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An alternative method of creating a cambered junk rig

  • 21 Mar 2014 21:33
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    Reply # 1522527 on 1516695
    Anonymous member
    Well David,

    Here's my guess:

    With a modest amount of camber, it'll work without complication.
    Well, chafe, but it's everywhere a challenge.

    Much camber, and you'll have additional problems to solve, which is what inventors are after.

    Best of luck,
    Kurt

  • 17 Mar 2014 23:20
    Quote
    Reply # 1519620 on 1518942
    Deleted user
    David Webb wrote:Yes the idea is similar to the flipping batten scheme but the battens do not flip, this function is taken over by the elliptical panels of sailcloth which control the shape of the sail on the starboard tack, the battens control the shape on the port tack. 
        I could use wishbone battens but then the sail is only attached at the luff and leach and has no support through the body of the sail.
        I will probably try an experimental sail on the new boat I have just acquired and let you know how it works, probably sometime next New Zealand summer, as we spend our winters in Queensland for the warmer weather.
    With a full-length wishbone batten you could have an elliptical panel on each side of the sail, which would control the shape on both the starboard and port tack. However, I'm wondering if the panels won't fill up with water when it rains? Perhaps you could put gaps in the panels every so often. Gaps would probably needed anyway for cross-braces between the two sides of the wishbone.
  • 17 Mar 2014 14:19
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    Reply # 1519149 on 1516695
    Anonymous member
    OK, now I get it. the problem I see is that the lowest working batten, when reefed and on port tack, will be unstable and will try to flip over. The battens within the body of the sail will probably be restrained from flipping by the tension in the luff.
  • 17 Mar 2014 04:23
    Quote
    Reply # 1518942 on 1516695
    Anonymous member
    Yes the idea is similar to the flipping batten scheme but the battens do not flip, this function is taken over by the elliptical panels of sailcloth which control the shape of the sail on the starboard tack, the battens control the shape on the port tack. 
        I could use wishbone battens but then the sail is only attached at the luff and leach and has no support through the body of the sail.
        I will probably try an experimental sail on the new boat I have just acquired and let you know how it works, probably sometime next New Zealand summer, as we spend our winters in Queensland for the warmer weather.
  • 14 Mar 2014 15:22
    Quote
    Reply # 1517702 on 1516695
    Anonymous member
    Not sure that I understand, either, but the scheme sounds a bit like Nils Mycklebust's "flipping battens" that he's used on his boats for a number of years, and has written about in NL 42 and earlier issues.
  • 14 Mar 2014 02:21
    Quote
    Reply # 1517412 on 1516695
    Deleted user
    Not that I quite understand your plan, but sounds like work cutting & sewing those elliptical portions plus a flat sail. Right there that's more work than a barrel cambered sail, even before getting to the curved battens.
    Another method is adding hinged battens to a flat sail, seems simple enough (but making hinges takes time too).
  • 14 Mar 2014 00:23
    Quote
    Reply # 1517344 on 1516695
    Anonymous member
    It would be simpler to fit your flat sail inside pairs of wishbone battens. See my articles from 1988, Newsletters 17 and 18 I think. Paul McKay
  • 13 Mar 2014 09:16
    Quote
    Message # 1516695
    Anonymous member
    I have an idea for a cambered sail which I have not seen on any of the fora so thought I would describe and see if anyone has tried it or has  any comments on the idea.
        The suggestion is to build curved battens to the desired camber, these would then be attached by a batten pocket to an elliptical sailcloth panel of the same camber on each side, and this would then be attached to the main body of the sail. Only the rectangular lower panels would be cambered, the boom and upper of the parallel battens would be straight with a barrel cambered foot and top to the rectangular section of the sail. A slit or hole would be needed in the elliptical panels to allow the sail to sit against the battens on port tack. The cambered battens would need a supporting tie to hold them in the correct orientation.
        As I see it the advantages would be that a vertical seamed sail could be used that was basically flat except for the curved head and foot thereby preventing a full length horizontal split in any panel. The sail would be easier to make than a barrel cambered sail as the sail is flat and the camber is controlled by the elliptical panels or the battens.
        Possible disadvantage is that the sail may not set properly when reefed.
        Any thoughts, comments or suggestions?  
       " ...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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