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Flat Sails are Still Okay

  • 26 Feb 2012 20:10
    Quote
    Reply # 836233 on 594527
    Anonymous member
    Unfortunately, the only way we are likely to see a new edition of PJR is if someone bought the publishing rights from Tiller.  Jay Benford is unlikely to invest in the project.

    As well as jokes, a few cartoons would not come amiss.don't you think?  And certainly separate volumes, with, perhaps, the section on handling the rig printed on waterproof paper in large print for older eyes.
    Last modified: 27 Feb 2012 02:54 | Anonymous member
  • 25 Feb 2012 12:28
    Quote
    Reply # 835452 on 834940
    Deleted user
    David Tyler wrote:
    Robert Groves wrote: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.
    Bob,
    I've been wondering - when you made your new sails, did you get some rounding added to the head of the sail, to allow for the inevitable yard bend? If there's one thing that makes a junk sail unable to stand up to a gale, it's having a straight-cut head, which means that when the yard bends, as it must under heavy loads, the middle of the panel goes taut, and the luff and leech go slack, flutter, flap and self-destruct. It's of no use putting some hollow into the leech, the problem doesn't go away. Also, the seams at the top teo battens should have had an inch or two of rounding, for the same reason. I think I've said it before, but it's worth repeating - to make a junk sail set flat, paradoxically, a little bit of camber has to be added in.
    Firstly, to Jonathan and his very honest and informative assessment of the cambered sail. Very informative write up. Thank you..

    Secondly...David, when we built the new sails we did a couple of innovations that will improve the durability of the sails. Each panel has a very small scallop in the leach and luff of the sail to take up some of the slack. This is common practice in the building of non junk sails as well. More helpful is the addition of leech and luff lines that we tension individually on each panel. Experiments are showing that we can attain a certain amount of camber this way and also control any flutter. The new sails have no flutter even in winds of approximately 40 knots that we sailed into near Guadaloupe to give them a fair evaluation. There is a great acceleration zone at each end of the island! Good for testing sails while still near land. Our yards are straight aluminum tubes and there's no bending there. The battens do bend a bit but, other than giving the sail camber, I can't see anything detrimental to the sails shape.

    The use of 7.5 oz sailcoth is a big improvement as well. We find the sails sit more quietly in the lazy jacks without the flutter the old ones experienced when down. We had more damage on the stored portions of the sails than what was in use in heavy weather. Slieve's recommendations for sail catchers require some more review on my part.

    Our old sails were simply too light with insufficient width of tabling. We got another 3000 miles out of them with no more problems, until we went into Hurricane Sean, with a retrofit of wider tabling. When they failed it was the entire panel just worn out and letting go. The old sails actually bellied out in the centre instead of getting tighter as you have indicated. The use of a running parrel made them set flat. We got over 25,000 miles of often heavy sailing out of the previous suit and I expect we'll get far more out of the new sails.

    My feeling on the flat sails is that they are easy to build and maintain. If camber can be built in with luff and leech line and possibly air filled battens then the flat sails will still work. as both cambered and flat depending on the situation. It is nice to experiment but as our passages are mostly over 2000 miles I don't want to find my errors halfway there. I'll continue with the conservative approach and over designed and built systems. While we are slow to change, change is happening slowly.


    Last modified: 25 Feb 2012 12:46 | Deleted user
  • 25 Feb 2012 07:31
    Quote
    Reply # 835383 on 594527
    Anonymous member
    Regarding PJR, I bought the 2nd edition thinking it would be more up to date. So I was a little disappointed that the only reference to any other work was a very slim Appendix at the back that didn't even mention Arne's sterling work. The PJR is the Bible as far as I am concerned but it does need to cover the advances  in camber and sail design.
  • 25 Feb 2012 06:21
    Quote
    Reply # 835350 on 594527
    Anonymous member
    Hello Annie,

    Thanks.

    Since it came up:

    The heads of both sails on 'mehitabel' are straight-cut, but the yards are oval and barrel tapered, and there's a small amount of that taper along the bottom edge. I made a guess how much curve would bend out of the yard. Not very much. So far so good.

    I haven't noticed our yards actually bending, nor the top panel getting loose and floggy, in up-to-a-proper-unpleasant-gale conditions. I've been denied anything worse... Aarrr.

    Curving the sail head upwards a little, curving the yard's bottom downwards a little, or making the lacings shorter toward the ends seem to be 3 alternatives for the same effect.
    The last of those could be retro-fit if the problem arose.

    Although I like our own yards and battens exposed, I also like David's elegant yard sleeving idea.

    Another thought, more in the thread:

    'Practical Junk Rig' is close to 25. Maybe it's nearly time for a book which incorporates what has been learned since the 1980s, into the previous many centuries' wisdom. Perhaps there could be specific contributions by those who have added to our knowledge.

    It should aim to be authoritative and as solidly useful as PJR, while inspiring further evolution - goals which Hasler and McLeod balanced quite well - though it might encompass greater variety. 

    It should be about the size of the Oxford English Dictionary, and come in an even number of volumes so as not to cause a list. And it should have jokes. Lots of jokes and a DVD or two.

    Cheers,
    Kurt

  • 24 Feb 2012 23:34
    Quote
    Reply # 835150 on 594527
    Anonymous member
    Just a point, David.  We cut the tops of the Badger's sails flat and had her out in plenty of weather.  I never noticed the yards bending - I'm not saying that they didn't - but we had to sail ourselves out of plenty of unpleasant situations in a lot of wind.  You may recall that when we cruised th Falkland Is, a notoriously windy part of the world, we only had a Seagull outboard, so had to rely on the sails.

    As ever, Kurt, you speak good sense.  I appreciate what might be termed the technical aspects of my new sail, but they would be dismissed immediately if I felt they compromised the offshore, seaworthiness of the boat.  It seems that the efficacy of flat sails varies from boat to boat.  There are now 3, 34 foot Benford dories that have sailed considerable distances as pure sailing boats, or with auxiliary power that can only be used in a calm.  All have had flat sails.  For my own part, I remember finding Badger a huge amount of fun to sail and could park her on a dime, so to speak.  Indeed, it would be fair to say that I've only started to enjoy sailing again since I fitted the JR to Fantail.

    Kurt obviously thoroughly enjoys sailing mebitabel, and as she has electric auxiliary with very limited range, I think it's fair to say that she is very near a pure sailing boat.  With flat sails.

    Put flat sails on a good hull and you can get somewhere.  Put the best designed cambered sail on a bad hull and you will still be tacking backwards and forwards on the same spot.

    I am thrilled to bits with my rig, but in truth am intrigued to know how the boat would perform with a flat sail.  I guess she wouldn't go as well to windward - at the moment I believe she sails at least as well as she did with the old rig - but she would be more than satisfactory on all other points of sailing.  So far I haven't been out in any serious weather, so can't address all Kurt's very cogent points.  But I will say that the sail is fully automatic; the boat heels very little (she is 50% ballast ratio, however!), possibly less than she did before; I would say that looking at the sail, the battens are doing what they do in a flat sail - supporting the canvas throughout their length; the sail was not that difficult to make, but a flat one would have been a lot easier; the sail doesn't flog.  At all; the only reason I lack confidence in the rig is because I made it!

    At the end of the day, the majority of junk-rigged boats that are clocking up the miles still have flat sails. I am dying to hear how Tystie's new sail performs (not that I'm wishing you to experience a typhoon, you understand).  Until there are more baggy sails on the oceans, I would also be sticking with my flat sails if I were pleased with how my boat performs.  If it's obsolete, it works.
  • 24 Feb 2012 20:41
    Quote
    Reply # 835051 on 594527
    Anonymous member
    Hello Folks,

    David - I'm not expert enough on camber or planform to confuse the two. So I haven't mentioned planform. 

    I am speaking up, as you say - a satisfied flat-sail basic junkie - because I think the apparent emphasis on performance and innovation has one unfortunate result - people being inadvertently led away from the list, given again below. 

    Satisfaction is boring to talk about, and will never dominate the forums. But people interested in the rig, or adopting it, should know that it's as possible now as it ever was for Jester, Ron Glas and Badger, Ti Gitu and a herd of Gazelles, to sail safely and easily and as far as they want to go. For little cost, complexity or trouble. Our Annie Hill's enduring, enabling message.

    Jonathan - Thanks! I hope some other sailors with cambered junks will get confidence and wisdom from your experience.

    Robert - It's a fortunate junk rig that's on a boat well-matched to it. Maybe it's our boat I'm so happy with, and any old rig would do. No...

    Slieve - I don't think we disagree so much as differ in our sailing priorities. 

    I used to fly hang gliders. My last glider was pretty much state-of-the-art in performance, and I truly enjoyed that. But if it had been as hard to land as my previous one or worse, I would rather have flown a Volkswagen.

    --------------------
    Just Once More - A Short List of What a Junk Rig Can Be:
    (which isn't perfect or complete, but I can't refine it right now in calm water with little wind.)

    Tough - as in things that don't snap but do something else instead, like stretching or bending or warning you somehow; proven scantlings
    Resistant to failure - as in not tempting things to snap, chafe, bang...; light strains
    Effective as stormsails - the reefed state should be really well sorted
    Readily repaired at sea - access to battens and attachments and such; lashability
    Less heeling to the boat - unless you like heeling
    Self-tending - what Hasler & McLeod called 'automatic' handling
    Less stressing to spars - distributed rather than point loading
    Cheap - over the long term, in time and money, unless you have extra
    Downright easy to make - unless you savour this challenge
    Not ever flogging
    Inspiring of confidence
    Then add:
    Performance - as desired while maintaining the above, especially if you're influential with your ideas or you're designing for others.

    This is written in a friendly spirit, accusing nobody of anything. I'm commenting only on a somewhat sad aspect of this highly creative period in Junk Rig evolution, and how its new ideas are presented. 

    The only strong opinion I have, is that the list is essential.

    Cheers,
    Kurt


  • 24 Feb 2012 18:51
    Quote
    Reply # 834940 on 833886
    Anonymous member
    Robert Groves wrote: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.
    Bob,
    I've been wondering - when you made your new sails, did you get some rounding added to the head of the sail, to allow for the inevitable yard bend? If there's one thing that makes a junk sail unable to stand up to a gale, it's having a straight-cut head, which means that when the yard bends, as it must under heavy loads, the middle of the panel goes taut, and the luff and leech go slack, flutter, flap and self-destruct. It's of no use putting some hollow into the leech, the problem doesn't go away. Also, the seams at the top teo battens should have had an inch or two of rounding, for the same reason. I think I've said it before, but it's worth repeating - to make a junk sail set flat, paradoxically, a little bit of camber has to be added in.
  • 24 Feb 2012 15:25
    Quote
    Reply # 834772 on 594527
    Anonymous member

    Hi Kurt

    I like you strong opinion and I like your spirit, but I can’t agree with you. Let’s say we are on opposite sides of the floor in this debate, but it is a debate which is well worth the effort. We can all learn from it.

     

    Let me tell a little story which is related to the problem.  My life is very busy, and has been for quite some time (years) due mainly to the grandchildren. Recently I built 4 very simple little hand launch gliders for the boys and learned a lot from the exercise. All were the same 30 cm wing span, but the first had a flat wing section and the rest were well cambered for the first 50% chord and then flat. Otherwise they were almost identical.

     

    (Only) One glide with the flat one had a glide angle of about 12°, but that was a lucky one where the speed and angle of launch was exactly right. All other glides, including all launched by the kids, were stally and unstable, and the average angle was about 18°. All the cambered wing ones gave consistent glides, even from variable launches, including by the kids, and averaged about 8° glides, so not only was the angle much better but the tolerance to mishandling was much greater.

     

    To me, that says it all. Poppy is very tolerant to my bad sailing.

     

    Looking at your list of design features in italics, I reckon that I have ackonwledged many of them in the design of the split rig. Toughter, I don’t believe there is much in it. More resistant to failure, I have made alterations to the construction to address this. More effective as storm sails, this was incorproated in the design from the start. More readily repaired at sea, has been addressed by building the sail in 3 sections so some can be taken down for repair and the boat left with a part rig to continue. Less heeling to the boat, that comes with the better lift/ drag ratio. More self-tending, I’m not sure I understand the problem as I don’t tend the rig, but only raise, sheet and lower it. Less stress on the spars, this is a key feature of the low yard angle and high sail balance of the split rig. Cheaper, well it’s no dearer. Downright easier to make, well there you have me but then we have to include the hugh performance advantage on all points of sail. Ask any decerning sailor who has met the split rig on the water on a one to one basis. There is no competition.

     

    The write up on the split rig is crawling along, but I hope to get some sections out very soon, even if far from complete. As I said, life is very busy as there model aeroplanes to build,

     

    Cheers,   Slieve.

     

    Last modified: 24 Feb 2012 15:31 | Anonymous member
  • 24 Feb 2012 12:48
    Quote
    Reply # 834670 on 594527
    Anonymous member

    Robert, You wrote: 

    "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 do not hold a brief for either camp, flat or cambered, but can only report as I have experienced. 
     
    The Azores and Back (AZAB) Race 2011 may not strictly count as "trans ocean" (although it is longer than the Sydney to Hobart and is nearly the length of the OSTAR ie 2,500 cf 3,000 nm.) 
     
    In my article in the last two newsletters I gave the most honest account that I could of how boat, rig, cambered sails and I stood up to the test. 
     
    Over a combinded mileage at sea during 2009, 2010 and 2011 of well over 4,000 I had plenty of wear on running rigging and lashings but the wear on the cambered sails was limited and acceptable, a few small tears and some worn stitching, and was certainly not approaching that which would have affected performance.  That 4,000 miles has indeed included "a gale or two".
     
    Lexia was the smallest and lightest boat in AZAB Class One and I was single handed whereas the majority were double handed.  I struggled to make progess towards the Azores against the prevailing wind and and waves but so did other bigger and stronger boats such as a Nicholson 32 which retired with forestay failure and a Contessa 32 which finally make it to the Azores with the hull in a state of structural collapse requiring a major rebuild!  Also, on the spectrum of performance for boats to windward, a schooner of any sort comes well behind the sloops and cutters.  Also I was grossly overloaded with more than full cruising equipment and a mass of spares and tools and far too much water, dieso and food.  I didn't need to stop at the Azores, indeed it would  have been better not to but it was obligatory.
     
    On the return, largely reaching, I made up to 140 miles per day, whilst doing very little to sail the boat.  I caught up on my sleep. 
     
    Sixteen Class One boats crossed the start line.  For the combined two legs ie the AZAB , only 6 of the 16 finished , ie Lexia and me and five others, and only one of the others was singlehanded. 
     
    I can't make any real comparison with the previous flat sails because I converted to cambered sails shortly after buying the boat.  However, I have no complaints about the sails or performance.
     
    I hope that this may go some way to answer your statement above.  Jonathan
    Last modified: 24 Feb 2012 21:02 | Anonymous member
  • 24 Feb 2012 04:53
    Quote
    Reply # 834024 on 594527
    Anonymous member
    Wonderful to get response!

    The innovations I seem to admire-but-dislike, running through the HiPower, Fenix, Reddish and later approaches including Arne's, David's, Pauls, Slieve's and others, have all had as their main goal, the improvement of windward performance.

    None were announced as attempts to make the rig tougher, more resistant to failure, more effective as stormsails, more readily repaired at sea, less heeling to the boat, more self-tending, less stressing to spars, cheaper, or downright easier to make. Experience is showing where work is needed for each of the more weatherly rigs to survive. I cited Ti Gitu's case... 

    Being a test pilot, isn't what I'm after.

    I acknowledge that a new approach can be well or poorly applied. Arne, in an exemplary way, has gone far to provide the details a person will need, on the ground, with the sewing machine. And he's not alone.

    Hasler & McLeod's innovations and homework were intended to do those things on my list, as their main goal. My own small refinements, I'll call them, have been in a similar direction. 'It seems to make sense,' guides me.

    Yet I can sail mehitabel back and forth and get into the wind. Responsive, lively - check, check. Glad heart - check. (Somehow, my daughter can do it better than I can, but never mind.)

    I think flat sails are superior to cambered ones. 

    At what? Mainly, the italicised list above, more or less, plus not ever flogging, and ensuring confidence. Various people who are now ready or nearly ready to try their beautiful curvy sails out in their chosen sea, and some who have done, are expressing less than solid faith. To my mind, that list comes first. 

    Since I've already quoted our friend Annie once, '... that last 5% of efficiency comes very expensive.' To that I'd add, it can indeed compromise the very advantages of the basic tough-as junk.

    Well, that's the little voice I want to keep alive.

    Cheers,
    Kurt

    Last modified: 24 Feb 2012 04:55 | Anonymous member
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