AIT Around In Ten

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

  1. GTO
    Joined: Jul 2007
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    GTO Senior Member

    Manie,

    Have you tried to find any information on Yankee Girl?
    Seems to me that boat would be the baseline for a 10 footer, given the success Gerry Spiess achieved. Just an opinion though.

    Yankee Girl
     
  2. MoeJoe
    Joined: Apr 2012
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    MoeJoe Junior Member

    I'm guessing a bit, but it could partially be related to be able to prepare the boat for extreme conditions with very big waves and high wind speeds where you have to run downwind.

    -If you have a deep keel and a fixed rudder, on a very short (and wide) boat like a AIT or sub-15 feet boat, I can imagine that the risk of getting sideways (broaching) to big waves is increased as there is less directional stability. If you can pull up the daggerboard, boat will be more stable downwind. And would probably "slide" sideways down a wave rather than tripping over the keel if it was deep and fixed.

    Perhaps.. :?:

    ..Other additional reasons could of course be ability to beach the boat, making it easy to get on a trailer, and for getting the boat self-steering under various conditions together with the sail rig and adjustable rudder angles.
     
  3. Manie B
    Joined: Sep 2006
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    Manie B Senior Member

    Quote from Yankee Girl

     
  4. Angélique
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    Angélique aka Angel (only by name)

    Sven tells about the bow centerboard in his post on May 17, 2008:
    The 15' boat from above quote is described in Sven's post on June 16, 2008:
     
  5. GTO
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    GTO Senior Member

    Manie,

    Do you have enough information to model Yankee Girl?
    I'm amazed the boat had such a modest keel area yet seem to perform well.
    It would be interesting to see some numbers characterizing the hull.

    Angelique,
    I have a friend that runs ultra marathons (30 - 100+ miles).
    People like Sven and my friend just seem to accomplish what would put off or even kill the rest of us. :)
     
  6. Angélique
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    Angélique aka Angel (only by name)

    Some info here, specs in the 3th pic . . .

    _Yankee_Girl_book_.jpg - _Yankee_Girl_sketch_.jpg - _Yankee_Girl_specs_.jpg
    - - click pics to enlarge

    More info in the book I guess . . . :idea:

    P.S.

    Just saw you posted above link in post #76, so had seen these specs already . . . ? ? ?
     
  7. GTO
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    GTO Senior Member

    Yes Angelique,

    I actually have an autographed copy of that book, which I found on Amazon.
    I was wondering if Manie could produce an accurate enough model to determine Yankee Girl's stability graph, centers of effort and resistance, keel area - that sort of thing.

    I'm just curious as to just how much of a "boat" a ten foot, 2000+ lb. design can be, as oppose to just a tub which is blown more or less in the wind's direction. With Yankee Girl there is some data available (as you pointed out) that allows a (limited?) comparison of modeling results to real-world experience.

    Thanks for helping.
     
  8. Manie B
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    Manie B Senior Member

    With the limited info that is available on Yankee Girl it hard to tell why and what works well.
    My thinking was to read what I could and make some sense from the "stories" that are told about her handling.

    I am drawing my ideas and inspiration for my design from 4 main sources
    Sven Yrvind
    Roger Taylor
    Yankee Girl
    Matt Leyden
    These are my primary "feeders" but I also have read hundreds of pages of all the small boat sailors over the ages, starting with "The Dove" some 40 years ago.

    So the conclusion that I am stuck with at the moment is a full keel and bilge keels to ensure directional stability to ensure the ability to point, I am hoping for 90 degrees tacking. The full keel also supports a very strong rudder with inside steering.

    The main issue here is that as my "Fargo" is nearing completion we will have an active platform to verify our previous calculations. this of course will go a long way towards helping to eliminate some doubts of the "Ten"
    I will also test my 'ten sail' on Fargo.

    So anyway lots of back and fro, questions after question, what about this and what about that, who knows.
    Fargo should be completed by End April 2014
    AND THEN work starts on the TEN
    I am planning on ;) laying the ten keel before end may ;)

    hold thumbs :D
     
  9. Manie B
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    Manie B Senior Member

    Question to all

    Open Question on Keel

    Folks I would like to hear a bit more of your own feelings and perceptions regarding the "Full Keel" story on a small 3m heavy displacement boat.

    So in your experience have you ever been in a situation where the boat "tripped" over it's keel? What were the conditions and where?

    I would rather have directional stability for good tacking - hence the full keel as preferred by Roger Taylor - what are your thoughts on this?
     
  10. Manie B
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    Manie B Senior Member

    Oh and I must add HUGE inspiration from SCAMP with it's lugsail
     

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  11. Tad
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    Tad Boat Designer

    Another important reference should be Robert Manry's voyage in the 13' Tinkerbell. Trans-Atlantic in a modified open daysailor in 1965. He took 78 days for the crossing, but I remember being stunned when I read he stopped at night and lay to a sea anchor. Of course he had no self-steering of any kind, and probably no electricity at all......

    http://www.clevelandmemory.org/ebooks/tinkerbelle/tinkchap5.html
     
  12. Manie B
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    Manie B Senior Member

    Sven Yrvind

    Hello Sven,

    Thank you for your kind words and advice.
    ;) And no, I am not even close to be any kind of competition for you ;)
    As you know by now I am one of your BIG FANS and supporters.

    I am a strong believer and supporter of small yachts and because I feel as strongly about this subject as you do, I felt obliged to put my mind and energies into such a project as support for this challenge for the whole world to see.

    My present boat is virtually complete and I will start building my new "TEN" beginning May. My "Fargo" will have a permanent mooring at our Vaaldam and then my "workshop" is open for the next project. I am really looking forward to building a "TEN" it is a huge undertaking as a ten foot ocean going yacht is a hell of a lot more than just a boat. It is hundreds of hours of reading and research. To me it is a challenge of mind body and soul.

    I have taken note of your ideas on the keel and after many hours of reading I am reasonably sure that this could be my final design. I also show my swim platform :D

    http://www.yrvind.com/present_project/

    Once again many thanks for your support Sven
    Regards
    Manie
     

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  13. Manie B
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    Manie B Senior Member

  14. sharpii2
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    sharpii2 Senior Member

    Hi Manie.

    Glad to see you have taken such an interest in the AIT concept. Too bad this wasn't in the "Sailboats" section where I think it belongs. I found it only from a reference on Sven's web page.

    Your hull design is interesting, but I think she is a tad bit narrow at the hips.

    This causes three problems:

    1.) a wider water plane capsized than when upright, perhaps making the boat stable when inverted,
    2.) less storage space low in the hull, forcing storage higher up, and
    3.) less initial stability for sail carrying ability.

    Other than that, it looks like you have borrowed a lot of Sven's ideas. No problem with that.

    Sven is fiendishly clever. I have been following him since his BRIS I - V days.

    I find Sven's rig ideas a bit troubling.

    If his boat is capsized with the sail(s) up, I think there is little chance of the unstayed masts surviving the ordeal.

    I will say, though, that with the 'board' retracted, which it will probably be, during most of the voyage, the boat will be very hard to flip indeed. It will be like a margarine tub that is half full. It has no corners to grip the water and is more likely to be driven before a wave than it is to be flipped by one.

    I am sure he is betting heavy on that.

    Too heavily, IMHO. But he's the master; I'm the student.

    It looks like you are making a similar bet. If so, here's another reason to make her wider at the hips:

    The angle of the deck to topside will be less acute. This will make it less likely to dig in and flip the boat.

    Sven is a bit critical of your long keel. He thinks it will cause more harm than good. It appears more likely to trip the boat than to stabilize its course. He may be right about that.

    However. Below. For everyone's entertainment, I'll post my own AIT concept:

    FOOTBALL An AIT Boat

    This design concept is meant to satisfy the rules of a proposed race around the world in ten foot long sailboats.

    The major goals here are strength, simplicity, and easy handling.

    The hull form chosen is a double ended pram. This is to insure good course keeping even when the boat is over driven. This hull form also provides a great deal buoyancy above the waterline. This, along with high sides helps to prevent water coming on board in high seas.

    The stern transom is submerged several inches when the boat is fully loaded. This is to help prevent broaching, as the boat will be sailed mostly down wind. It also helps to provide a more gentle aft run, after the boat is lightened by consumed stores. This may improve its speed in later stages of its hops.

    The full length, fin keel is to steady the boat, help keep it on course, and to insure it self rights, if capsized. Its specific gravity is actually meant to be quite low (about 2.0, or less), so it subtracts little from boat’s carrying capacity, while adding considerably to its ultimate stability.

    As can be seen, the hull is divided into many compartments. These are meant to store a mountain of gear and stores. Such are prioritized by weight, with the heaviest stowed low and the lightest stowed high. With everything reasonably corralled, finding a needed item should be quite quick and maybe even more pleasant than on a larger boat.

    This boat is designed to be worked from below, with the skipper never coming on deck.
    The diminutive size of the boat, its high sides, and the relative weight of the skipper makes this a must, IMHO.

    The sail rig is probably my only innovation (most of the ideas were lifted from YANKEE GIRL).

    It is balanced to provide an extreme lee helm with the jib up. This is to make sure the boat tracks well on its most typical point of sail, a down wind tack. It will never be sailed dead down wind. The hope is, with this set up, no expensive and vulnerable self steering gear will be needed.

    With the jib struck, a balanced helm is restored, so the boat can reach and sail upwind reasonably well. The gaff rigged main insures the balance remains quite close even with the main severely reefed. The mast is held up by its partners and reinforced with three heavy stays (probably 0.25 inch , 7x49 cable). This is to help insure the mast stays in the boat, if (and probably when) the boat capsized and, or pitch poled. The diminutive size of the rig is mainly to insure its survivability.

    Studding sticks and a bowsprit extension could be added for light wind sailing. The studding sticks add a strip to the mainsail, and the bowsprit extension adds an outer jib.

    Both of these light air sails will be flat cut and easy to stow.
     

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  15. Manie B
    Joined: Sep 2006
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    Manie B Senior Member

    Well this got me thinking :?:

    and I decided to give it a try and see what happens


    UNBELIEVABLE

    CHECK THE VIDEO IT SELF RIGHTS IN UNDER ONE SECOND

    http://www.youtube.com/watch?v=R3ZxPMVGsas

    I basically weighted the tub down to the same kind of depth that my AIT would be fully loaded
     

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