[MHml] DynaRig, Mast-Aft, Bi-Plane sailing rigs

[Dan Frenette]

You could look at setting one foreword of the other a bit. Some pain in 
moving one of the dagger boards so things balance to each other but this 
would pull the mast out from behind the other mast. The cost shouldn't 
be and issue and it offers some design options to open up a longer 
section in one hull.

Looking at these boats none of them seem to address the fact you don't 
have a traveler to speak of. That is you normally on a multi have a 
traveler 8-20+ feet wide to manage the boom height. You should look at a 
wishbone boom for this. It will unload the main sheet creating a very 
manageable rig.

As far as aircraft engineering goes this would be done on one mast if 
all possible. I'm looking at 2 masts so I can fold the thing together 
and slip into a guest slip.

Performance: well don't know anyone who claims it's fast on a real life 
boat. As for performance running when you are cruising think about using 
2 halyards an just put a squarish sail. Think what you could do with a 
hot knife and a blue tarp for a few bucks. That is you don't want 
straight sides or they will fluter. So you cut the arks into every 
straight edge. A sail made out of spinaches cloth will be lighter and 
stow faster but it's whatever you want.

I think I spend about 75% of my time sailing to weather. That is the 
places I want to go are always to weather here in LA and going there I'm 
sailing early read going slow. Coming home I wait until the wind picks 
up so a 4+ hour sail over is 1.5 hours sailing home.

On a multi you spend the other 25% of the time with the wind on the 
beam. I have not modeled what moving the mast 6' vs 10' will mean in 
beam reaching but a shadowed sail is going to give more drive than a 
stalled sail. Running is a bit of a myth for coastal cruising. The land 
people have time tables you (read you guest) want to meet to get a slip, 
wash the boat off before sun down, or get dinner or ...
So when you're going down wind you have the option to heat the boat up 
or motor sail. A boat load of guests and shore boats lends itself to 
motor sail aka pulling the apparent foreword. This is realistically how 
I've spent my sea time over the last 19 years on this boat more years on 
other boats before that.

Does this help explain why this rig isn't so common?

Dan Frenette



brian eiland wrote:
> I recently wrote this letter in response to an inquiry I had on a few sailing
> rigs I've promoted.
> _____________________________________________________ 
> 
> SUBJECT: DynaRig, 40-ish Catamaran motorsailer 
> 
snip...