Cambered sails VS flat/ hinged battens on a Badger.

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  • 11 Oct 2022 12:32
    Reply # 12949941 on 8784076

    I made hinged battens for my Anna Lucja 2, they are 2,7m long and hinges are the outer sleeve kind. After a thousen of miles in stronger than 25kts despite the inner cable, they began to separate and break down where the pipe overlap was only 40mm with the outer diameter of 35mm over inner 25mm pipe. Nothing bad happened in the hinges where the overlap was 90mm.

    Now I need to decide whether make all overlaps 90mm, which result with smaller camber, or redo the sails and sew in shelves.

    I need to consider not only much more work with sewing, but also the fact, that my flat cut sail with hinged battens use to get proper shape in about 4 - 5kts of wind and boat was making 1 - 2 knots up wind,

    while the sails with sewn in camber starts getting the shape in 8 kts (?), as knowledgable man said. 

    At the moment, I am inclined to remake the hinges rather than remodel the sails and sew in shelves. But, of course, I am not certain whether hinges with longer overlap will last several years. 

    2 files
    Last modified: 11 Oct 2022 19:36 | Anonymous member
  • 10 Oct 2022 09:06
    Reply # 12948316 on 8784076

    Hi Carl,

    using any kind of camber in the sails will improve light air performance and performance to windward.

    Personally I think camber produced by sail shape is simpler and more proven than by articulated battens. I have seen and heard of a number of disasters with articulated battens and they are not as sturdy as non articulated battens with a sail that has camber built in to it. Articulated battens can produce a good performing sail and there are many that have been used for extended periods of time with good results, however for a first time cambered sail something like Arnie's barrel cambered sails would be easier and would give a more predictable result. They would also use the existing battens and sheeting systems , so probably less work.

    All the best with the project, David.

  • 09 Oct 2022 09:51
    Reply # 12947502 on 8784076

    Hi everyone

    I have been reading a lot of posts here about aluminium battens with hinges.

    We now have to get new sails after 10 years' of usage in the Marmaris area in Turkey. Our sails are destroyed by the sun beacause we left them year-round on the booms without sail covers. 

    Our boat Nereid is 36 feet with 2 masts (forward mast being shorter) and flat sails with wooden battens.

    She sails well as long as we don't go too much up into the wind, but the speed is below 5 kts if there is not at least 15 kts wind.

    With the wind from behind she can do up to 7 kts with only the main sail.

    In september, when I was in Bozburun bay, I saw a smaller boat with a Junk sail in the bay. A couple of days later I took up the "race" but I could not overtake him.

    I later found the owner, an Englisman named Alastair who lives in Bozburun, and he showed me his beautiful boat which is built in Bozburun (Bozburun is a boatbuilder village, well known for building wooden boats).

    He told me he has a 50 sq m sail with hinged aluminium battens, using two hinges on each batten. He got help from a member at JRA with the design of this system.

    The hinges are cylindrical and conical at each end, made from nylon, he told me.

    I found this very interesting and I started thinking about the possibility of introducing the same kind of battens in my new sails.

    My main sail is 37 sq m and the front sail i 23 sq m.


    My question to the forum: Can I expect Nereid to become faster if I use this kind of hinged battens? Will there be an improvement in (close to) upwind performance or performance i low winds etc?


    Thank you

    Carl Hyllander

    in Marmaris at the moment



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  • 03 Mar 2020 22:40
    Reply # 8792534 on 8784076

    David D, if you used the existing wooden battens you could easily add hinges by using an aluminium sleeve and tapering the ends of the wooden battens, as David Tyler has indicated. One thing he did not mention however, is that you can make the equivalent of two hinges by using a longer aluminium sleeve so that the articulated ends are separated by as much as you want to provide the camber you need. The wood part of the batten is shortened as necessary to get the overall length correct.

    Also you could do just one batten first (probably the bottom one, so that you can see better what is going on)  and see how it turns out, then adjust as necessary before changing the rest of the battens.

    All the best with the new boat, David.

  • 03 Mar 2020 20:54
    Reply # 8792396 on 8784076

    Arne wrote: PS: Notice that camber is not useful only when fully close-hauled. It produces a lot more drive between a close reach and a broad reach as well. This fact is often being overlooked.

    This is undoubtedly true, but my experience with Arion's flat sail was that once the wind freed to a close reach and beyond, the boat had all the power it needed.  On a broad reach to a run, I often astonished people with larger, sleeker bermudian boats with my ability to hang onto their coat tails, and occasionally get ahead if they had to do foredeck work.

    My new sail is once again cambered, since Blue Moon is a boat with windward potential and I am mostly going to be sailing inshore in lighter winds, but I was happy enough with the flat sail for cruising in open waters.

  • 03 Mar 2020 20:15
    Reply # 8792256 on 8784076

    This is where the website comes into its own.  We are having a "real time" conversation between members in USA, Norway, UK and NZ.  Amazing!

    Re wooden battens: we reckoned to break one about every 10,000 miles on Badger.  We only ever made two brand new ones, from some fantastic, wonderfully close-grained, clear douglas fir, we found from one of the wrecks on a beach in the Falkland Is.


  • 03 Mar 2020 20:07
    Reply # 8792219 on 8787933
    Deleted user
    Anonymous wrote:

    David Da.
    if you look up JRA-newsletter #24, you can see how I added camber in Malena’s flat sail by making hinges in the horizontal battens (1991). I left the top panels flat, but due to the hinges in batten 2 (from top) there actually was some camber in panel 2, as well.

    Later (see NL #26), I had my first tests by adding some bagginess in each panel of that same sail, now with straight battens.

    I notice from your photos that the sails are set with some balance. If hinges are to be tried, you may (or may not) find that the sail should be set with a bit reduced balance to ensure the hinges flip the right way.

    But again, I encourage you to try the rig as it is first, so you get some sort of performance reference.
    Good luck!

    Arne

    PS: Notice that camber is not useful only when fully close-hauled. It produces a lot more drive between a close reach and a broad reach as well. This fact is often being overlooked.

     

    Arne I finally got access to NL#24 and see what you did.  I did not realize you were using up to 3 hinges!  Hence the superior sail shape you could achieve.  The Freedom I sailed had one hinge and that was what I assume others did.

    I wonder about durability of hinges offshore but then it's easy to carry extra tube and pieces.

    Very clever and food for thought.

    David D.

  • 02 Mar 2020 19:44
    Reply # 8788120 on 8784456
    Deleted user
    Anonymous wrote:

    David, dories are tender.  The extra weight in the wooden battens wouldn't make a noticeable difference.  Honestly. And, arguably, a baggy sail might increase the tendency.

    I'm not entirely convinced about baggy sails for long distances.  Alan (Zebedee) is and will be putting new sails to the test when he leaves here, in a year or so. for another circumnavigation.  Designer David and I both agreed to try a small amount of camber plus hinged battens on Fanshi.  He made these (battens) for me and they are presently languishing in Auckland while DHL and Customs agree on what ransom I will be charged to release them.

    Shirley and I have been talking about camber.  She didn't like her baggy sails and found that they were much more stressed than the flat ones.  She changed back after too many breakages, but said that she can't help noticing how well the junks with baggy sails did at our Tall Ships regatta.  For coastal sailing I think they are probably preferable.  Would I want them if heading down for long periods in the S Ocean?  Probably not.  For a simple Trade Wind passage or circumnavigation?  Possibly not, unless I intended to do a lot of exploring along the way.  But of course, the Trade Winds don't always read the books, as most long-distance sailors have experienced!

    As ever, you pays your money and you makes your choice.  As you say, you may as well get to know the boat with the sails that she comes with, first, and you may find that, like most people, when the destination is dead upwind, you use that very expensive iron topsail, which takes up so much room in your boat and get your money's worth from it!  then you can happily keep your flat sails!

    Darn it Annie will I need 2 sets of sails then?  One for Ocean cruising and one for when I sail with the "Squadron"?  LOL.

    At least my engine is new and shiny!




  • 02 Mar 2020 19:02
    Reply # 8788030 on 8787933
    Arne wrote:

    I notice from your photos that the sails are set with some balance. If hinges are to be tried, you may (or may not) find that the sail should be set with a bit reduced balance to ensure the hinges flip the right way.

    To put some numbers on that:

    I find that if the hinge is twice as far behind the mast as the luff is in front of it, then articulation is reliable. 12% balance, with the hinge at 36% of chord is a good ratio to aim for. This assumes a flat sail. Actually, my preference these days is for a sail that is flat aft of the hinge with a little barrel-cut camber forward of the hinge. Then the hinge can be further aft.

  • 02 Mar 2020 18:22
    Reply # 8787933 on 8784076
    Anonymous member (Administrator)

    David Da.
    if you look up JRA-newsletter #24, you can see how I added camber in Malena’s flat sail by making hinges in the horizontal battens (1991). I left the top panels flat, but due to the hinges in batten 2 (from top) there actually was some camber in panel 2, as well.

    Later (see NL #26), I had my first tests by adding some bagginess in each panel of that same sail, now with straight battens.

    I notice from your photos that the sails are set with some balance. If hinges are to be tried, you may (or may not) find that the sail should be set with a bit reduced balance to ensure the hinges flip the right way.

    But again, I encourage you to try the rig as it is first, so you get some sort of performance reference.
    Good luck!

    Arne

    PS: Notice that camber is not useful only when fully close-hauled. It produces a lot more drive between a close reach and a broad reach as well. This fact is often being overlooked.

     

    Last modified: 02 Mar 2020 18:49 | Anonymous member (Administrator)
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