Rudolph,

  I had some questions about this rig back in 2008 that no one really addressed, probably because there was a heated discussion on the dynarig at the time.

  But now that we're talking about the swing wing:

  - What costs less? An easyrig with an 800 cm deep wing mast with sail track, a normal mainsail, an easyrig with a wharram soft wing sail, or a boomless swing wing?  The swing wing saves on the cost of the boom, but adds many parts and frames.

  - What's safer to have up as bare poles in a big blow or on a mooring? The wing mast might create noticeably less drag than the round mast of a soft wing or swing wing, if feathered into the wind, but I have heard about boats with bare wing masts starting to sail while moored in crowded harbors.

  - Given the need for several mainsheets for proper sail shape, what's more efficient?  A deep wingmast with a semi-self-regulating rotating easyrig boom, a self-regulating soft wing, or a swing wing?

  - Which would be easier to shunt?  Do you think one could rig up a series of blocks to allow the several mainsheets to feed into one?

  - What's most reliable?  Fewer parts are better, such as with the soft wing, but less drag creates less structural wear-and-tear, such as with the swing wing.


  What do you think? 

  I want the true airfoil of a double-skinned sail, but I'm timid enough to want to see someone else implement it on a proa first. 

---

Other swing-wing links:

     http://www.dunnanddunnrealtors.com/Catamaran.html
     (see top-view drawings 1/4 of the way down the page)

     http://www.woodenboat.com/forum/showthread.php?t=54225
     (see a bottom-view photo 1/3 of the way down the page)
     (posted by Kim in 2005!)

     http://www.themultihull.com/wharram2/jp1.htm
     (see the side-view photo on the far right)


        - Mike


 

 
Rudolf vd Brug wrote:

 

Hi,

 

I have built two easyrigs and I expected the second one to be built at least somewhat faster.

It wasn't. You might conclude the first one was built efficiently then, but to me it means that they take a lot of time to build.

Especially the boom. Also I would like to see a much simpler rig.

A freestanding non rotating mast, as little boom as possible, and a sail configuration that controls it's own shape.

Mike mentioned the junk rig, and it's (lack of) performance. But what about the Swing Wing rig? See http://wharrambuilders.ning.com/profiles/blogs/sailing-with-pha-tiki-30-n119-1

Soft wing sails may be able to give the performance needed for fast boats. They certainly are simple, low stress and cheap.

regards,

Rudolf

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