Subject: Re: [harryproa] Re: Gaff easyrig?
From: Mike Crawford
Date: 3/25/2009, 1:30 AM
To: harryproa@yahoogroups.com.au


  It's definitely true that the max heeling moment is likely to come during a close reach.  I should have said the max heeling moment during the shunt, which begins when you've already scrubbed speed and begun to let off the sail, and ends when you start sheeting on in the other direction.  The apparent wind is roughly equal to the true wind in this case.
 
  During the shunt, then, the period where the full sail area is projected to windward is going to be the max heel, and the boat won't be able to translate any of that force into forward motion. 

  As noted, this only happens for a short period of time.  But I'd rather have a rig that goes to zero in the middle of a shunt, when there's no steering control, and also goes to zero when untended.

  How much of an issue this is probably depends largely upon how you use the boat.

  I spend most of my time daysailing singlehanded in an overpowered multihull (SA/D of 50 to 60, depending upon crew weight).  What I'd love to do is have a boat that has this much power, or even more, but is even safer and more controllable.

  Thus, the ability to go to complete neutral at any instant, and have the sails stay that way for minutes at a time, would be a dream. 

  This means that no matter how high the wind, or how much it increases while you're out, you can stop, drink, pee, or reef the sails, singlehanded, without having to worry about going over, or stressing the boat, while your hands are off the tiller and sheets.

  That may or may not be a selling point if you race with crew, but it's something to seriously consider if you're alone or cruising.

---
 
  I share your hope that someone tests and proves an economical, easily-reefed dyanarig for a few years on a cruising boat.  Or any dual-skinned full wing sail, for that matter.  I keep scouring the net, and people keep claiming to have solved the problem, but most solutions either don't reef well, use hydraulics and/or complex controls, or both.

  I'm just not adventurous enough to be the one testing the various configurations.

        - Mike

 
  Gardner Pomper wrote:

Thanks for the PDF file link. I had not seen that file before. I think I miss a bunch of stuff that gets into the files area by not checking it often enough.


I do remember seeing todd's videos and he made a good case by actually sitting the model with the dynarig facing the wind and it just floated downwind. Seeing that, I think I question the "max heeling moment" portion of the PDF. It might be that just because the max sail area is exposed to the wind, that it is not the maxd heeling moment. I know that if you are on a monohull, you heel over alot more on a close reach than you do on a broad reach, even if you sheet the sails in flat. Because you lose the airflow around the sails, the boat pops upright again.

I do, however, agree on the complexity issue. I expect that I will end up with an easyrig, unless I need the sail area provided by a schooner rig. I just keep hoping that someone will hop in here saying "I have been using the dynarig on my boat for 3 years and it is really simple because of ... " <grin>

- Gardner

On Tue,