The design of soft wing sails for cruising

Mark,
Short answer to all your questions: No.
No book; I'm too busy making things and sailing.
Single sided after part to the sail is easier to assemble.
Adjustable cambering lines don't work; they're too stretchy.
There isn't going to be a mizzen, just one larger single sail.

The construction of the carbon spars is nearing completion, and sailmaking will commence soon.

 

Hi David,
Still trying to decide if I'm going to take on such a project...
Question...
What is the reason to use the Mustang cloth or the other one?
Why not use sailcloth? Is it cost based? Of is there another reason?

 

Soft cruising Dacron sailcloth can be used. I used Richard Hayward's Sunwing http://www.heathcoat.co.uk/marine for my last wingsails. It's UV protected, and better value than others that are not so protected.

Mustang (also Odyssey III) is preferred for junk rig and derivatives because it is soft, and reefs and furls better than Dacron sailcloth; it is a cover material, and so needs no extra covering to protect it when not in use; and is usually less expensive than Dacron sailcloth.

 

Is it stretchy?
Why is it not typically seen used on Marconi style sails?

 

Matt Sheahan has written about the Beneteau wing for Yachting World:
http://www.yachtingworld.com/blogs/matthew-sheahan/536493/beneteau-s-wingsail
On YouTube:
http://www.youtube.com/watch?v=H1cEFP_H4Rk&feature=youtu.be

 

It's stretchier on the bias, but reasonably stable along the threadline. Bermudan/Marconi sails need minimum stretch in all directions, so they need a tightly woven cloth with a resin filled weave. Junk sails and derivatives do not need this. The battens distribute the loads across the cloth, and the battens are sheeted to further distribute the loads. Junk sails have been made from Polytarp, Tyvek, nylon bag-making cloth etc, on a very minimal budget. Of course, some of those don't last long in UV exposure.

 

Just to show that I haven't been idle, here's a photo of the carbon fibre battens, hinges and noses, and a photo of the yard under construction.

 

Keep up the GREAT work David!
This was sent solely to cheer you on.
Can't wait to see your finished product!

 

That's a nice job, David ! I'm sure this will be a good rig !
I hope to see the result on Tystie ... quickly...

 

Dear David,
Thanks for your reply, as short as is deserved.
You can tell I am a coastal sailor (so far), and do not straight away test my thoughts against - 'what will happen when things go wrong, in a rising gale and lee-shore, at night'
Is your single wing-sail going to be going to be smaller than the previous junk sail? (which always looked twice the size I would like to handle)
When you have time, it would be interesting to know your techniques used in moulding the battens.
Look forward to seeing progress, the finished article, and of course hearing how she performs.
cheers Mark

 

Here's another soft wing design;

http://www.onesails.com/wingsails.php

 

Sneek preview

David is up and sailing -see the JRA web-site.

Well done.

 

That can't be possible in practice.

I assume you are running with an infinite aspect ratio.

Try an aspect ratio closer to what would be achievable on a sail and see what happens.

 

Didnt see them running with a reef or two

 

Some early photos: