Reefing a lanteen sail

Discussion in 'Sailboats' started by science abuse, Aug 23, 2011.

  1. BATAAN
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    BATAAN Senior Member

    More sources for Lateen research.
    Reefing the foresail and detail with brass-balled mariners.
    A couple of lateen merchantmen and
    a battle showing yards slung outside the shrouds.
     

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  2. sharpii2
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    sharpii2 Senior Member

    Thanks, Bataan.

    I'm looking at the guy lines on the upper yard. They must have had two sets. One on each side.

    I also see that the shrouds were held with block and tackle arrangements, which would be easy to removed to put the yard outside the shrouds, or inside.

    Unfortunately, artists are not engineers (at least not usually), so except for the really broad strokes, such as the yard being outside the shrouds and the men on the yard, hand reefing the sail, there seems little we can take on authority.

    I think we can count on artists of that time to paint what they actually see, but their lack of expertise on how the mechanical systems worked could be a real handicap.

    What's really interesting about theses paintings is there doesn't seem to be enough room to dip the yard. The yards seem to hang at such an oblique angle that the lower tip of it would hit the deck long before it could be brought behind the mast. I suppose the artist either painted it slung too low, or the whole yard could be hoisted higher to get more room.

    Back to my 10ft model.

    If the yard could be dipped , or stood on end an flopped past the mast onto the other side, the yard length could be increased by as much as 50%, conceivably adding that much more sail area. This would not hurt the sheeting angle one bit. Most likely, it would be increased by 20 to 30%. The trade off would be more sail area for less control-ability.

    I suppose the next step would be to add sail area beneath the heel of the yard, so the yard could be dipped without raising it. Then you have a settee, but it never seems to have caught on. At least not in the Christian world.

    I suppose we could start a good fight in claiming the dipping lug evolved from the lateen sail, rather than the square sail.

    To your knowledge, did the vikings ever set their square sails as fore and aft rigs?
     
  3. BATAAN
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    BATAAN Senior Member

    Those drawings above from Album du Levant of 1679 by Jean Jouve (Musee de la Marine, Paris), other than the battle picture, were subject to minute scrutiny by contemporary mariners intimately familiar with the tech to a level we cannot imagine today, and were an official record of shipping, so are not fanciful or inaccurate, but a very true picture of sail proportions and rig details, or would not make it into official publication at the time, but it seems since it is not understood today, it is wrong.
    Some artistic interpretations are of course very bogus, but these I chose because they are quite accurate. It's like an artist today getting the wings and engines on a jetliner out of proportion or position, everyone knows how it's supposed to be and would ridicule him.
    The 'guy lines' are vangs.
    Here's more reference material from the above source and some from Jean Baugean, famous for his accuracy and minute attention to nautical detail of things he could examine closely and was around every day.
    We don't have to be an engineer to draw a face perfectly, but an artist, neither do these particular artists have to be engineers to draw these ships. They don't sketch in ropes and stuff because it looks good, but because that is what they see, where they see it, for customers who are marine professionals who won't buy it if it's wrong. This is pre-photography and this style of recording was quite developed.
    Of course Vikings set their sails fore and aft, they were not stupid, but fabulous sailors. How the hell else did they get back from Greenland?
    Look at these Viking ships (10 second google search) hard on the wind (yes square rig goes to windward) and see you only have to pull the yard down a little forward and it's a lug sail.
    And I've included a first hand description of being 'on the wind' at sea in a huge open boat so we can feel the cold water coming over.
    And since all this was worked out a zillion years ago, why are you spending so much time on reinventing the square wheel instead of researching "round" theory? Just learn from those who died making mistakes while figuring it out and do your research. All the below took me 15 minutes to find and post.
     

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  4. gilberj
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    gilberj Junior Member

    You might want to look at the Racing Dhows off Abu Dhabi, and Dubai to see how they do it. You might also want to look into some of the Columbus vessels Nina, Pinta, versions to see what they did. Tim Severin did the Sinbad voyage using a large cargo type dhow.
    My own reefing with a boom was tasking about 30% wedge out of the sail. This seemed to work reasonably well, though I reefed with the sail down as it was a really small boat.
     
  5. Pericles
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    Pericles Senior Member

  6. BATAAN
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    BATAAN Senior Member

  7. science abuse
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    science abuse Junior Member

    Looks stout and simple to sail... on a few points of sail, anyways. How do you run with that rig? It seems as though things would bind in the... umm, A-Frame spars? What does one call those masts? I imagine the forestay is still called a forestay, no matter what it's made of.
     
  8. sharpii2
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    sharpii2 Senior Member

    Hi, Science.

    Just looked at the web site.

    Apparently, they are using a tripod mast. The yard is at a vertical enough angle to clear the the forward leg of this tripod.

    As a tripod, it needs no stays or shrouds.
    An interesting design.

    I would like to see how they reef.

    My guess is they reef from the bottom up, so the yard can keep its angle and not foul the forward leg. The boom would have to cock up, but in rough seas, that's not such a bad thing.
     
  9. sharpii2
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    sharpii2 Senior Member

    Flying lateen revisited

    Oops!

    Just checked the site out again. They have another gallery linked to the word 'fly'. Found out how they reef.

    The sail roller furls to the yard in a parallel fashion.

    I never thought something like this could work with a boomed lateen, but, when reefed, the clew is let out from the boom, leaving the boom/yard geometry unchanged.

    It never occurred to me that a boomed lateen could be lose footed.

    Very clever.
     
  10. sharpii2
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    sharpii2 Senior Member

    Wow. I never knew you could brace a yard that far forward. Maybe the bow lines take a good deal of the strain. It would seem to me that the windward brace would be at such a fine angle that the strain on the lines would be unacceptable and they would stretch, particularly in a sudden gust. My bad.

    What I meant by 'setting up as a fore and aft rig' is leading the windward braces to the bow and, perhaps, setting the yard and sail inside the shrouds.

    From this picture, I can see it seems to be working quite well as originally rigged (as a square rig, not a fore an aft rig, the leech still becomes the luff when changing tacks).

    I checked out the other links you posted.

    Huge confusion.

    Apparently, based on earlier links, the lateen rig was superior to the square rig in going to windward. Then, from another link, the square rig was better than the lateen in doing that, by the end of the middle ages.

    Could this be because of better fabrics?

    I know the lateen rig has a reputation for being able to work with not so good fabrics. I imagine bow lines must put a considerable strain on the fabric.

    Did the vikings have access to better fabric than the Eastern Europeans?
     
  11. Pericles
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    Pericles Senior Member

    sharpii2 wrote

    "Did the vikings have access to better fabric than the Eastern Europeans?"

    Which is better, fleece or flax? There's part of your answer. Look up the rest. It's very easy.
     
  12. BATAAN
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    BATAAN Senior Member

    Difference between a square sail and fore and aft is square sail always has the wind on the back side, even hard on the wind. Fore and aft has the wind alternately on one side and then the other. Most historians accept that the lugsail developed from the simple square sail. Here's a replica of a 2nd century BCE Greek merchantman in a strong wind and lumpy sea and some miscellaneous info on trad F & A rigs.
    Also see the following, especially the first one which is long, historic and technical and will take a while to digest:
    http://soton.academia.edu/JulianWhi..._The_invention_of_the_lateen_sail._Volume_One
    http://nabataea.net/sailing.html
    http://www.amazon.com/Development-Lateen-Sail-entry-Science/dp/B0027UWMFC
    http://www.bookrags.com/research/development-of-the-lateen-sail-scit-0212345/
    http://forum.woodenboat.com/showthread.php?99406-Lateen-sail.-s
     

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  13. Angélique
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    Angélique aka Angel (only by name)

    [​IMG]

    Hi, here a lateen with roller reefing system...

    I posted it in the thread ‘‘A-Frame Mast’’, for details see post #15 and beyond . . . .

    Cheers,
    Angel
     
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  14. sharpii2
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    sharpii2 Senior Member

    Thanks, Bataan.

    The arguments that the lateen sail evolved from a square sail seem quite credible. The bit about the Red Sea being the point of origin seems quite convincing, once the nature of the winds in that neighborhood are considered.
     

  15. Pericles
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    Pericles Senior Member

    Angélique,

    Thank you for that very interesting link. It's an ingenious solution that requires modern materials and components to work. There's many a good tune to be played on an old musical instrument. ;)

    Regards,

    Perry
     
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