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.

    60.0%
  2. Probably.

    20.0%
  3. Almost certainly.

    20.0%
  1. sharpii2
    Joined: May 2004
    Posts: 1,905
    Likes: 106, Points: 63, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    Some people find the new foiling AC boats fascinating. I find them somewhat interesting, as they show what can be accomplished with high technology and gobs of money. They go quite fast, maybe in the high 30s to low 40s in knots. Quite incredible for a mono-hull sailboat.

    But Mr. Yrvind's projects fascinate me much more. He seems to be trying to find out how little is needed to make an ocean going sailboat. His boats tend to have little ballast and very short rigs in both aspect ratio and actual sail area.

    This probably has as much to do with practicality as foiling monohulls, which can do nothing but go fast, and only in a narrow range of conditions. But it really gets me.

    He once crossed the Atlantic with a 15 footer which had only 75 sf of sail. And he did it with two people on board.

    Granted, a boat with a ballasted fin keel and a high aspect-ratio rig with generous sail area is certainly faster and arguably more seaworthy. Weatherliness not only wins races, but save one from the clutches of a Lee shore.

    But as limited as his boats are in performance, they do have their vertues. I imagine they are easier to maintain, they can sail in shallower water, and probably have much lower hull and rig stresses. Also, on his latest Ex Lex creation, he can easily step its three masts himself, even when it's in the water.

    Now, the price he ends up paying for these virtues is the interesting part of the story. Will he make it to New Zeeland? Or will he have to give up, like he had to with the first Ex Lex.

    My personal belief is that the original Ex Lex could have been successfully modified, by replacing the two end house structures with a central one, adding another mast and sail, then pushing her harder, which would have meant putting up with a much greater angle of heel.

    But the new Ex Lex is certainly a better boat. It's extra Beam, although not that much extra, seems to have greatly improved its stiffness. It can now carry 6 sm of sail or more. But this still gives it a puny S/D of around 6.0, about what one could expect on a more conventional sailboat which is on its 2nd or 3rd reef. Will this be enough?

    If it is, I find the practical implications interesting. Perhaps motor sailors can be designed with rigs of this class, and sill go vast distances powered by mostly sail, and be a lot easier to keep and look after.
     
  2. trip the light fandango
    Joined: Apr 2018
    Posts: 395
    Likes: 68, Points: 28
    Location: Rhyll Phillip Island Victoria Australia

    trip the light fandango Senior Member

    I looked up Sven after seeing your poll and thoroughly enjoyed reading about his approach to sailing and life. think he has far less chance of being pole axed by a ship at the moment , ..unless it's Saudi oil , he may pass away from old age , but he seems rudely healthy in mind and spirit.
     
  3. bajansailor
    Joined: Oct 2007
    Posts: 952
    Likes: 246, Points: 43, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    Has he set off from Dingle yet?
    The website notes that he was planning on leaving in June 2018.
    Exlex https://www.yrvind.com/videophoto/exlex/

    And that he anticipates possibly taking 167 days to sail from Argentina to Australia in that little boat. Yikes!
     
  4. Will Gilmore
    Joined: Aug 2017
    Posts: 102
    Likes: 21, Points: 18
    Location: Littleton, nh

    Will Gilmore Senior Member

    I was following Sven for a time when I first found out about the AiT challenge. It's part of what prompted me to join this forum. That whole concept has captivated me because it speaks to independence and doing things with little or no resources.

    I love what he's doing and his reasoning around the virtues of smaller craft taking less stresses than larger craft make perfect sense. I haven't tuned into his website for a while, but I will vote for his making his destination, but not on his expected timeline.

    I'm also not a fan of his design choices, but they work for him.

    -Will (Dragonfly)
     
  5. Waterwitch
    Joined: Oct 2012
    Posts: 98
    Likes: 13, Points: 8, Legacy Rep: 20
    Location: North East USA

    Waterwitch Junior Member

    I wonder if he is really sailing or more drifting with the prevailing winds and currents. After all coconuts from the Caribbean wash up on the shores in Ireland. Big logs from Oregon end up on the beaches in Hawaii. Thor Heyerdahl managed to crash land his raft near Tahiti. The Pacific voyagers set off from Taiwan found and inhabited every known island in the south Pacific they even stoped in South America and brought back people with them to Easter Island. They traveled in long lean double canoes and proas though
     
  6. Will Gilmore
    Joined: Aug 2017
    Posts: 102
    Likes: 21, Points: 18
    Location: Littleton, nh

    Will Gilmore Senior Member

  7. bajansailor
    Joined: Oct 2007
    Posts: 952
    Likes: 246, Points: 43, Legacy Rep: 37
    Location: Barbados

    bajansailor Marine Surveyor

    I wonder how long he has been moored in Funchal, Madeira?
    I admire his patience, sailing at an average speed of 2 knots, or less.
    I can think of better things to do in life.
    'It is still a LONG way down to Argentina, and he has to get through the doldrums as well.
     
  8. sharpii2
    Joined: May 2004
    Posts: 1,905
    Likes: 106, Points: 63, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    What you're watching is an earlier adventure on his first Ex Lex. The new Ex Lex sails much better. He has given it rather thorough sea trials this time. As far as I know, he hasn't left yet.
     
  9. sharpii2
    Joined: May 2004
    Posts: 1,905
    Likes: 106, Points: 63, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    I have been watching his progress tracker.

    It seems he is having a hard time getting to windward. His plan was to go around the north of the UK to avoid the hectic sea lanes. But now it seems the weather conditions just won't let him.

    Having seen his sea trials, the boat seemed to perform well enough. It seemed to be sailing well over 2 kts, maybe 3 or even 3.5. I have been trying to figure out why the boat seems to be performing so poorly now.

    The best explanation I have been able to come up with is that his S/D was much higher when he did his sea trials than what it is now.

    Let me explain.

    He said that the boat itself came out to be about 600 kilos. I'll assume this included the rig.
    He and a friend sailed it, so I'll add 150 kilos to account for that. This gives us a total of 750 kilos. Since we are measuring the Sail Area in square meters, we must measure the displacement in cubic meters. So we end up with a displacement of 0.750 cubic meters (750 kilos/1,000 kilos per cubic meter). 0.750 to the 0.667 power = O. 825. The Sail Area of 4.0 sm/0.825 = an S/D of 4.85.

    Now let's see what happens when he loads it up with gear.

    He said his departure displacement was going to around 1,200 kilos. This makes good sense. He probably added about 500 kilos, which is about 1,100 lbs. 1,200 kilos = 1.20 cubic meters. 1.20 to the 0.667 power is about 1.13. 4.0 sm/1.13 = an S/D of just 3.54. Maybe this explains why he seems to be making such miserable progress compared to how well the boat seemed to do in sea trials.

    He does have a third sail of what I think he said was about 1.80 sm. If he were to add this (maybe he has) he would then have 5.80 sm. This would get him back yo were he was during sea trials (5.80/1.13 = an S/D of 5.13).

    But this does not tell the whole story. The boat he sailed during sea trials was a two masted schooner. The one he'd be sailing with the third sail added would be a three masted one.

    Schooners already pay a price in windward performance with just two masts. Adding a third one increases this penalty. This is because each sail must be put at a greater angle to the wind than the one before it, if it is to contribute any significant amount of drive.

    This means the boat has to point further off the wind until the last sail has sufficient angle to produce drive. This may mean 120 degree tacks or more (and probably more). This means probably less than 1.0 m of windward progress for about every 2.0 m sailed. IFIRC, the world's record for number of masts on a schooner was seven. And that did not work out well.

    I will stay tuned to see what happens.
     
  10. upchurchmr
    Joined: Feb 2011
    Posts: 2,965
    Likes: 119, Points: 63, Legacy Rep: 579
    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    Sharpi2,

    Nice analysis.
    I can't understand why this boat empty weighs 600KG.
    This whole thing is going to have so much wind drag in the hull compared to what the sails develop as drive, that I think your analysis is going to be optimistic. Especially in going to windward.
    So much is known about boat design that could have made a better boat.
     

  11. sharpii2
    Joined: May 2004
    Posts: 1,905
    Likes: 106, Points: 63, Legacy Rep: 611
    Location: Michigan, USA

    sharpii2 Senior Member

    I don't find the 600 kg boat weight all that startling. This weight includes ballast, which he has installed externally in the form of a huge slab of bronze (I wish I had his kind of money), some hefty batteries, and I believe his ground tackle. Also, although he used foam/GRP construction, his hull is about two inches thick. His choice of this type of construction is more about insulation properties than weight saving ones.

    A design of mine, which is in the same class, (though not made of expensive composite materials) will likely tip the scales at about 750 kg (with ballast) upon launching, and about 1300, upon departure. But it will have about 14 sm of sail for an S/D more than three times as great as Sven is using.

    Limited draft and limited ballast along with the requirement of a good range of stability, has kept the rig relatively small.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.