Subject: Re: [harryproa] Re: SoftWing
From: "Jerry Barth shredderf16@sbcglobal.net [harryproa]" <harryproa@yahoogroups.com.au>
Date: 11/30/2014, 12:34 AM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

 

Mike,
There's another variation that some US guys were developing that looked pretty good also. It had an articulated nose and camber control through lines running to blocks on top of the sail. There was a video but I forgot even the name of the company. Another JRA guy is doing the aero junk. This is kind of an inside out concept where the ribs are on the outside of flat sails, the idea being that the sail will be forced against the inside of the ribs and make the proper camber. That's my most recent favorite. I think at the air speeds we're talking about something like that is very close to the performance of a two sided wing with a lot less weight and expense. The swing wing is cool but for the money there's probably better solutions out there. The last five JRA magazines have had a lot of good articles about this stuff. For example I believe the last one had an article by David Tyler about using carbon sleeve material to build battens and noses for his latest wingsail. There is also a wingsail forum with a lot going on. I too am working on my house. I'm hoping that one day the wife will release me from her remodeling addiction so I can work on my boat.

Jerry Barth

"Mike Crawford mcrawf@nuomo.com [harryproa]" <harryproa@yahoogroups.com.au> wrote:
 

Jerry,

  Thanks for the reminder about the JRA.  I meant to join back in 2011 when David Tyler was discussing the swing wing, but then got sidetracked.  Tried to join ten minutes ago, but the site is down, so I'll have to try tomorrow.

  In the meantime, what do you think about the SoftWing versus the Swing Wing?
 
  I like the three-section frames that produce a nice camber without any folds, and I like that they are smaller, lighter weight, and more numerous than on the junk.  That's the first soft wing sail I've seen that honestly looks like a wing from both sides, while also not needing hydraulics to shape the sail on each tack.

  On the other hand, do more frames with more joints mean more chances for failure?  Or more chances for minor failure, but fewer chances for major failure, given that each frame is less lightly loaded?  Is the smooth wing shape worth the expense of having to get a rotating mast, or at least a rotating boom?  Worth the extra sail stress and the expense of designing for it?

  I was completely sold on the Swing Wing for a while, but now that I've seen the Soft Wing, it's hard to imagine putting the junk rigs I've seen on such a sleek proa.

        - Mike


On Nov 26, 2014, at 4:16 PM, "'Jerry Barth' shredderf16@sbcglobal.net [harryproa]" <harryproa@yahoogroups.com.au> wrote:

 

Mike,

   The Junk rig guys are making some good progress on soft wings.  There are two or three different variants, you can look at them in the members section of the Junk Rig Association.  They’re also using alu light poles for masts.  It’s well worth paying the $15 or so a year to be a member, their magazine is very good as well.

Jerry Barth

 

From: harryproa@yahoogroups.com.au [mailto:harryproa@yahoogroups.com.au]
Sent: Wednesday, November 26, 2014 1:48 PM
To: harryproa@yahoogroups.com.au
Subject: [harryproa] SoftWing

 

 


  More updates on the SoftWing sails:

    http://www.voiles-alternatives.com/viewtopic.php?f=3&t=336
    https://www.facebook.com/media/set/?set=a.284279928416094.1073741829.169341956576559&type=1
    https://www.facebook.com/pages/KISS-Multihull-AB-T29/511834502238630

  They have been testing what they are calling the V14 sail on a T29 trimaran with what appears to be a 12m stayed mast.

  The sail is not yet optimized, particularly for reaching, but they did say they can point ten degrees higher than a Farr 40, while moving faster, tacking through 60-65 degrees. 

  And that's on a 9 meter 1200 kg trimaran with an upwind SA/D of 58, not a 12 meter 700 kg proa with an upwind SA/D of 70 to 90 (depends upon the mast)!

  It's exciting to see the tests with a larger sail.  The T29 might only have a 12 meter mast (estimating from photos), compared to BL's 18+ meters, but that's still a more useful example than the earlier tests with the smaller boat.

  My dream of someone else doing all the hard work of developing a reefable wing sail that lets me use a fixed mast is slowly coming true.

        - Mike

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Posted by: Jerry Barth <shredderf16@sbcglobal.net>
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