Subject: Re: [harryproa] Re: sailing Elementarry
Date: 1/24/2006, 9:41 PM
To:, Mike Crawford

Quoting Mike Crawford <>:

 You make good points with respect to stays and headsails.  However,
one could also make the case that technological developments in the
past fifteen years have made stays and headsails less important than
they used to be.

 Arguments for a wishbone boom, unstayed, wingmasted una rig (in
either a single or schooner setup):

 - It's common for boats competing for the speed record to lack a
headsail, and instead use a variation of an unstayed, wingmasted,
shaped main.

 - The speed record current is owned by a windsurfer using a wishbone
una rig.  Granted, Maynard uses a planing board the size of a large
spoon, but he's still using an una rig.

 - A lower speeds, Wyliecat boats (catboats that use a single
wishbone-boomed una rig) have beaten larger boats upwind, when many
people would argue that a headsail will really help.

 - The una rig, especially if nicely tensioned, presents a very
efficient swept back profile that works well without a headsail.

 - Stays generate a surprising amount of drag without contributing
anything to forward motion.  While a portion of a flexble unstayed rig
will also generate drag when the rig flexes leeward, it will pop right
back into generating lift once a gust passes.

 - The wishbone una rig is particularly adept at generating lift, and
should require relatively light winch loads unless running.  With the
sail being self-vanging, the only load on the mainsheet is that which
is required to pull the sail just past the point where it luffs.

 - With only a boom tensioner and a mainsheet, the wishbone una
requires less time and effort to achieve optimal sail shape.  Unless
you have a full crew to pull strings all the time, the simpler design
is likely to enhance speed over the course of a race.

 - The ability to fly the windward hull is actually much more
critical to reducing overall drag than extra sail area or stays.  But
keeping that hull airborne, or just skimming the water, is a delicate
balancing act.  In this scenario, you're much more likely to be able
to hold that balance with a rig that can absorb gusts than with a rig
that doesn't give at all.

 - The lower center of effort on a schooner una rig, as compared to a
taller easyrig, will likely allow it to generate more lift for the
same heeling moment.  Given that both boats use two sails, and a
stayed easyrig will have some additional drag of its own, the lift to
drag ratio of the schooner rig will probably be equivalent or better.


 With that said, I do love the easy rig -- it's hard to dislike a rig
that's so darn easy to sail.

 It's just that any boat in my future plans needs to fit under 65'
bridges, and a 64' easy rig on a boat the size of the visionarry isn't
going to give me the light wind performace I'd like.  Thus, I've
adopted a schooner rig with wishbone-boomed mains as my new dream, and
have in the process become quite a fan of the una rig.

 - Mike
I agree with pretty much everything Mike has said here.
As soon as someone will give me A$250K for XL2 I will start on a 50' Harry with
unstayed schooner rig with wishbones, fixed spade rudders, tiller steering and
Paul Nudd

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