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Split Junk, Cambered panel or hinged batten sail. Which to choose?

  • 07 Dec 2012 18:43
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    Reply # 1154596 on 746824
    Anonymous member
    Hi Arne

    Well, there isn't one, really.  And I'm still tweaking.  Essentially, standard YHP, a luff hauling parrel and one standing luff parrel.  I'll post a photo on the photogallery which shows the set up of the LHP.  Still working on getting the boom set just as I want it.  Of course, I haven't had a chance to sail the boat for 3 months (!) what with caring for my friend and then hauling out.
  • 07 Dec 2012 18:42
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    Reply # 1154595 on 746824
    Anonymous member
    Annie is working hard on her boat, and I'm not, so here is what she heard from Alan:

    Hi Annie, we've done 3 days sailing, v light winds to about F5 for a short time but v gusty. The difference is spectacular re speed, but we've more to learn about tacking angle. We have to sheet the main in much more and the wind hasn't been consistent enough to properly measure the angle we tack thru.. We certainly make to weather faster, and we no longer miss stays. We tacked all the way into Chaguaramas up to Powerboats fuel dock. The throat parrel takes most of the strain off the Hong Kong Parells. There are no big creases, but we may have overcooked the slackness of the sails (we made the sails 152 inches for 150 inch battens with about half inch to the holes ie it's about 149 inches from hole to hole, so the sails are 3 inches wider. Hope this makes sense). They still look fine. Also we did the main bolt rope a bit tight, but as soon as there's any wind ( F1/2), the cloth is fine. The foresail is about right. We need more consistent conditions to really tell, but they work! El Lobo took a load of photos and we'll get those sorted. We also took photos showing the camber (and the sail making process). 

    These are the figures Slieve provided me with to get the curve right. He's suggested they get published with the sail making article. Hope this all makes sense. The figures in inches are; the panel width is 47 ", chord is 150",  max camber is 2 x 7.5", 1 " seams top and bottom. ie 47"+7.5"+7.5"+1"+1" = 64"  .   ie the Odyssey III was just wide enough for 10% camber.

     I followed Arne's ideas to the letter. The battens are in full pockets, each 35 inches long, touching each other. We rigged a throat parrel (yard to batten no2) and Hong Kong parrels. We haven't had a problem with bad creases, although the main triangle panels will need a look at. We intend to sail to Grenada on Saturday, so we'll see how it all goes! 



    All the very best,  Alan
  • 07 Dec 2012 18:20
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    Reply # 1154581 on 1154540
    Anonymous member (Administrator)
    Annie Hill wrote:Fantail's mast is raked forward at 6 degrees and I have no problem with batten stagger!


    Annie, where do I find  a diagram or list showing which control lines, fixed and running, you use on Fantail's sail?

    Arne
  • 07 Dec 2012 17:42
    Quote
    Reply # 1154540 on 746824
    Anonymous member
    Fantail's mast is raked forward at 6 degrees and I have no problem with batten stagger!
  • 07 Dec 2012 14:15
    Quote
    Reply # 1154434 on 1154148
    Anonymous member (Administrator)
    Graham Cox wrote:

    .....................

    However, my cambered sail duly arrived and I bent it on.  It was a very different beast and initially I both hated and feared it.  It had severe negative batten stagger which caused endless grief with tangled sheets for a start and it had none of the docility of the flat sail when hoisting it in a seaway. 

    .........................

                                                                   Stavanger, Friday

    Graham, I bet that some of the negative-stagger problems you got when changing to cambered panels stems from the forward-raking mast. With the mast raking forward, the mast top, where the halyard goes, will be well forward of the base. Ergo increased negative batten stagger when reefing. Conversely, with an aft-raking mast any tendency to negative batten stagger will be more or less reduced.

    Both Johanna and Malena have/had vertical or a tiny bit aft-raking masts. There is still some tendency to negative batten stagger in their rigs, but only moderate, so semi-short batten parrels will handle it without friction problems. On the dinghy Broremann the mast rakes quite a bit aft and batten stagger is no problem. I also noticed on Broremann that there was next to no load on the tack parrel.

    One could argue that a sail rigged this way would be reluctant to swing out in light winds, but I never experienced that as a problem in Broremann. As long as one doesn’t use heavy solid wooden battens, that should not be a big problem. Broremann’s sail was by far the best-behaved junksail I have owned.

    When watching photos of Chinese junks, I never find main or mizzen masts with forward rake, only on some (not all) fore masts. Quite the contrary; several main and mizzen masts can be seen with a slight aft rake.

    My advice is therefore to go for vertical masts, or with a bit aft rake if the boat’s deck layout and interior permit. The added bonus with a bit aft rake is added clearances between the clew and the sea when squaring out the sail.

    Cheers, Arne

    Last modified: 07 Dec 2012 14:16 | Anonymous member (Administrator)
  • 07 Dec 2012 13:51
    Quote
    Reply # 1154427 on 746824
    Deleted user
    Wow, great looking rig. Radical camber on that, I notice the lazy jacks dig into them. I'd want them to be running lines so they can be loosened.
  • 07 Dec 2012 12:44
    Quote
    Reply # 1154393 on 1154374
    Anonymous member (Administrator)
    Graham Cox wrote:I have uploaded a photo of Zebedee's new cambered sails to the public photogallery.  I thought Gary King in particular might like to look at them.  I like the colour! (A little biased perhaps.)  I am not sure how much camber he has but it looks similar to mine (which was supposed to be 4% but is more like 6 - 8% in the lower 4 panels and flatish, with a bit of round, in the top three).  I have asked Alan to send me a report of how the sail handles and will pass anything on that I receive.


    Alan tells to the Yahoo JR forum that the camber in the lower panels is 10%

    Arne
  • 07 Dec 2012 12:09
    Quote
    Reply # 1154374 on 746824
    Anonymous member
    I have uploaded a photo of Zebedee's new cambered sails to the public photogallery.  I thought Gary King in particular might like to look at them.  I like the colour! (A little biased perhaps.)  I am not sure how much camber he has but it looks similar to mine (which was supposed to be 4% but is more like 6 - 8% in the lower 4 panels and flatish, with a bit of round, in the top three).  I have asked Alan to send me a report of how the sail handles and will pass anything on that I receive.
  • 07 Dec 2012 07:54
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    Reply # 1154289 on 746824
    Anonymous member
    Alan has sent me tons of stuff about his new sails, but I have been working flat out on Fantail and not had time to collate it.  Will try to forward it to David asap.  In summary, thus far, he is delighted with the sails, having experienced winds between calm and F5, but nothing constant.  The sails look terrific!  It's 2100 and I haven't even eaten yet, but I will sort out Alan's stuff if I can tonight (or early tomorrow) because suddenly it is so apposite.
    Last modified: 07 Dec 2012 07:55 | Anonymous member
  • 07 Dec 2012 07:08
    Quote
    Reply # 1154261 on 746824
    Deleted user
    Thanks for all this. Having cut all 7 panels for our main, it's not too late to draw in a thinner rounding as they arent sewn together yet. You've all convinced me 8.5% camber might be too much for our ocean crossing to Indo. Think I'll chop it down to 4 or 5%.

    As for Zebedee (great articles btw Alan, if you're lurking:)), I reckon he may have complaints if he is keeping the same battens & yards. But may have helped those times battling adverse winds and currents.
    Last modified: 07 Dec 2012 13:56 | Deleted user
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