around in pocket, I I think so

Discussion in 'Projects & Proposals' started by WindRaf, Oct 2, 2014.

  1. Westel
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    Westel Senior Member

  2. WindRaf
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    WindRaf Senior Member

    the difference is that here a child after two years of school knows how to read and how to write, and to you after ten years are still learn spelling...and many adults dont know to do it better even at forty years;
    and do not exist, as my imperfect experince in english, words gentle, but forms to build the frase in good form;
    so the commedia dell'arte has a very good advantage :D
     
  3. Westel
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    Westel Senior Member

    You're right, my English is very poor and even at age 60 I'm still learning .....mea culpa.

    I dont know what is "better", think that you can learn a lot from others or think that others can learn a lot from you......hmmmm....;);)
    I clearly belong to the first group (or I wish to believe this) and you obviously belong to the latter group.
    As long as we both feel happy it's OK I guess.

    Keep the wind blowing Windraf.....:D
     
  4. WindRaf
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    WindRaf Senior Member

    the wind blowing is not offensive, dear friend :D
     
  5. sharpii2
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    sharpii2 Senior Member

    I agree. It has often been called a "******* tongue". Spelling gives me fits, as the spelling of every word has to be remembered.
     
  6. sharpii2
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    sharpii2 Senior Member

    OK.

    I see.

    I suppose the bulb really doesn't cause much trouble, other than making the boat more complicated to build. It may improve performance, but I have read such improvements are in the low percents, such as 4%.

    I just don't see that tiny advantage as worth the trouble.

    What I don't get is why you want to go with the "V" sectioned keel.

    It too will complicate construction without providing any advantage that I can see.

    Perhaps the idea is to reduce whetted surface.

    But the sides sloped toward the bottom will help more water pressure from the down wind side sneak under the keel, reducing its effectiveness.

    I hope you show us some more drawings of the rig and explain how it will work.
     
  7. sharpii2
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    sharpii2 Senior Member

    Just to see what it would look like, I went ahead and sketched the rig I described for DECAS MAXIMUS.
    (See attachment)
    So this is what a sailing buoy might look like.

    What seems like a huge amount of sail, is really a quite modest sail plan for this displacement.

    I'm just curious on just how far the limits can be pushed.

    As drawn, the main alone might produce severe weather helm, as its Center of Area (CA) is aft the hull's Center of Lateral Area (CLA).

    This might be true of more conventionally proportioned hulls with this kind of rig.

    But this one has a very tight turn in its above chine waterline, near the Beam end, which might cause significant drag there, causing the boat to want to turn down wind. Having negative lead might counteract that.

    Who knows.

    I'm thinking of making a small model, just to see how it sails. I'm thinking of making it one foot (30.5 cm) long. It would weigh almost five pounds (2.27 kg)!
     

    Attached Files:

  8. WindRaf
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    WindRaf Senior Member

    A boat so small and heavy, can only do displacement speed, so every inch of waterline length must be used.
    The bottom V and the V shaped keel serve to have the prismatic coefficient low even with large beam.
     
  9. sharpii2
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    sharpii2 Senior Member

    Making a vertical sided keel which is half as wide as the top of your "V" sectioned one, will not change the Prismatic Coefficient that much if at all.

    If you keep the same airfoil top view, but half as wide, its horizontal center of buoyancy will be close to that of the Hull.

    Having the keel slope upward to the waterline, making it 10 ft long, then adding a vertical piece, which would extend up to the top bow transom, would maintain your 10 ft WL.

    It would also eliminate a handy place for floating kelp, fishing line, and other marine junk to get caught in.

    It would allow placing the ballast somewhat lower too. And it would make the keel a whole lot easier to fabricate.
     
  10. Jamie Kennedy
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    Jamie Kennedy Senior Member

    I think the bulbous bow is a fun idea to play with, especially for a such a high displacement and wide boat. In theory it doesn't just move the bow wave forward. It creates a second bow wave that does a little destructive interference with the other. Of course the proof is always in the pudding. It should be relatively easy to experiment with different bulbs and with no bulb. It may also help directional stability.
     
  11. Westel
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    Westel Senior Member

    Wonder if the minimalist speed is functional enough to make such a bulb "perform".
    I think, if made in the steel version, that the work/cost doesn't match the benefit......but I'm not an engineer.
    The "hook type bulb" might be not the best shape to avoid catching unwanted balast ( seaweed ?) .
     
  12. Manie B
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    Manie B Senior Member

    It would be very interesting to see the Freeship values published, they tell you a remarkable lot. On my Fargo they were accurate enough, so much so that I am confident about my Ten hull design. Such a small boat at such low speeds and nothing matters as much as one would think. For me it is just nice to know that it gave me a theoretical speed of 4.2 knots with a resistance of 500 watts. In other words to push the Ten along at 3 knots does not take massive power. We are hoping for 70 nm per day under ideal conditions which Gerry Spies got and I think his best was over a 100 nm / day.
     
  13. Angélique
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    Angélique aka Angel (only by name)

    I see only gains in Sharpii2's above solutions. It also provides the option for a thick steel keel sole as ballast instead of fixed internal lead ballast. If chosen for this, I still would reserve some weight for trim ballast though.
     
  14. WindRaf
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    WindRaf Senior Member

    Manie,
    you are right.
    3 knots are displacement speed
    2 knots the ocean current
    total 5 knots.
    ( i can not untestand why someone he said he crossed the Atlantic to two knots when in that route the speed of the current is 2 knots ...)
    Anyway, the problem is have the maximum displacement speed also with light winds.
    This is the first idea about my designe steel ten.
     

  15. Angélique
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    Angélique aka Angel (only by name)

    Maybe you could try to add a kite for light winds. Problem with this though is that with very light winds the kite won't get up or drops in the sea al the time, also storage and handling on a TEN could be a problem. But maybe it's worth a test . . . ? ?

    Here's an example, just for the kite, but these are not light airs . . .​

    P.S. - - - - More info about the video can be found at: KiteTender
     
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