nettersheim
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    nettersheim Consultant



    Thank you again for this valuable comment and related sketch.

    The "loll state" you mention seems clear, with following elementary calculations.

    If we assume :

    1) an intact GM = 2,50 m /2,80 m (which is according to my experience in passenger vessels a normal figure for this type of vessel which has to fulfill Solas 1974 as amended damage stability criteria)

    2) free surface after flooding (rough consideration based on simple rectangular formulae without taking into account surface permeability, but with reduced breadth in order not to maximize things) L = 50 m , l = 30 m => I = 168 750 m4

    => then with displacement = approx. 52 000 t , reduction in GM is more than 3,00 m (3,25 m) !

    The instability of the vessel when flooded up to let's say a meter below deck A (Solas deck numbering 3) is impressive...
     
  5. janneke
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    janneke New Member

    FYI : the CC was sailing NW and with a NE wind there is an angle of 90 deg difference , in other words a 12 kn side wind, resulting in some areas in a N wind; But what is important is the sea swell, which at 12 kn is not really heavy.
    I always pick a cabin located not too high up and in the middle of the ship where the rotation is (pitching or rolling) the least.
    On the Costa ships i've been, the soups are not even served warm , let alone hot. Many times i've complained about this. To keep me quiet i get a bottle of Prosecco (i'm not making this up) from the maitre D, so i stop complaining. On our last Costa cruise the food was below standard (C Allegra 400 pax) as compared to our previous Costa cruises. The food norm is definitively lower.
    The passengers on this type cruise (it's more of a bus trip who docks in the most touristic places of the med, that otherwise don't attract people this time of the year and which repeats itself week after week, just like they do in the U States. These cruises come very cheap and do not attract the elderly who prefer (and have the money) to go on a more luxuary cruise in the Caribbean or S America. I saw on TV the interview of a German (elderly) couple explaining that they paid 449 eur (!) for this cruise! So don't expect Armani dresses here, more jeans and T shirts and sweaters.
     
  6. smartbight
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    smartbight Naval Architect

    Just a few weeks left to revise and 'polish' your papers for presentation:
     

    Attached Files:

  7. CliffordK
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    CliffordK Junior Member

    So,
    Was the overtopping of the bulkheads?

    Inevitable?
    Preventable?
    A design issue?

    How watertight is Deck 1 Olanda? Stern Access? Square windows? Can windows be opened by passengers?
    Deck 2 Svezia, also with the square windows.
    Deck 3, Belgio, appears to have double doors leading to deck area below lifeboats.
     
  8. Starbuck1
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    Starbuck1 Junior Member

    According to the Discovery Channel Video, the wind was 23 knots, not the 12 knots I'd seen earlier. If so, the wind pressure would be 4-8x greater than we previously thought. Applied to 100,000 square feet of hull side, would this higher wind pressure be enough to heel the ship to starboard during the 180º turn given the severely weakened stability noted above?
    Thx
     
  9. Heiwa
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    Heiwa Naval architect

    Pls note that vessel floats only on the watertight hull. The door seen in the side of the ship is located in the weathertight superstructure and the windows above the door are located in the deck house that is neither watertight nor weathertight, because the ship is not supposed to float on glass windows.
     
  10. IEWinkle
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    IEWinkle Retired Naval Architect

    Sorry to disagree, but the door shown in the photograph in Post 79 is clearly onto the deck immediately below the lowest passenger deck which is the bulkhead deck on this ship. Therefore this door is in the side of the watertight hull.
     
  11. nettersheim
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    nettersheim Consultant

    If it is confirmed that the wind was so, therefore the wind induced moment taking into consideration the huge lateral surface has definitely been able to heel the vessel on starboard side !

    The loll effect would be such that the vessel could have swung from let's say 7° (assumption) on the port side to same angle on the starboard side.
     
  12. IEWinkle
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    IEWinkle Retired Naval Architect

    If you look closely at my Posts 78 & 80 it is unlikely that a 'lolled' condition came into play until shortly before the final grounding. Prior to that, the free water surface in the flooded compartments was well contained by the underside of deck A and the vessel was stable with varying degrees of list. A 'loll' in this situation requires a very large loss of BMt which can only be the result of flooding of large open compartments without the influence of semi-watertight wing deck spaces. At least one of these (to starboard) must have been well flooded to produce such an effect.

    If the vessel was still stable (as I have suggested) at the time of the turn, then any wind heel would have been much smaller than you suggest.
     
  13. Heiwa
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    Heiwa Naval architect

    Well, then the ship is incorrectly designed as SOLAS does not allow door openings in the hull (below the bulkhead deck). Doors are only allowed in sides of superstructures and deck houses. Thanks for pointing out the defect.

    How could the ship drift (due wind?) southwest when the current is from south to north? I would have expected the current would push the ship north of Isola del Giglio.
     
  14. nettersheim
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    nettersheim Consultant

    Thank you very much Prof. Winkle for your comment (post 102).

    I remember perfectly your ideas (in above posts). Nevertheless, you don't think that the free surface effect could have been very large until flood water came below deck A don't you ?

    If I refer to your section 67,5 m fwd of A.P , it could be that just before "tank effect" occured below semi-watertight wing deck space, and reduce the free surface effect, the loss of GM (or BMt) could have been very large ?
     

  15. IEWinkle
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    IEWinkle Retired Naval Architect

    The very first stage of flooding would have had an initial 'loll' as the vessel leaned on the port wing space but this would have quickly corrected to a stable slight port list as the water filled the flooded compartments to the A deck level within the first 10 minutes or so. By the time of the final turn the vessel appears to have been stable near upright (slight port list). Any wind heel would have done little but push the vessel back into the upright condition which may have helped intensify the initial phase of starboard flooding.
     
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