Refloating the Concordia

Discussion in 'All Things Boats & Boating' started by Minusadegree, Feb 26, 2012.

  1. troy2000
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    troy2000 Senior Member

    The first thing they'll have to do is secure her in place. She's in a precarious perch on two points of rock right now from what I understand, and could easily slide off.
     
  2. bntii
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    bntii Senior Member

  3. DCockey
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    DCockey Senior Member

  4. smartbight
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    smartbight Naval Architect

    Sketch & photos
    http://overheadbin.msnbc.msn.com/_n...wrecked-costa-concordia-unveiled-in-rome?lite
    http://www.nytimes.com/2012/05/19/w...costa-concordia-is-set-to-begin-in-italy.html
     

    Attached Files:

  5. Jonno
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    Jonno New Member

  6. BPL
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    BPL Senior Member

    Who would cover the cost if a cheaper "low ball" operation had failed? It appears much thought has gone into balloon re-flotation on that blog. I'm skeptical however as it begins with "Don't waste time taking the oil out first!"

    Didn't we also hear arguments against balloons early on due to difficulty working around all compartments and interior debris?
     
  7. Frosty

    Frosty Previous Member

    Its scrap now anyway --its covered in Barnacles and unrepairable.
     
  8. sdowney717
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    sdowney717 Senior Member

    full of barnacles and bacteria and algae and mold and mud and rust.
     
  9. mydauphin
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    mydauphin Senior Member

    Having done this kind of work but at a much smaller scale. I can tell you the money vs risk is something else. Any failures and someone will probably die. They will probably have divers doing most of this work and ship can move at anytime. I had a could of barges that I would strap to either side of boat and tie chains under boat as a safety.

    How much does that ship weight again. Quite a structure to hold that weight from slipping down. Whenever I did a salvage the plans change halfway down the middle because of unforeseen conditions, including weather. Sometimes things would break, or just be stuck in the mud. Or the crane would break, or tip over, or ship break in half.

    Murphy is always their to make it harder.
     
  10. Jonno
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    Jonno New Member

    The apparent "weight" of the ship is not nearly the huge problem the pundits make it out to be.

    The "actual" weight of the ship is apparently ~44 600 tons (according to Titan's info). Certainly nothing to sniff at, but there are very important caveats here.

    The full magnitude of this 44 600 ton weight ONLY comes into play IF the ship was hanging over a 90 degree perpendicular cliff - which is emphatically not the case for the Concordia.

    She is lying on a SLOPE. The shallower the angle of that slope, the LESS effect the weight of the ship has on any holding lines. For example, in the extreme case, if she was lying on a ZERO degree slope, there would be absolutely NO tension at all on the cables (they would be slack!).

    As you start tilting the seafloor and increasing the slope, so the tension increases on the cables, until you get to the other extreme, where the ship is freely dangling over the edge of a precipice, and then the cables must take the FULL weight of the ship (ie 44 000 or so tons).

    But the Concordia is lying on a SHALLOW-angled slope. This fact, and the VERY significant effect of the friction of the hull against the seabed, greatly reduce the actual tension that would be on any holding cables.

    Thus holding the Concordia where she is, is not at all the difficult or impossible task it is made out to be.
     
    Last edited: Jun 2, 2012
  11. mydauphin
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    mydauphin Senior Member

    Sooner or later someone has to put some cables on this monster.
    they have to able to take the weight, even a quarter of the weight is massive.
    You have lift it enough get it level. Idea of building structure under it, I believe is flawed. If rock is soft then structure will fail. Rather just lift with barges. These would be huge.
     
  12. Jonno
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    Jonno New Member

    Yes, Titan's platform has to take the FULL weight, PLUS the additional stresses from rolling the Concordia onto it. And on top of this, the Titan plan includes filling large vessels attached to the upper (port) side of the ship to provide extra "leverage" to assist in rolling her upright onto the platform. These add literally tens of thousands of tons to the total effective weight that the platform must handle.

    Titan's method will certainly work, but it is brute force, hugely expensive, dangerously risky to the operating personnel at EVERY step of the way, and one can hardly think of a more damaging assault on the marine environment than this approach (OK, the salvors who wanted to cut the ship up would have taken the cake for that).

    In shear contrast, the internal balloon method is a model of simplicity and safety and is - by far - the very least damaging method for the environment. The very problem of "taking the massive weight of the Concordia" that you allude to, is entirely side-stepped for the reasons explained in my previous post.
     
  13. bntii
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    bntii Senior Member

    Maybe you should be in marine salvage- Do you question why vested parties chose the contractor who offered the 'brute force', 'hugely expensive', 'dangerously risky', 'most environmentally caustic' approach?

    Perhaps the approach selected was the most likely to succeed with the least risk to the environment and carried acceptable cost and risk to personnel...

    Have you done extensive diving in debris filled wrecks?
    Do you have any ideal of the challenges inherent in what you call "a model of simplicity and safety"?
     
  14. mydauphin
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    mydauphin Senior Member

    Many times salvage companies lie as to exact method used. I would take some weight off by lifting bags all around first and blow balloons in damage area to fill Hull, then fill Hull with air.
    It is easy to get it off ledge and floating. Problem is shear size means everything has to be huge,.
    First thing is to stabilized it as quickly as possible. Structure idea under it is dumb, it will take too long to build, and might not hold.
     

  15. Jonno
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    Jonno New Member

    The opinion you have about diving inside wrecks may certainly be true, but this negative opinion has been entirely invalidated by the actual diving experience on the Concordia.

    This experience, based on real-life - not the idle conjecture of us armchair critics - shows diving inside the Concordia is not so dangerous that it CAN'T be done. Nor - and this is my point - is it so dangerous that it should NOT be done.

    It has now been shown to be an entirely feasible and (with acceptable risk mitigation) a safe enough operation to do.

    There has now been VERY extensive diving done deep inside the Concordia. All done methodically and with safety by experienced divers. The debris fields have been mapped. The diving risks are now well understood, and mitigated, by disciplined protocols taking all this experience into account.

    I have yet to see a proper engineering report which authoritatively dismisses the balloon concept on the basis of sound engineering principles. I would be very happy if you could point me to such a report.
     
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