The Cambered Panel Junk Rig

  • 15 Apr 2011 16:04
    Reply # 571276 on 566428
    Thanks Arne & David. It's a little hard to evaluate GG's rig at the moment, mainly because she's still sitting on my patio. Up until now, I haven't put too much thought into the science of my sail, other than reading PJR and trimming as best I could. It's only since I joined up that I realise there are later developments might give me a worthwhile performance boost.
    My Corribee is pretty easily driven, and most of the time I am impressed with the rig, but it does occasionally lack punch if beating into chop. This season, I will try to get my head around the wealth of knowledge on this site and evaluate my own setup more closely.


  • 15 Apr 2011 00:02
    Reply # 570870 on 566428
    Declan,
    I don't think the question of "more heel or not" can be answered in terms of "hinge versus cambered panels", only in terms of amount of camber and its position. More camber gives more power, which is useful in driving a heavy boat to windward, and may allow you to point higher in a choppy sea, but in any rig, more power always comes at a cost of more drag, which in a sailing boat means more heel.
    With a hinge, it is difficult to get the maximum camber far enough forward, and it is difficult to get enough camber. With well-cambered panels, it can be difficult to get a good "set" to the sail. On "Ivory Gull", I got on well with a single hinge of not very great angle, combined with a cambered panel of not very great depth of camber. Is it possible that you could experiment with adding a little camber to one or two panels of your existing sail, keeping the hinge, to try the effect?
  • 14 Apr 2011 19:58
    Reply # 570722 on 566428
    Anonymous member (Administrator)

    Stavanger, Thuesday

    Declan

                          Hinges versus cambered panels

    My (felt) experience when changing from a sail with hinged (articulating) battens to cambered panel sail (in Malena in 1994) was that the speed to windward was slightly improved and in any case much better than that produced by the first flat sail. The hinged batten sail (see NL24 p.22) had 10% camber and the max camber point was 50% from the luff. The cambered panel sail (see NL 30 p.21) has only 8% camber with max camber 35% from the luff. My gut-feeling is that Malena sailed more upright with the cambered panel sail and I wonder if her improvement in speed to windward mostly was a result of reducing the weather helm due to the forward placement of the max camber point.

    I don’t know how much camber your articulating-battened sail has today. Whether your new cambered panel sail will be better or not will depend on how much camber you go for and also where you put the max camber point.

    Arne

  • 14 Apr 2011 18:46
    Reply # 570670 on 566428
    Thanks for posting that Arne. I have a notion that I may have a crack at a cambered sail in the next year or so, if I can be pretty certain it'll point significantly better than my articulating-battened rig. 
    Naturally, I will have lots of questions when I finally get to turn my attention to such a project. One thing I'm wondering is whether a lot more heel is encountered with the cambered rig. I find my boat is wonderful for bringing out disabled members of my club's Accessible Sailing programme, and for that I really value the lack of heel.
  • 09 Apr 2011 05:16
    Reply # 567139 on 566428
    Congratulations, Arne!
    I've just finished reading through the 4 chapters that you've put onto your page. I have to say that you are creating something of great and lasting value to all those who are coming new to the rig, and who are wondering if they have the skills to start on making a junk rig for themselves. You are showing them how it's done, in a very clear writing style that is easy to follow. Yes, they can do it!

  • 07 Apr 2011 22:58
    Message # 566428
    Anonymous member (Administrator)

    Hi all

    I have just uploaded four chapters of an essay called,

    "The Cambered Panel Junk Rig". It should be available for both members and non-members of the JRA.

    I hope its contents makes some sense to you.

     

    Arne Kverneland, Stavanger

       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

                                                              Site contents © the Junk Rig Association and/or individual authors

Powered by Wild Apricot Membership Software