Segmented Sail

  • 22 Jun 2013 05:57
    Reply # 1324429 on 1324411
    Jim Calver wrote:
    Paul Thompson wrote:However I would not use the bolt-rope method to attach the panels to the battens again. One because of the extra weight and two because changing panels is a major exercise that requires a minimum of two people and preferably three or four. If I were to do it again given that the idea is to easily replace a panel at sea, I'd only consider laced panels as they are a viable preposition to be able to make a panel change on the water.
    Cool! This is a comment I've been looking for. I was anticipating lacing the individual sail panels to the battens but a few questions;  One, what method of lacing would you use using what material for the rope? I am thinking individual lacings but a continuous run from a single cable might be advisable? Also, should there be standing bolt rope-type lashings from each batten to the upper and lower batten, independent of the actual sail material to keep the panel 'window' shape stable?  Somewhat like a topsail schooner. As to the sail edges, would a bolt-rope in the sail panel be advisable to distribute stresses along the length of the material (or layers of tape) and should ferrules (or grommets) be used for the lashing positions through the sail material?
    Jim, I'd use individual lashings to attach the sail to the battens, then if one fails for any reason, the whole lot does not come down. The loadings on the head and foot lashings are not high and just about any thing will work. I've used standard sailmakers luff tape and just burnt holes (just under the rope) with a soldering iron for the lashings. I spaced the lashings about 200mm apart.

    Where you do need to pay attention is the luff and leach. Here you need to transfer the load from one panel to the next. You could use an independent boltrope but I just put good patches in each corner and made a substantial luff and leach tabbings. I used webbing loops in each corner to attach the panel to the batten and to the panel above and below it. I have found that properly made webbing loops are much more durable than grommets, which always seem to start pulling out after a while.

  • 22 Jun 2013 04:44
    Reply # 1324411 on 975831
    Deleted user
    Paul Thompson wrote:However I would not use the bolt-rope method to attach the panels to the battens again. One because of the extra weight and two because changing panels is a major exercise that requires a minimum of two people and preferably three or four. If I were to do it again given that the idea is to easily replace a panel at sea, I'd only consider laced panels as they are a viable preposition to be able to make a panel change on the water.
    Cool! This is a comment I've been looking for. I was anticipating lacing the individual sail panels to the battens but a few questions;  One, what method of lacing would you use using what material for the rope? I am thinking individual lacings but a continuous run from a single cable might be advisable? Also, should there be standing bolt rope-type lashings from each batten to the upper and lower batten, independent of the actual sail material to keep the panel 'window' shape stable?  Somewhat like a topsail schooner. As to the sail edges, would a bolt-rope in the sail panel be advisable to distribute stresses along the length of the material (or layers of tape) and should ferrules (or grommets) be used for the lashing positions through the sail material?
  • 18 Jun 2012 20:43
    Reply # 975831 on 973270
    I designed and built the sails for Carl Bostek's Aphrodite. Both sails are made up from individual panels. They have a bolt-rope on the head and on the foot, the battens have track riveted to them. The track provides considerable rigidity but they also add weight. In this case the bare batten is 8kg (this is a big boat) and the track adds 4kg.

    The rig is a success in that it works as a cambered junk should. Carl is happy and Aphrodite is notably faster than she was under her former Galant rig. She is also well balanced.

    However I would not use the bolt-rope method to attach the panels to the battens again. One because of the extra weight and two because changing panels is a major exercise that requires a minimum of two people and preferably three or four. If I were to do it again given that the idea is to easily replace a panel at sea, I'd only consider laced panels as they are a viable preposition to be able to make a panel change on the water.

    However, I think the whole separate panel idea is irrelevant for us. The Vietnamese were dealing with poor quality materials that were weak and did not last long. In Aphrodite's case, the sails are made from Top Gun a seriously tough and strong cloth with a life expectancy of  10 years or more. The extra weight and complexity in my opinion is not justifiable.
  • 18 Jun 2012 03:53
    Reply # 975126 on 973270
    I know that a lot of people prefer pockets over lashing battens to the sail. I prefer lashings, with the backing batten against the mast.

    Sail-track and batten pockets have in common the basic (but alterable) need for fore-or-aft movement of a batten to remove & replace it.

    Separate sail panels, or sections as Arne described above, may have merit for someone's new sails. Or our next ones if we should outlast them.

    Glad the idea got out.

    Cheers,
    Kurt
  • 17 Jun 2012 19:39
    Reply # 974875 on 973270
    Anonymous member (Administrator)

                                                                           Stavanger, Sunday

       Using splints and wire to repair a batten inside the pocket

    When using my Amateur Method B for joining panels and fitting b. pockets, the batten pockets end up sitting a bit on the "outside" of the sail. Because of that it would be possible to do a repair job to a broken batten inside the pocket just by poking a thin steel wire through the pocket but without poking through the sail itself or touching the critical panel joining seam. The Odyssey III material that I recently used certainly is tough, and the thick PVC at the mast batten pocket is even tougher, but an awl would help to get the wire through. For a long distance journey, bringin material for splints plus some thin fence wire and an awl would  be mandatory.

    Arne

    Last modified: 17 Jun 2012 19:44 | Anonymous member (Administrator)
  • 17 Jun 2012 13:46
    Reply # 974789 on 973270
    Thanks for the feedback.
    Two interesting points; for the blue water sailor,
    • it would be easy to replace blown-out top panels.
    • it would be easier to repair a broken batten with splints than to remove the batten completely and replace.
  • 16 Jun 2012 09:56
    Reply # 974084 on 973270
    Anonymous member (Administrator)

                                                                        Stavanger, Saturday

    Jim and Brian

    I have no doubt that the use of separate batten panels will work just as well as a one-piece sail when all the bits have been produced and assembled, but I bet the separate panels take just as much time to produce as my cambered one-piece sail, assembled with Amateur method B. The rigging of the separate-panel sails will take more time and the battens will take more time to produce as well.

    As for need for floor space; I have just finished a 48sqm cambered panel (barrel-cut) sail. The floor space was only just sufficient for lofting each batten panel - the sewing machine table (on wheels) sometimes had to be rolled aside to allow for lofting. We (2 guys) still finished the sail in 5 ½ day. Rigging such a sail (with batten pockets) takes about 2-3 hours first time.
    (PS 10.4.2022: No it takes a good deal more time. Mating the sail with the battens may take 2-3 hours, but time for adding all the extras must be added, and it depends on calm weather. The worst time thief is that of getting the sheetlets right...)

    For general use I would therefore rather recommend the one-piece sail. Just look at the junk-rigged boats of today. Their (mostly flat) sails have lasted for 20+ years. As far as I know, Ron Glas still has the sails she had when I spotted her in 1989. For deep sea travellers it may make sense to have separate panels - or at least have the sail in two separate sections, laced together at batten 3. Then, carrying a spare top section on board would be useful. For the rest of us I think there is no need for separate panels, in particular today when the sail material is so tough. The (Thai?) makers of the original separate-panel sails had to do with much simpler "canvas" with a much shorter expected life.

    Cheers, Arne

    PS: The replacement at sea of a bent or broken batten with tracks would be (even) trickier than pulling out and reinstalling a new batten in a sail with pockets. For deep sea work I think it is better to use lacing if separate panels are being used. A broken batten can then easily be given first-aid with laced-on splints.

    Last modified: 10 Apr 2022 17:19 | Anonymous member (Administrator)
  • 16 Jun 2012 09:03
    Reply # 974064 on 973270
    'Aphrodite' has separate panels in tracks. She's owned by Carl Bostek. Paul Thompson designed the rig. Annie Hill gave Paul major help setting up the rig, while I gave minor help and got to enjoy sea trials.

    - One awkwardness is that removing a batten involves sliding it all the way forward (or aft) past the luff (or leech.) (This could be designed away...)
    - Durability and fit of the 'luff-rope' that slides into the track are important. 
    - A bent or broken batten means a bent or broken track, complicating repair. 
    - The track is part of the batten, so if the batten itself is of sufficient scantlings, the track makes it heavier.

    Sail track is only one way to attach to the battens. There may be cunningly better ways. I'm thinking that all in all, individual sail panels could be a very good idea...

    Shears,
    Kurt
  • 16 Jun 2012 00:55
    Reply # 973730 on 973270
    Hi Jim

    Chris Scanes (Sails and Canvas) and Robin Blain (Sunbirds) built the cambered sails for Paradox last year. We used separate panels which slot into tracks riveted on the top and bottom of each alloy batten, and also on the yard and boom, where lashings act as 'failsafes'. We haven't used them enough to say how effective the system is - it certainly makes constructing the sails in situ pretty easy, and the camber (shelf-foot) is excellent. The sails felt very powerful in the limited sailing that we managed last season. I'll write in more detail when we've used them for a while. 
    Last modified: 16 Jun 2012 00:56 | Anonymous member
  • 15 Jun 2012 13:53
    Message # 973270
    I visited the junk schooner (lorcha) LARINDA in Bridgewater, Nova Scotia, yesterday, at the owners request.  He is finishing her restoration and wanted an opinion on her junk rig. Her story is an epic one which can wait till later. Her owner says he plans to join the JRA.
    See: http://www.larindaslanding.com/pages/larinda.html
    She has segmented sails. That is, each panel is made separately and lashed to the adjacent batten. I have often wondered about this option and assumed it was problematic for reasons I can imagine but I would like our gurus' opinion on this. They would be easier to make than a whole sail and adding camber would be easy.
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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