Rudolph,

  Thanks for the detailed reply.  I was actually in the process of writing an "I posted to soon" post.  When I originally looked at the link you sent, my browser bombed out and didn't load the bottom half of the page.  I wasn't aware of the 2008 and 2009 design upgrades.

  The 2009 wishbones do look much better in terms of the red padding used to keep the wood off the mast.  That might be enough to cut down on clatter and wear if the downhauls are reasonably snug.  I'd definitely want as much padding and as little friction as realistically possible (given weight and materials limitations).

  The shape on the leeward side of the sail with the 2009 double wishbones is beautiful.  I can't think of a nicer shape.  Plus, it will keep that shape without constantly trimming strings and watching telltales.

  As with Gardner, I do worry a bit about the hinge joint if running in a strong breeze. 

  I'd feel better with a magical indestructible composite batten that's light enough to taper into a nice curve on its own, without a hinge, and tough enough to take the bend produced by a serious gust.  That would allow the wishbone fronts to be made from wood while using the benefits of composites for the batten.

  Is this realistic?  I've seen fishing rods that can bend in a 360 degree arc, so my hope is that it would be possible to create such a batten.

  If not, I suppose one could argue that each wishbone is so lightly loaded that the hinge strength won't matter, and that the double-frame system is always going to create an ideal shape, whereas a batten will curve differently in different wind strengths.

  But I still like thinking about a system without a hinged joint.

       - Mike
 
 
Rudolf vd Brug wrote:

 

HI Mike,

 

From what I understand the wishbones are as little and loosely connected to the mast as possible.

The latest version wishbones have a sort of brace on front of the mast, that's all. Windward side rests against the mast. 

http://wharrambuilders.ning.com/profiles/blogs/sailing-with-pha-tiki-30-n119-1 look about 5/6ths down the blog. There are a lot of photos but this one shows the inside of the sail, the wishbones have red spiral wound tubes to protect the mast.

With type of rig you don't want to add things/ropes or whatever, you try to loose as much stuff as possible.

A shunting schooner doesn't seem very handy witth this rig, I agree. It might not be a very good rig for shunting at all as the sheets may get tangled when shunting. A tacking boat only has one set of sheets, but two sets may cause trouble.

I know of at least one (small) shunting proa using a junck rig. So it can be done.

The multiple sheets are the reason the loads are small, replacing them for a boom brings us to the high loaded rig we already had.

Battens could be composite but probably at great cost as there are moving parts, so dimensions are critical.

Wood would be a bit heavier but much cheaper. I don't see rot as an issue here.

The double wishbone as seen in the blog gives a shape that leaves little to ask, in my opinion.

 

regards,

Rudolf

 

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