Soft Wing Sail

[Therapy]

Originally Posted by Pericles

SeeYa,


Ilan's sail does work very well and I would choose it for a Gunboat 62, if I had the money for the vessel.

Pericles

I built a model of a cat in 1982 (crude I assure you) that had one unstayed mast in each hull and stiff "sails".

It had no controls and was set free. Course was determined by bending the "rudders". Truly primitive, but very fast.

I would think the Gunboats are expensive enough that they should make one like my model and try it out.

I imagine it would simply HAUL ASS!!

See if you can get them to make me one to prove I am right please.

[Pericles]

Gunboats are semi custom, so if I were rich enough to buy one, I would work with both the boat builder and Ilan to plan the installation. It's a step by step approach.

As for cost, one Soft Wing Sail and one KiteShip - Innovation in Tethered Flight compare very favourably with a full suite of North sails and rigging etc. Contact Ilan for prices.

Pericles

[Lancerbye]

That looks really interesting. The only thing I have a problem with is the very tall free standing rig. That mast will have to be a serious piece of engineering. I like the concept however. How much?

[Pericles]

Lancerbye,

You are asking about the cost of a piece of string, to which the reply is "How long?". Speak to the man. Give him your boat details, go for a demonstration sail and then do your sums. Read below. BTW, the boat is in Turkish waters

SeeYa,

Most things evolve. Where would we be if Leonardo da Vinci had access to modern materials, as you suggested. Ilan's sail does work very well and I would choose it for a Gunboat 62, if I had the money for the vessel.

Delta Yachts - Gunboat catamaran

For downwind work I would prefer a traction kite, as favoured by a number of motor yacht delivery crews. KiteShip - Innovation in Tethered Flight

Certainly contact Ilan with any questions you may have about the wingsail, he will welcome your enquiries and he will explain how his system differs from those you have mentioned.

OMER wing sail Ltd
23 Hohit St. Ramat hasharon
ISRAEL 47226

Email: ilan@omerwingsail.com
Web site: www.omerwingsail.com

[SeeYa]

If anyone's nterested in a quick and pretty convincing overview of the value of frestanding rigs, I guess that you could do a lot worse than talk to Eric Sponberg who's not only enthusiastic and clearly knowledgeable but also has a pretty straightfoward writing style - I understood nearly every word first time round so ...

His site is Sponberg Yacht Design Inc..

He also seems pretty approachable responding personally and immediately to my own recent interest and suggesting that I help by spreading the word so ......

....hope it's of interest; see ya!

[Pericles]

SeeYa,

Many members of this and other marine forums know of and have corresponded with Eric and he is a true gentleman. The free standing mast was not the reason for me starting the thread, it was the Soft Wing Sail, that the mast supports, which I believed would be of interest here.

Knowing now that you have contacted Eric, I am interested to know whether you contacted Ilan about his system, because, if knowledge of new sailing developments is what you seek and specifically, information about the subject of this thread, then Ilan will help you best. For masts, contact: Seldén Mast AB

Good luck,

Pericles

[SeeYa]

I posted here originally because Ilan' sapproach looked very much like the Gallant rig on SV Aphrodite. If my last post was misplaced, so be it but, for me, there was and remains a strong relevance; unless, of course, you keep the threads very narrow in which case it should have been called Ilan's thread.

I also hadn't realised that Sponberg was so well known to you all but I guess that duplication and repetition is something that you have to accept if you're attracting new participants; forgive my enthusiasm - it's normally contagious!

I haven't contacted Ilan because, albeit based on a lack of any real expertise, I felt that he had produced a fairly odd looking solution with too much material/gear aloft for my taste. Sponberg's approach requires a far less complex sail with a more complex mast to produce a much cleaner, more elegant line and I posted details here because, for me, his implementation was more attractive and his rationale more compelling than Ilan's.

See ya!

[jscott]

How do you heave to.

[Pericles]

Head up and sheet out.

Pericles

[BigCat]

I have been working on a similar idea, only I am modifying a junk rig (which I like, and am very experienced with,) to come up with a wing sail, whereas the Omer is a modified marconi rig. My version is lower (AR of about 2) and has sheetlets (sheet parts attached to the leach,) taking some bending loads to the deck. The sheetlets on my version also control the direction of the camber, switching it for port and starboard tacks.

I have drawings on my website of my version, and links to other wingsail efforts to be found on the web, including the Omer. Many people have tried to make money with wingsail designs, and it is rather sad to watch them disappear, one by one, through the years. My interest is primarily for my own use, with any sales of plans being a minor consideration.

[Robertcateran]

Originally Posted by Lancerbye

That looks really interesting. The only thing I have a problem with is the very tall free standing rig. That mast will have to be a serious piece of engineering. I like the concept however. How much?

There are plenty of frestanding rigs which end up effectively no more than a stayed rig. Kelsall, Schionning and Rob Denny with the Harryproa all have come out in favour of unstayed rigs,
Robert

[BigCat]

Originally Posted by Robertcateran

There are plenty of frestanding rigs which end up effectively no more than a stayed rig. Kelsall, Schionning and Rob Denny with the Harryproa all have come out in favour of unstayed rigs,
Robert

My old boat, the Batwing, is still going strong with its original unstayed masts, after 34 years and perhaps 50,000 NM of use. They are solid grown sticks, and so not suitable for multihull use, but they certainly prove the principal-and it is hardly the first success story for unstayed rigs.

[BigCat]

If you trust stayed rigs more than unstayed, check out this thread-http://www.sailnet.com/forums/gear-maintenance/41129-poll-mast-rig-failure.html

And here is a calculator for scantlings for unstayed masts: Modelling Unstayed Masts: Stress at Partners

I suggest 70,000 psi for calculating carbon fiber, if using Vectorply carbon uni, which costs about $33 per pound for VectorPly uni- you also want a few layers of -45+45 glass for wringing strains, maybe 10-15% of the layup.

The math for unstayed rigs is neither new nor complicated, and the trusty Skene's Elements of Yacht Design which has sat on my bookshelf for over 30 years has a formula for designing one in wood.

A hollow wood mast can be made "birdsmouth" style. There are many links for this technique you can find by googling it.

[GordMay]

Bird's Mouth Spars revisited ~ By Gaétan Jetté
Bird's Mouth Spars revisited

[Ilan gonen]

Hello every body,

Just wanted to inform you that Omer wing sail mark II is out there sailing.
It is a better wing sail than mark 1, in almost every aspect .

The system is completely new although the outer skin looks similar to mark 1, airfoil reduced to 11%, performance slightly better, the wing is much lighter, simpler, easier to handle and to trim the sail cloth (three independent sails).

The tests have not been finished yet however, the results we already have are very good.

You are invited to visit my web site (www.omerwingsail.com) and see the new pictures in the gallery.

Ilan Gonen