Keels and Keels Again!

Discussion in 'Boat Design' started by D'ARTOIS, Feb 9, 2006.

  1. D'ARTOIS
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    D'ARTOIS Senior Member

    When I visited the site of our friends S.A., I found teh item about the yacht Moquini that disappeared in the Mauritius to Durban Race last September. The yacht was found by a French Merchant Mariner who stayed in situ whilst a rescue team made their way.

    What shocked me was the picture of this floating carcass of a yacht, once so beautiful.
    Many people-yachtsmen in South-Africa donated private money in order to start a search and rescue mission. Simonis, the designer of the yacht donated as first SAR 15.000, followed by many donations from fellow-yachtsmen.

    What hit me all in a sudden, looking at the specific damage of the yacht, was the particular, very particular kind of the damage.

    Some time ago, a Dutch family lost two members who were cruising from the US to Europe and went all in a sudden missing.

    Although the Irish Navy made a mess of the salvage of the yacht when she was found in a similar condition to "MOQUINI", it was clearly visible that some great force had ripped the keel from the hull.
    Just similar to what happened to MOQUINI and the damage pattern almost the same.

    In both casualty-cases, the keel was ripped out of the bottem sideways as you clearly see looking at the pictures.

    What could havwe happened?

    I will look up for the pictures of the Dutch Yacht, that was found close to Ireland, so you have something to compare.

    Here is the picture I took from the S.A. site.
     

    Attached Files:

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  2. Wynand N
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    Wynand N Retired Steelboatbuilder

    Sad happening.......

    Brien, if I may take a guess, maybe a whale, perhaps a semi submerged container, but my gut feeling is some structural failure.
    And this type of occurence is the very reason that I am a dedicated to steel hulls with encapsuled ballast.
     
  3. safewalrus
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    safewalrus Ancient Marriner

    Looking at the design of vessel and having a small knowledge of the area my firast reaction is much the same as Wynards, but more inclined to the whale theory as in structural faliure caused by a whale! After all we've been kicking them for many years seems natural that they will eventually get the idea and want revenge, after all they ain't stupid fish are they?
     
  4. Vega
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    Vega Senior Member

    And how about the Sweden Yacht 42 abandoned in the middle of the Atlantic with a moving keel? (no, it was not a canting keel).
    I thought that only happened to Bavarias:D ...and not to boats that cost 4 times more:rolleyes:
     
  5. MikeJohns
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    MikeJohns Senior Member

    Crew members Graham Cochrane, Neil Tocknell, Michael Goolam, Kurt Ostendorf, Sheldon Dickerson and Mark Dickerson were lost in this tradgedy.
    They went missing in September and the vessel was found in February. A 406 Mhz Epirb was triggered but the signal stopped before the search could be conducted. We will never know their final stories. It was thought that they had been run down by a ship.

    It is now apparent that the reason for the deaths is the lack of a decent factor of safety in the keel attachment. A classic example that structurally, strength and weight are at opposite ends of the spectrum. This boat was built light, whether she failed through collision or fatigue is unlikely to be known. Often the failures are blamed on a prior grounding or boat yard damage. Fatigue in these sorts of designs can be a real bugbear.

    Dont blame the whales or submarines, blame the designer, blame the racing rules ! we can do much better in hull strength, it just fails to be competitive under the current rules.
     
  6. CT 249
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    CT 249 Senior Member

    I totally agree that it is beyond belief that keels are so poorly engineered. As the tally of deaths grow, this is becoming even more of a scandal. The ancient plank-on-edge and skimming dishes were banned after far fewer deaths.

    We can't ban and shouldn't ban fin keelers, but why the hell not upgrade this most important of all structures? Surely you CAN design a highly-loaded junction point that is safe - 747s don't lose wings all the time do they?

    It's definitely not the fault of the rating rules, as boats like the S&S Finnisterre type ultra-heavy keel/CB "Sunstone", older Swans (65s etc), Cole 43s, 1907 Fife metre boats, Folkboats, and Contessa 26s have all done very well in major races under IRC and IMS.

    It probably woulnd't even slow the boats down significantly if you had longer, stronger keel roots and tougher keel frames.
     
  7. safewalrus
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    safewalrus Ancient Marriner

    No! Only Once! :cool: :D
     
  8. FAST FRED
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    FAST FRED Senior Member

    "747s don't lose wings all the time do they?"

    No!, there built by Boeing.

    However the tails DO pop off Air Bust's with great frequency, 13 or 14 so far.

    And the wings fell off the Lockheed Electra so the hulks were fostered on the taxpayers & USN as "P3 Orions" by the Senator from Lockheed.

    Not all Mfg's can build reliable structuraly sound aircraft .

    And NONE are pushing the envelope as the "racers" try.

    FAST FRED
     
  9. CT 249
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    CT 249 Senior Member

    Well, let's not push the envelope in something as important as fin keel attachment!

    IRC etc could surely give a .005 rating drop to any new boat with a dirty big keel frame, and measure keel chord at the root and reduce rating a few more pips for long-root fin keels.

    Safewalrus, come to think of it, if a 747 lost a wing once, it would lose another wing a second time when it hit the ground. Yech.
     
  10. sharpii2
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    sharpii2 Senior Member

    The trouble probably lies with ancient keel attachment methods that were plenty strong when the ballast was but a yard away from the hull and the load was distributed almost half the length of the bottom.

    Who would ever attach an airplane wing by just bolting it to the side of the fueselage?

    If one wishes to have a narrow deep keel with the ballast all on the bottom, then one must brace it like a heavy dagger board like you see in a laser but much more massively built. Such a construction would all but dictate a center cockpit because, to be strong enough, the structure would have to reach all the way to the deck.

    If it can't stand at least three times its weight with the boat at 90 deg heel, it is, imho, no where near strong enough. And even that may not be enough. The ability of mother ocean to destroy man made objects is practically beyond limits.

    As much as I hate to say it, I wish we could have the old IOR boats back. I think they were actually safer.

    I absolutely hate the direction yacht design has gone. The boats are now more impractical than ever. They are deep, flimsy, and short lived. And now we have canting keels comming to a theater near you. Imagine the fun when they all start hitting shoals.

    Its not so much the expensive originals that scare me, but the cheaper knock offs that will probably be everywhere in a few years.

    I have always said: The best way to destroy anything is to put a lot of money into it.

    Bob
     
  11. Guillermo
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    Guillermo Ingeniero Naval

  12. Martijn_vE
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    Martijn_vE Marine software developer

    I'm not sure whether it takes 2 or 4 bolts, but the wings are bolted on a 747. Flying will never be the same again once you have seen that construction. :eek:
     
  13. Sander Rave
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    Sander Rave Senior Member

    Ehmm...
    Sorry to say so, trains, plains and automobiles are engineerd and build by man like you and me. That should make you think ;-) The only difference in airplane design is the filosophy to build fail safe constructions; for critical systems there is a redundant system and otherwise if something fails, it should fail in a way the system is secured for a safe return.

    For a keel that should be something like structural damage won't let the keel tear off the hull, but what does a malfunctioning keel look like that doesn't affect the hull?! something like a pivot point that only rotates after an exeeded aplied force, and in what direction... It means extra weight at what expense

    Argument against is the unpredictable behavour at (maybe) the most stressed moment on dek, on the other hand what is the alternative?

    just a thought
     
  14. Vega
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    Vega Senior Member

    About the Moquini, some more details here:

    http://www.abyc.org.za/home/

    Guillermo, I don't find surprising the lack of serious technical data about the Match II keel problem. Bavaria is obviously not interested in it, neither the other big builders, because they use similar low cost techniques to fix the keels to their boats.
    Some years ago, here in Portugal the keel of an almost new Dufour (I think it was a 36) "moved" several centimeters up when the weight of the boat was all put on the keel. Another Dufour, this one, a friend’s brand new 32 broke one of the interior structural reinforcements when it was moved to the water (by a crane).
    The problems on the Sweden Yacht 42 are, to me, the biggest surprise. After all that boat is supposed to be an Industry bench mark (and costs accordingly). It is true that the boat had had some groundings and have been repaired...but some groundings should not affect the structural integrity of the boat....and the only information I can find in the Internet about it is this:

    http://www.ybw.com/auto/newsdesk/20051101135051ymnews.html

    Does anybody know more about it?
     

  15. safewalrus
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    safewalrus Ancient Marriner

    If the keel is not an intregal part of the boat your asking for trouble - no more, no less. :rolleyes: Any bolt on has it's problems -

    even 747's (must be f**king big bolts!):p
     
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