blu:kat sunken

Discussion in 'Multihulls' started by Manfred.pech, May 2, 2012.

  1. Manfred.pech
    Joined: Apr 2010
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    Manfred.pech Senior Member

  2. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    BluKat

    What a shame! The guy had spent 5 years building her.......
     
  3. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Is the reason for the bang sound known? Collision, grounding or mechanical/weld failure?
     
  4. Manfred.pech
    Joined: Apr 2010
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    Manfred.pech Senior Member

    There are speculations about an opened seem but the reason for the bang is still not known. The water came in so fast that there was no chance for the bilgepumps or even to localize the leak.
     
  5. Submarine Tom

    Submarine Tom Previous Member

    That would be a "seam".

    No offence, my spelling is atrocious and English is my first language!
     
  6. Jetboy
    Joined: Feb 2012
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    Jetboy Senior Member

    For whatever reason I had thought that most blue water cats had sufficient built in buoyancy that even in the event of major hull damage they would remain floating, or even in the even of one entire hull flooding the other hull would still float the boat. Is that wrong?
     
  7. Manfred.pech
    Joined: Apr 2010
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    Manfred.pech Senior Member

  8. Submarine Tom

    Submarine Tom Previous Member

    Evidently in this case it is very wrong.
     
  9. pool
    Joined: Sep 2010
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    pool Junior Member

    Their www pages / specification mention 7 watertight compartments - strange indeed !
     
  10. CatBuilder

    CatBuilder Previous Member

    They should!! :eek:

    I hope we do find out the cause. Even a speculation by the owner would be good to know, as his explanation is probably the best.

    Only thing I can think of based on the story on the website is a split right down the entire hull, opening all the forward watertight bulkheads and the main area of the hull as well.
     
  11. hoytedow
    Joined: Sep 2009
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    hoytedow Wood Butcher

    "...Als kurz darauf die „Wilson Narvik“ eintraf, habe nur noch der Backbordrumpf des Kats aus dem Wasser geragt."
    "Shortly afterwards, the "Wilson Narvik" arrived, only the portside hull of the Kats have towered above the water."

    According to the link the port hull was towering over the water, described as a capsize. It may still be on the surface.
     
  12. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    It's easy to talk after things have happened, but for the sake of discussion... I don't like the way this has been done:

    1) This alu sheet:
    [​IMG]

    2) Bent and welded into this shape:
    [​IMG]

    3) To give this deck structure:
    [​IMG]

    I think that the structure in the pic retained a considerable internal stress after the elasto-plastic bending, and that stress adds up to loads from sea operations. The amount of stress will depend mainly on the sheet thickness and bending radius, which are unknown at this point. I am not implying that this structure is responsible for the accident, just taking a note of that particular. It's just my personal considerations, because only the builder knows what was specified on the construction plans from designer.

    Second question (non-related to the above considerations), for Alik, Ad Hoc and other more experienced persons with cats of this size - do these two transverse bulkheads visible in this picture and connecting the two hulls:
    [​IMG]
    look like sufficient internal reinforcements for the bridge deck platform of a vessel of that size? Is that how it is usually done? It would be interesting to see a FEA analysis of that structure under sea loads,
     
  13. CatBuilder

    CatBuilder Previous Member

    Whoops... my wording was terrible.

    When I said "hull", I meant one of the two hulls...

    A split below the waterline, on or parallel to the keel that would also pop open forward watertight bulkheads would cause an event like the one described.
     

  14. Bonaparte
    Joined: Sep 2017
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    Location: Koper, Slovenia EU

    Bonaparte Junior Member

    I think I have found his dinghy :(

    26. may 2012 Atlantic Ocean near Azores

    [​IMG]


    [​IMG]

    [​IMG]

    [​IMG]
     
    Angélique and Manfred.pech like this.
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