Flat Sails are Still Okay

  • 24 Feb 2012 01:57
    Reply # 833912 on 594527
    Deleted user
    When I read the travails of Ti Gitu's rig in the newsletter I wondered if those people will introduced themselves to the very article that appears before it. It appears to solve the problem.
    Last modified: 24 Feb 2012 01:57 | Deleted user
  • 24 Feb 2012 00:44
    Reply # 833886 on 594527
    Deleted user
    Easy Go continues to sail well on all points of wind with her flat sails. Having just completed her second set in this fashion then out sailed a cutter rig to windward in 25 knots of wind I think I''l stay with this style. I don't think its all about the sails. Two masts and the dory hull have given Easy Go good sailing.

    I'm waiting to hear the results of a cambered sail in trans ocean racing and how they stand up in a gale or two.

    I'd certainly like to go to wind faster in light airs, but I much prefer to get to the end of an ocean passage.
  • 23 Feb 2012 21:27
    Reply # 833742 on 833693
    Kurt Jon Ulmer wrote:Hello Folks,

    I'm re-opening this discussion after reading the article in JRA#58 on Ti Gitu's experience with cambered panel sails, and before mehitabel and I meet several other junk-rigged boats on New Zealand's east coast, where we will quite likely embarrass ourselves sailing to windward... 

    I want to keep a little voice alive in the JRA, that recognises real merits in the flat sail version of the junk, and which would recommend a flat sail for a new rig, even in this suddenly modern era.

    It's popular in these pages to say that no one way is better than another; they're just different ways. Horses for courses, etc... But I read an obvious bias in the JRA forums, towards new innovations and away from still very recent, but suddenly out-of-fashion innovations...

    Why does the JRA classify the rigorous work of the 1960s as 'the early days' of a millenniums-old process of invention, and as no longer 'in current use?' (he looks up...) The Smart Car and the Hummer, cool as they are, can't obsolete family sedans and pickup trucks in a decade. 

    It isn't only cheapness and simplicity and the joy of not sailing to weather.

    Ti Gitu's experience is relevant, and won't be less so even after Paul and Mo have worked out the wrinkles.

    Cheers,
    Kurt


    Hello Kurt,
    Yes, flat sails are still okay - for some people, some of the time - and by all means keep recommending them to those people.
    But please don't confuse the flat sail/cambered sail issue with the planform on which it is used. On the "early days" page are planforms that nobody should consider nowadays. Jester was Blondie's first attempt, and is a poor rig, taken all round. So is the Newbridge HiPower rig. The Fenix rig is a very poor rig to put on a cruising boat, having taken the fanning principle to extremes. The Hasler McLeod rig appears on both pages, after earlier discussions. It is the only rig that can be said to have been rigorously worked on in the 1960s. The Reddish rig was an attempt to codify genuine Chinese rigs into something we could use, but didn't really succeed, in my view. 
    Arne Kverneland's planform is based on HM, with an improvement in the top sheeted panel shape which is worth adopting. Arne chooses to put in a lot of camber, but his planform can be used, with no camber or less camber than Arne uses, and it would still be the right sail - for someone other than Arne.

    For myself, I have come to the view that there is a real problem in adding camber into high aspect ratio sails with a high-peaked yard, and that two masted rigs present a camber-adding problem that I am unable to solve to my entire satisfaction. With a lower peaked yard, as on Van Loan rigs, the problem is soluble - but I, personally, don't like the look of the solution.

    One masted rigs are different. There, with lower aspect ratio, and a fanned planform that goes back millenia before the HM days in the 1960s, the problems of adding camber to the panels is soluble. Even so, a flat-cut, fanned sail is a better sail than a flat-cut HM sail ( the Chinese knew that, but Blondie didn't fully hoist it in, I don't think), and I would happily recommend anyone who wants to make a simple, one piece sail out of a polytarp to use Fantail's planform. It will camber, when the wind pipes up, if the spars are light enough. Only in light breezes will it hang flat.

    Yes, flat sails are still okay, and please go on being the still small voice that recommends them to people who either don't need or don't want to sail fast to windward (not me - there is much joy to be had in sailing a fast, responsive, lively boat to windward. It gladdens my soul). But let your recommendation include advice on which planforms are to be avoided, having turned out to be not good. 

    Finally, if there is a bias in the JRA fora, it is because the people who are posting are interested in innovations. If people who were more interested in other aspects of junk rig sailing would speak up more, there would be no such bias. Let's hear from those who are entirely happy with their flat sails!
    David.
  • 23 Feb 2012 20:45
    Reply # 833726 on 594527
    Kurt, it has been proven that cambered panels give better performance than flat panels. However if you are quite happy with your flat panel sails then in the long run that is all that matters. If Arne hadn't done the R&D on camber and not published his results then my sail too would be flat.
    However you are about to have the experience of comparing the two and I look forward to your impressions.
  • 23 Feb 2012 20:36
    Reply # 833721 on 603438
    Arne Kverneland wrote:
    Gary Pick wrote:I built my sail Arne style and yeah it's a bit fiddly to sew but I don't think there's that much more work than a flat sail. I live on a coast that is going to guarantee windward sailing at some stage, so If a cambered sail will give me an edge then it's for me.

    Gary,

    could the fiddly part of sewing your sail stem from you assembling the batten panels in a different way than I had described?

    Arne


    Okay a very late reply here. Arne you are probably right. That and the fact that I went with webbing loops instead of pockets for my battens.
  • 23 Feb 2012 19:54
    Reply # 833693 on 594527
    Hello Folks,

    I'm re-opening this discussion after reading the article in JRA#58 on Ti Gitu's experience with cambered panel sails, and before mehitabel and I meet several other junk-rigged boats on New Zealand's east coast, where we will quite likely embarrass ourselves sailing to windward... 

    I want to keep a little voice alive in the JRA, that recognises real merits in the flat sail version of the junk, and which would recommend a flat sail for a new rig, even in this suddenly modern era.

    It's popular in these pages to say that no one way is better than another; they're just different ways. Horses for courses, etc... But I read an obvious bias in the JRA forums, towards new innovations and away from still very recent, but suddenly out-of-fashion innovations...

    Why does the JRA classify the rigorous work of the 1960s as 'the early days' of a millenniums-old process of invention, and as no longer 'in current use?' (he looks up...) The Smart Car and the Hummer, cool as they are, can't obsolete family sedans and pickup trucks in a decade. 

    It isn't only cheapness and simplicity and the joy of not sailing to weather.

    Ti Gitu's experience is relevant, and won't be less so even after Paul and Mo have worked out the wrinkles.

    Cheers,
    Kurt


  • 27 May 2011 23:17
    Reply # 603438 on 603178
    Anonymous member (Administrator)
    Gary Pick wrote:I built my sail Arne style and yeah it's a bit fiddly to sew but I don't think there's that much more work than a flat sail. I live on a coast that is going to guarantee windward sailing at some stage, so If a cambered sail will give me an edge then it's for me.

    Gary,

    could the fiddly part of sewing your sail stem from you assembling the batten panels in a different way than I had described?

    Arne

  • 27 May 2011 14:43
    Reply # 603178 on 594527
    I built my sail Arne style and yeah it's a bit fiddly to sew but I don't think there's that much more work than a flat sail. I live on a coast that is going to guarantee windward sailing at some stage, so If a cambered sail will give me an edge then it's for me.
  • 26 May 2011 13:21
    Reply # 602049 on 598776
    Deleted user
    Paul Thompson wrote: ..
    The extra line that some are making a fuss about is what is called in the west a Hong Kong parrel. Hasler mentions them in PJR (page 47 in the second Ed.) but he did not know what they were for. An understandable mistake since he also thought that junk sails are flat and since he used modern sail cloth which has tremendous diagonal stiffness he would never have see any reason for them.

    Hong Kong parrels are used when the cloth does not have enough diagonal stiffness to keep intact the parallelogram that makes up the shape of each panel. When the cloth lacks diagonal stiffness, you get diagonal creases in each panel that is complaining. The Hong Kong parrel is then rigged diagonally from the top batten to the lower one. The angle should be 45 deg or more, generally the more acute the angle (within reason) the better as less acute angles have more of a tendency to pull the battens together. The parrel is normally rigged in the luff area but I can see no reason why they could not be rigged in the leach area where they would have less effect on the shape of the sail.

    ..

    So lemme get this straight.

    Hong Kong parrels were only used around Hong Kong,  now you've got me diving into my copy of "The Junks and Sampans of the Yangtze". There is no mention of HK parrels there (Hasler notes he didnt see any other reference to them either) Looks like junks everywhere else had quilted sails - that is reels of diagonal lines from yard to boom so they didn't need HK parrels.  

    I have a suspicion Hong Kong junkmen, after observing foreign sailing ships and their ballooning sails, reduced the number of battens, got rid of the quilts and liked the results. They had to invent HK parrels  to fix a problem which popped up when all those diagonal ropes were removed. So maybe ballooning sails, or cambered as we say, was not an accident.

    Last modified: 26 May 2011 17:36 | Deleted user
  • 26 May 2011 02:08
    Reply # 601673 on 594527
    Poor bloke's on his own - who else can he take?
       " ...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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