AIT Around In Ten

Discussion in 'All Things Boats & Boating' started by Manie B, Feb 7, 2014.

  1. Manie B
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    Manie B Senior Member

    if you stack the weights along the centre line in the middle of the tub it does not self right unless you touch it, a gentle touch causes it to snap upright very fast
     
  2. shantyboat
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    shantyboat Junior Member

  3. sharpii2
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    sharpii2 Senior Member

    That's one of the reasons fore the "Capsize Screening Formula". It favors heavier boats primarily because, if they float upright and carry sail at all, the will probably right from a total capsize.

    The reason for this is because they have a great deal of weight for their water plane area, and get much of their initial stability from weight distribution, rather than leeward buoyancy shift.

    A lighter margarine tub, even with the same VCG as the one in your experiment might end up depressingly stable upside down. There's at least one "Open 60", I know of, that capsized and stayed inverted for months, even though the deep, bulb keel was still intact.

    An AIT boat is going to have a nearly full length waterline and a D/L of close to 1,000.

    My "Football" concept has one of 780, and it is intended to make the voyage in hops.

    The Yrvin 10 is supposed to weight in at at least a ton when it leaves port, IIFRC. It is really more of an ark than a sailboat. It may make it for this reason.
     
  4. Harley1
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    Harley1 New Member

    I'm new here, and this is the first time I've heard of AIT but it doesn't surprise me. Lots of people choose to go as compact and stuff-free as possible. Not all of them can make it, of course, but that's how it is. I've lived in some pretty small spaces, but I wouldn't want to sail and live on a 10-footer. Just not my thing. :)
     
  5. Manie B
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    Manie B Senior Member

  6. Angélique
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    Angélique aka Angel (only by name)

  7. shantyboat
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    shantyboat Junior Member

    B'tugly

    So I am interested in an affordable, relatively fast build boat that is capable of handling some rough water. In my case that means Puget Sound. I won't cross oceans.

    BTugly has a cross section that is not unlike a shoe box. That would imply that once it gets on its side or upside down it would stay that way.

    But could someone help me with this thought? The top would be rounded, and the sides would have the ballasted box keel hanging off the side. There would be 500 pounds of ballast in the bottom of the boat. There would also be weighted sideboards. With the skipper shifting his own weight inside, would that ballast and skipper movement still not be enough to right the boat?



    http://www.triloboats.com/AiT10x4.pdf

    [​IMG]

    [​IMG]
     
  8. Manie B
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    Manie B Senior Member

  9. rayman
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    rayman Senior Member

    Manie, here is a frenchman who was removed from his little boat in Torres Strait a few months back. He was 100 days out from french polynesia, his starting point. The boats name is "April Fool"
     

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  10. Manie B
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    Manie B Senior Member

  11. DriesLaas
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    DriesLaas Weekend Warrior

    Something I do not understand: Experienced bluewater sailors please help me out.
    Sailing these small boats, there seems to be a very high probability of being knocked over. I was watching the video of Ant Steward over the weekend, who went around on an open boat, which was a modified Dix TLC19, and he was knocked down many, many times.
    I also am happy to get my head around the fact that with the correct ballast ratio and position, the boat will self-right given enough wave action( If I remember that was the main mechanism of righting on capsized yachts, and not anything the crew does.)
    What I wonder about is the probability of the rig surviving a knockdown, and whether it can withstand the violent loads incurred during repeated knockdowns/capsizings?
    How do you improve your chances of being able to carry on sailing?
    The rig on the boat which Rayman posted, I see that stick breaking off on the first roll.
    Or am I missing something?
     
  12. Manie B
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    Manie B Senior Member

  13. pdwiley
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    pdwiley Senior Member

    Right - that typifies *exactly* my objections to this sort of caper.

    He got in trouble, he triggered an EPIRB and we went and saved his butt. At our expense and at the risk of our SAR people.

    I've said it before but it bears repeating for those who deliberately miss the point - if you want to go and do something like this, either take out insurance against being rescued or go without an EPIRB and take your chances on survival. I don't care which, but pick one. I don't want to stop you going but I think it's foolish and I don't want to pay for the likely rescue.

    What this is doing is basically outsourcing your risk and rescue expenses to someone else who did NOT volunteer for it. The end result is going to be more restrictive rules and more expenses for everyone.

    So Manie, if you want to say try South Africa to Australia in a 10' boat, more power to you, but I do not want to have to pay for the SAR expenses if something goes wrong, OK?

    PDW
     
  14. sharpii2
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    sharpii2 Senior Member

    I think, in your case, with a triple keel design, the lead should be quite short and not include the rudder.

    There are three reasons for this:

    1.) Is the triple keels. The lee most keel will be the deepest when the boat is heeled and will be providing most of the lift. Along with most of the lift comes most of the drag. This increased drag will cause the boat to turn away from the wind, not towards it.

    2.) Is the hull form itself. Essentially what I see here is a symmetrical ended pram. Instead of producing a bow wave, which will be higher on the leeward side, and tend to push the bow upwind, there will be hull surface drag, greater on the leeward side, tending to pull the bow to leeward.

    3.) The height of the rig is relatively modest and its CA is closer to the hull center line, when the boom is let out, due to the balanced lug rig.

    I wouldn't include the rudder, because locking it centered will move the CLA quite far aft, making the boat more stable downwind.
     

  15. Manie B
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    Manie B Senior Member

    sharpii2 - very good points thanks, I like it all, good one.

    pdwiley the boat is not to blame - even if he was on a bigger boat it would have been a problem anyway
    But one thing is for sure - Australia wont see me. We have many friends and family scattered all over OZ and it's not paradise either.
    Australia has bigger problems and DAILY costs with refugees on the water than the odd lonely sailor that might come by every ten years

    BUT he should have avoided OZ because he should have known that they have very strict rules and regulations.
     
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