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. 

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

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.

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.

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.