Sail Balance - Position Relative to Mast

  • 06 Sep 2017 14:56
    Reply # 5065720 on 4793670

    IMHO, sails with a lot of balance area are very good for going downwind, but not much use for anything else (I exclude split junk sails from this sweeping statement, as they are playing by a different set of rules). When the mast is to leeward, we need to get it into the separation bubble which lies quite close to the luff. When the mast is to windward that doesn't apply, though. My feeling, without much evidence to back it up, is that you probably have a similar situation to that of Jilly, the Vertue that wouldn't tack and sailed very poorly, until Gp Capt Smith replaced the HM sail with one of his Fenix-style sails: high AR, not much balance area. He got some camber from the fanned shape, but that didn't make it a  very good cruising sail, as the batten stagger when deeply reefed was extreme, so I wouldn't go this route.

    The Hasler planform puts the area of the upper panels further aft than sails with a lower angle of yard, and this will contribute to weather helm; getting worse the more you reef. This, along with the longer luff, is a major part of my thinking in Weaverbird's sail. 

    I wouldn't make another flat sail, and I wouldn't add more area, making for a lower AR. Putting in some camber adds only a little extra time and  skill to the process. Also, camber that is well forward in the sail tends to bring the drive further forward, reducing weather helm. The very worst kind of sail has its draft well aft, which both drags the boat backwards and increases weather helm. If your battens are at all flexible in their after part, this too may be contributing to the weather helm.

    All in all, I get the feeling that you might be better off with the short, lower angled yard of Weaverbird's sail, and with plenty of camber, well forward, as in Weaverbird's sail. I set the tack as far aft as I can, but lower angled yard means that there is more balance area towards the head of the sail.

    When I'm back home, you'll be welcome to come up and see the sail for yourself, before I take it off for the winter. You might also contact David Hall, for whom I made a sail to this pattern last winter. It's on the Westerly Nimrod 18ft Quetzal, and the balance has turned out to be just about right.

  • 01 Sep 2017 12:07
    Reply # 5059155 on 4793670

    I wonder if I might steer the conversation away from the split junk rig for a bit to ask about balancing non-split rigs.

    My Coromandel suffers from excessive weather helm, and I've not really been able to correct it by adjusting the position of the original flat 1983 Hasler-McLeod sail.  That's a sail I'm reluctant to modify, so I'm considering building a new sail. I've discussed this in the thread "New sails for Tammy Norie".

    Let's suppose for the moment that I simply build a bigger flat HM sail with a lower aspect ratio and more area in front of the mast.  What can I expect?  Less weather helm?  Trouble tacking?  Bad performance on the "bad" port tack? (At the moment, Tammy sails better on the port tack.)

    And if I further add camber to the panels?

    What are people's specific experiences with large lead on non-split sails? Tell me stories please!

    I'm asking not because I've decided what to do, but because I have not and I think this is the right thread to record experiences.

    Last modified: 01 Sep 2017 12:10 | Anonymous member
  • 31 Aug 2017 14:27
    Reply # 5057687 on 4793670

    Thank you very much for writing this up Chris — exactly what I was going to ask you to do rather than re-interpret your experiences myself.

    I'm impressed by what the split junk rig does in the conditions I've seen. As someone for whom the fun starts at F6, I'm looking forward to hearing how you get along in a blow!

    Also, if anyone wants to study pictures of the rigs mentioned (or just see nice pictures of boats) I've put an album up at https://www.flickr.com/photos/rptb1/albums/72157685700394110

    I'd just like to clarify that when I said "control issues" I meant that Chris related to me that he'd had an issue with control on entry to Portsmouth Harbour, and that I'd ask him to explain it later himself. It's not that I had concluded anything about the rig.  "Minor control issue under tricky circumstances at 4am which might be unrelated to the rig" would've been a better choice of words.  I apologise to anyone I've annoyed with my vague statement.

    Last modified: 31 Aug 2017 15:38 | Anonymous member
  • 31 Aug 2017 13:08
    Reply # 5057575 on 4793670

    This response to the previous post is from Chris, on Emmelène.  Context: I’m relatively new to junk rig and have retro-fitted a split-junk to my Coromandel.  More details at https://emmelenevoyages.wordpress.com/

    As Richard said, for one week, I tested this rig on the south coast of the UK, in light airs, cruising alongside his Coromandel, Tammy Norie.

    I’m absolutely delighted with the split-junk rig: both its sailing performance and its ability to be easily controlled.  The phrase in the above post, “control issues”, may mislead readers of the forum.  My split-junk rig is extremely simple to control. 

    The main-sheet is under significantly less tension than the original “hi-power” rig.  Indeed, the sheets leading to each batten often hang rather loosely, which initially came as a surprise to me because my main experience has been with dinghies and Bermudan-rigged or gaff-rigged yachts.  Meanwhile, despite this low sheet tension, the rig drives the boat with good power, to windward and on other points of sail.

    Indeed, this lack of sheet tension is one of the many features that I love about the split-junk.  It means that it is extremely low-stress (low anxiety) for me, as I can sheet in or out without necessarily using the cleats on the pushpit.  Just gently tugging on the lines with a hand suffices for subtle, temporary sail adjustments.  Tacking and gybing are quiet, calm manoeuvres.

    That said, even if I don’t adjust the sail much, it drives in all conditions (that we encountered – mainly light airs around force 3 to 4) and many sailing hours went by this week during which I certainly didn’t need to adjust the sheet – or the tiller.  For this is the beauty of the split-junk rig for the Coromandel: no weather helm.  The rig proved balanced to perfection.  My tiller sits centrally whether I lash it or not.  It’s a joy to be able to set the boat on most points of sail, then let go of everything and enjoy a cup of tea as she sails along hands-free on a reach, for example.  The only self-steering I needed on a run downwind was a bungee on the tiller.  The split-junk rig is truly exemplary in terms of balance on the Coromandel.

    To let power out of the sail, it’s true that because the sheet is not pulling hard itself, it requires a bit of help in light airs to pay out the line so that the sail is empty of wind.  This may be partly because my main sheet is running through old pulleys and tackle, and is stiff old rope also.   Using the rudder to point the boat up helped me empty the sail.  I have not tested how to heave-to in heavy weather, but my own limited sailing experience would encourage me to at least lower some panels (and maybe all) if I want to stop the boat in a seaway.  My initial impression is of easy de-powering and good control at all times so far.

    The only time “control issues” – which I maintain is too strong a phrase - occurred was when my own seamanship was justifiably in question in a busy harbour mouth, at night, with confused seas and strong headwinds over tide, whilst the outboard motor was driving the boat, along with the full sail.  I made a mistake, and that is not the rig’s fault, but my own.  It was simply resolved, with no drama from the rig, by lowering the sail. 

    In summary, the split-junk rig has proved excellent in my opinion (especially to windward), on this first cruise aboard my Coromandel, in fairly light airs.  It remains to be tested by me in heavy weather. My split-junk rig is perfectly balanced and easily controlled.  I am definitely a convert!


  • 30 Aug 2017 20:33
    Reply # 5056545 on 4793670

    A simple question to split rig sailors: doors letting go the sheets always depower the rig?

    If not, how does one reliably depower? Drop the sail?

    Are you able to heave to reliably?

    Amiina literally sailed rings around Tammy Norie this weekend, and Chris Boxer aboard Coromandel Emmelène with Amiina's old sail also performed well, but not without some control issues. More on this later.

  • 26 Aug 2017 12:32
    Reply # 5049494 on 4793670

    Hi all,


    I made the jibs of RUNA !completely! new and had some sailing last week on the lake of Constance. Wind was poor all the time, once I had a 2bft sailing for a short time, where she showed a good performance. I was overtaken by a 3 times bigger boat, his skipper was wondering that I went to windward in the same direction like he did. Balance is right now, no leehelm anymore, no backwinding of the main. Jib sheeting angle is 11°. In those low winds (3-4 kts) the sail did not perform like I wished, I was mostly hanging around just like the sailcloth, sometimes awfully hobbyhorsing in those nasty overlaying waves created by ferries and motorboats, whereas the bermudan rigged boats still made some speed, because having in relation much more sailarea than RUNA. I lost about 2 m² by shortening the jibs.

    Some fotos of the sail in the harbour, it is not yet set perfectly, especially the top panel needs to be altered to match asthetically to the other panels. (Look at fotos in my album). Perhaps I should add another panel to gain more sailarea when sailing in this low wind region.


    Much thx to Slieve for his very helpful advices in the month of July by mail. I strictly followed them and can say that the new jibs do their job very well.

    Bert

    Foto: Runa to the right ;-), looking from Dingelsdorf to Überlingen

    Last modified: 26 Aug 2017 13:13 | Anonymous member
  • 08 Jul 2017 15:16
    Reply # 4938454 on 4793670

    Well, the 2017 Round the Island Race has been and gone and little Amiina has successfully made her fourth circumnavigation. The first race was blustery, the second benign, the third had no wind and the fifth (this year) was variable between force 2 and 5. The fourth race was a non starter as winds off the Needles and down the back of the Wight were in excess of 40 knots. This year's result was entirely credible and but for two suspect navigation calls, we did ourselves proud and earned plaudits from others.

    For me, Amiina is an absolute joy to sail. The unique combination of a Van der Stadt hull, with sea keeping characteristics of a much larger yacht and a Slieve designed and made split sail is so alluring. The rig is so simple to raise. lower and handle and quite the most efficient junk rig I've had the opportunity to experience.  

    But most of all, it is the fact that you really can begin to race rather than cruise behind everyone else and even when conditions get a bit hairy, both boat and rig seem to keep performing without concern and respond, dinghy like, to any helm command.  I have to say that I suffered boat rage this year when another competitor cut me up on the finish line, he on starboard and us on port. I tacked away just before we crossed paths and then virtually immediately slung in a tack as he was amidships.  A tad too soon as it happened and collision was imminent, but here is the point - the split rig immediately reacted to my helm movement and stalled, then as I pulled the helm again, the sails instantly filled and we sped off to the line.

    So, I'm no technical expert on boat or sail design, but I do know when something feels right and Amiina with her split rig brings miles of smiles.  Have no doubts, this is a rig to seriously consider.

    Steve Peake


      



  • 25 Jun 2017 20:29
    Reply # 4916985 on 4793670
    Deleted user

    Hi Guys,

    Just to put your minds at rest, I am copying here a quick note re our recent race from Poole to Yarmouth.  Little Amiina with her 'scary' 33% balance did best of all the boats not using Spinnakers.

    They had all the hard work, stress, dangerous lack of control, breakages, broaches etc., and Amiina sailed blissfully through with so little fuss, beautifully balanced, and totally in control.  What is more with a fairer TCF, we would have been first.

    Now for the Round the Island races on 01/07/17.

    Sam Gill Trophy - 20/05/17

    "20 mile race, mostly off the wind from  East Looe Outer buoy (Poole entrance) to Yarmouth Pier via North Channel and Hurst Narrows.

    14 boats took part.  13 BR, of which 4 Van der Stadt Splinters + 1 split-junk Splinter.

    Wind southerly F4 rising to F5.. Elfin and Whisper used their spinnakers all the way. Whisper had a full sized spinnaker and when it worked she did well, but she broached a couple of times and eventually broke it.

    Elfin had a half sized spinnaker and managed it much better, but still it was hard work.

    Amiina sailed very easily, with no effort, and only the lightest touch of weather helm.

    Interestingly for the Round the Island race, the Island Sailing Club has given Elfin a TCF of 0.818, Sparkle 0.821, and Amiina 0.776... With these TFC's in this race, Amiina would have been 1st.

    In this race you can see that Elfin, with the bigger main, and spinnaker had a TCF of 0.744, Whisper 0.752, & Amiina 0.762!!!

    (See photos and Results sheet in my photo album.)"

    Last modified: 25 Jun 2017 20:33 | Deleted user
  • 23 Jun 2017 16:30
    Reply # 4914283 on 4793670

    Sorry for the confusion to which my postings contributed.

    First of all: I'm no native speaker in English, so feathering into the wind means for me the sail shows its luff direct in to the wind. This is done unto a certain amount but not as a windvane does.

    Second: I sewed the sail following the write-ups of Slieve (only the main was developped in a more simple matter). My only mistake was the disbalancing because of an error what balance means.

    Third: As I changed from a flat to a cambered sail I did not take in account that camber produces such another CoE in the sail which led in combination with overbalancing to a severe leehelm.

    Fourth: I did not want to make completely new jiblets without having solved the problem with the leehelm, so they were cut down and a broadseem was put in, to have the right sailshape out of the form. This showed me that due to the smaller jibs CoE and CLR now do work good together. I have carefully read all your comments, I reread the advices of Slieve and compared to my drawings. Everything is ok, but when I drew up the new jibs with their shortened length following the article of Slieve, and layered them over the old (recut) jibs, it can be clearly seen that broadseeming (even done carefully and with the help of a form shaped to the right camber) is absolutely not the solution. Indeed this has the bad consequence that the sheeting angle reduces to something at about 7-6°. I even looked again at the drawings of the main wondering if I had put to much camber in it - but that is looking fine.

    The smaller sheeting angle of the actual existing jibs explains the phenomen of back-winding and the tendency of the sail to develop drive when it should be depowered.

    So the only way to get my sail working right is to cut and sew new jibs. 

    Thx for your very helpful input.

    Bert

    Last modified: 23 Jun 2017 16:35 | Anonymous member
  • 23 Jun 2017 09:29
    Reply # 4913851 on 4793670

    Bert, can you possibly upload some of your working drawings to your album?  I'm sure that whatever your issue is, it will prove to be something quite simple, because Slieve's rigs have proved very satisfactory on other craft.  If other people can look at the profile, your figures and the sail details, I think we should be able to get to the bottom of this, and have you sailing happily before summer is over!

       " ...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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