Why I'm Following Sven Yrvind

Discussion in 'Sailboats' started by sharpii2, May 7, 2020.

?

Do you believe Sven's latest Ex Lex will make it to New Zeeland.

  1. Nope.

    50.0%
  2. Probably.

    30.0%
  3. Almost certainly.

    20.0%
  1. JPE
    Joined: Aug 2019
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    JPE Junior Member

    Yep. Boats with flared sides (the 99% of production sailboats) can handle varying load with less hassle.

    For a boat designed to sail long trips, like, hmmm , say Ireland to NZ this should be desirable.
     
  2. A II
    Joined: Jun 2020
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    A II no senior member → youtu.be/oNjQXmoxiQ8 → I wish

    No yep, in post #120 I've just explained it's no hassle, which production era are you referring to ?
     
  3. JPE
    Joined: Aug 2019
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    JPE Junior Member

    Boats of the same era as the Exlex series, if that was not obvious for some. And actually, sailboats of pretty much any era hardly have sides that are dead straight from the waterline up. You will, no doubt, present us with a plethora of such boats. I anxiously wait for seeing your comprehensive list of successful straighsided sailboats, I really do.

    So, you claim that Svens boat was able to take the extra load with no problems, or what do you mean there is no hassle. You are correct in the sense that in it's current setup the progress of Exlex is quite peacefull, so no hassle there...

    If it had flared sides, it would have been able to carry the load with less immersion. All in all, the most basic mistake Sven has made in his design choises is to make the boat too damn small for his extended range voyage plans. He further complicated the dilemma by making the sides straight, as there will be no extra flotation as the boat sinks deeper.

    Oh, and: which boat with straight sides are you referring to? Exlex does have major problems with added load.
     
  4. A II
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    A II no senior member → youtu.be/oNjQXmoxiQ8 → I wish

    JPE, you like to make something different from what has been said, I don't feel like reacting to that.
     
  5. A II
    Joined: Jun 2020
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    A II no senior member → youtu.be/oNjQXmoxiQ8 → I wish

    Just remembered Sven also replied many times on his website to the OP of this thread, below some examples from just 2014, for a quick find of it check the linked example pages for Sharpii.

    March 18, 2014 - Mast Strenght


    June 10, 2014 - Clarifying Next Boat

    Aug. 21, 2014 - Faster Horses (response to post #405)

    Aug. 28, 2014 - More About My Strong Rig
     
    Last edited: Aug 15, 2020
  6. KeithO
    Joined: Jul 2019
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    Location: Michigan

    KeithO Senior Member

    Examples of straight sided boats/ships would be any bulk/oil/container vessel. Of course they are not sailing vessels and use some of the largest ships engines ever made. And WLL on those vessels is obviously very long which is why they have higher hull speeds... So not really applicable in this discussion... I think the drag of his boat probably goes up very fast as it is more immersed because of its bluff bow configuration. I dont recall the stern configuration well enough to know if additional suction is generated there as immersion increases but that is also possible. One wonders if he would do better if he had to put his extra stores into barrels and tow them behind in a dingy ? He is going so slow I wouldnt be worried about hull speed of the dingy.
     
  7. JPE
    Joined: Aug 2019
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    JPE Junior Member

    Good point on the bow shape. Spoon bows do have benefits, I recall Sven discussing these on his site, and he wold not have constructed one if it was not a proven concept in some sense.

    A couple of things about spoon bow slipped his mind, however:
    • One mostly sees them on wide racing boats, I do not recall a singlel successful implementation on a narrow, straightsided dailboats.
    • The absolute requirement for spoon bow to worl as it is intended is that it must not get immersed under any conditions
    I'll give points to Sven for testing this bow shape on Exlex, but as I have stated in posts # x y and z, he failed miserably in his mass calculations, making the bow work against him. It may very well be the bow is a major contributor to the poor pointing ability of the vessel.
     
  8. JPE
    Joined: Aug 2019
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    JPE Junior Member

    I did no such thing, but I accept your retreat.
     
  9. A II
    Joined: Jun 2020
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    A II no senior member → youtu.be/oNjQXmoxiQ8 → I wish

    From your very first post on these forums you did so (thread Yrvind post #604), and then in many of your subsequent posts.
    It's just to tiresome to straighten it all out like I did (on the thread Yrvind in post #605 and the following), in the replies to your first series of posts.
     
    Last edited: Aug 15, 2020
  10. KeithO
    Joined: Jul 2019
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    Location: Michigan

    KeithO Senior Member

  11. A II
    Joined: Jun 2020
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    A II no senior member → youtu.be/oNjQXmoxiQ8 → I wish

    Keith, both pics are of ExLex I, Sven is now at sea with ExLex II.

    June 23, 2020 - I will start soon

    [​IMG]
     
  12. KeithO
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    KeithO Senior Member

    Dang, confusing site to navigate..... Shape of the stern seems to be the same, if more deeply immersed would create a drag problem. Now I no longer have acsuitable picture of it squatting for reference.
     
  13. JPE
    Joined: Aug 2019
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    Location: Finland

    JPE Junior Member

    Regarding my earlier posts, A II you are totally correct.

    As for the transom, in test sail videos the boat seemed quite balaced, perhaps a little tail heavy. I do not recall if Sven declader the mass of the boat during test sails, but there certainly was not much margin to add it.

    With the Exlex Minor now apparently sitting quite low, the bow and the stern are both braking very efficiently.

    It might be, that the spoon bow is, as opposed to a more traditional design, a little unstable, and as the stern is quite narrow but still wide relative to the hull, and submerged (?), it may produce vortex shedding, making steering very difficult. This is of course guesswork, as I'm more familiar with aero- than hydrodynamics.


    P.S.
    A wise man was once asked about the secret to a happy life. Without hesitation he replied: "Do not argue with fools!"
     
  14. A II
    Joined: Jun 2020
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    A II no senior member → youtu.be/oNjQXmoxiQ8 → I wish

    Correct, hence I've said in post #124: ‘‘ I don't feel like reacting to that ’’
     
    Last edited: Aug 15, 2020

  15. JPE
    Joined: Aug 2019
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    JPE Junior Member

    Last edited: Aug 15, 2020
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