-When I was playing around with a monocoque small Harr 7m/5m 2.5m wide
with a foldout cockpit, I considered a Ballestrom rig on the lw side
of the ww hull, the monocoque structure providing support. I also
considered an assymetric lw hull to provide lift. The combination came
pretty close to balanced on over a small range of wind strength and
heading. It would be a bit difficult to maneuver body weight enough
for the fine adjustment, so I considered a small rudder that could
steer forwards, or backwards, hung off one end of the large oval
beam(remember monocoque construction, effectively making the structure
one big beam, reinforced to take particular stresses).. I then
considered a schooner rig on the ww side of the ww hull, and
theoretically it also comes very close to balancing with no
underwater appendages. Fine control can then be done with sails alone.
The stresses seemed reasonable and the construction weight about 270kg.
The schooner rig in this position could easily be integrated int0 the
present configuration, but you need the fold out cockpit to allow
sheeting that allows weather cocking of the rig if caught aback and
maybe a small hull underneath for extra bouyancy if you had a heavy
crew and the wind dropped suddenly.
I considered the effect of windage and comfort of the cockpit, but a
small cuddy and having the cockpit high enough to see over the cabin
roof and it seems plausible and would be better than a tri hull
dangling out there.
I then considered induced drag on a low aspect hull against a high
aspect foil and I thought there is nothing really wrong with the
present configuration.
Robert
-- In harryproa@yahoogrou
>
> It seems that the crab claw moves faster in video
> showing balestron and crab claw side by side. Not big
> difference but that's how it looks on the video.
>
> I agree totally that proa rig needs new thinking. All
> traditional solutions have their problems. Combination
> of some features may bring the best solution.
>
> I agree that staysail only rig has a lot of merit in
> proa. Off the self products, easy to use furling
> sails, good power are all very good properties.
> Structurally the mast to windward rig will produce
> large forces on the boat. Heavy compression and
> bending forces will be the result, which will require
> stronger structure. Is it worth it? I don't know.
> Experiments will tell.
>
> Arto
>
>
> --- tsstproa <bitme1234@.
>
> > In the video
> >
> >
> http://youtube.
> >
> > The easy rig and claw on harry style model was same
> > day testing.
> > Test in roughly the same wind conditions. Notice at
> > the end of video
> > a little larger sail on a deep vee hull form proa ,
> > speed, wake and
> > the freeness in which it truly flies through water
> > and wind.
> >
> > I think in seeking super high pointing ability at
> > wind speed or
> > better from a more traditional western rig ex. sloop
> > type or similar
> > you're going to need a large high buoyant LWH. At a
> > size equivalent
> > as large as or larger than a traditional Pacific
> > Proa main hull. The
> > only way I see getting around this is with a none
> > traditional rig in
> > both senses. Not pacific tradition or western
> > tradition. Not saying
> > this is a solution but just my attempt at the
> > problem.
> >
> > http://youtube.
> > http://youtube.
> > http://youtube.
> >
> >
> > In the clips above the approach may seem complicated
> > and not proven
> > to heavy etc.... all the above and more from
> > skeptics. But an easier
> > solution that some maybe able to wrapped the head
> > around is the mast
> > aft concept and having stay sails. But instead of
> > mast aft, have
> > mast to weather on a proa configuration set at
> > determined distance
> > with stay sails at each bow on roller furling. You
> > don't get the
> > flexibility of the Aframe rig but close enough and
> > with proven
> > equipment all ready on the market. Except possible
> > sail design for
> > stay sails on this type of craft.
> >
> > Todd
> > --- In harryproa@yahoogrou
> > Hakkarainen <ahakkara@>
> > wrote:
> > >
> > > Todd,
> > >
> > >>
> > > But on to the subject.
> > >
> > > I fully agree with your ideas on placing rig CoE
> > > forward to make sail balance better. The reports
> > on
> > > lot of pressure on aft rudder have made me think
> > of
> > > alternative rigs to easyrig. The crab claw and
> > gibbons
> > > seem to work well in smaller proas being effective
> > > rigs and placing sails forward to bow, but scaling
> > > them up to harry or visionarry size seems quite
> > > problematic.
> > >
> > > All my sailing experience tells me that boat
> > should be
> > > well balanced. Easyrig seems very easy to handle
> > but
> > > the rig/rudders combination doesn't seem balanced
> > to
> > > me. Reports on the heavy pressure on aft rudder
> > > indicate that this is the case. Having better
> > balance
> > > should also help to improve performance by
> > reducing
> > > the forces needed to counter the forces caused by
> > > unbalance between sails and foils. In greater
> > speeds
> > > this could be quite a big factor.
> > >
> > > What worries me regarding the crab claw and
> > gibbons is
> > > lack of knowledge and experience on those. That is
> > why
> > > I was so interested in your experiments. And
> > handling
> > > of those rigs with crew of one or two persons may
> > be
> > > too much.
> > >
> > > But I guess it takes considerable amount of
> > testing
> > > and trial & error to get it right. I'm glad there
> > are
> > > others gathering experience and information too.
> > >
> > > Arto
> > >
> > > --- tsstproa <bitme1234@> wrote:
> > >
> > > > Okay
> > > > ****
> > > >
> > > > To judge performance at that scale would be way
> > over
> > > > my head at
> > > > such a small scale. I use models for simply
> > testing
> > > > the effects of
> > > > balance from sail COE positioned in diferent
> > > > locations on different
> > > > hull type proa configurations. To which will
> > give
> > > > best forward drive
> > > > with least amount of effort and best helm
> > balance.
> > > >
> > > > Rig types for specific proa configurations.
> > > > I see in model test on harry type configuration
> > > > (Meaning low draft
> > > > hulls with weight to windward using deep
> > boards)a
> > > > better more narrow
> > > > windward performance range from The easy rig
> > > > compared to the crab
> > > > claw rigged on the same harry type model. But I
> > > > think thats only due
> > > > to the easy rigs placement of the rigs COE being
> > > > back further and
> > > > relying on the single replaced longer rear board
> > to
> > > > counter sail
> > > > force. Same harry type model with claw balances
> > with
> > > > both boards
> > > > down or with just the rear down. Crab claw rig
> > had
> > > > such netrual helm
> > > > I had to set steering boards to make proa go up
> > wind
> > > > which it did
> > > > well but needing input to do it with both boards
> > > > down. Single board
> > > > down cause just enough weather helm to get model
> > up
> > > > wind. But didnot
> > > > seem as efficient as easy rig or as well as
> > > > traditional hull proa
> > > > configuration with crab claw rig.
> > > >
> > > > Notice in this video with harry type hull
> > > > cinfiguration it is with
> > > > the old shorter boards. The 85 sq'' orange claw
> > sail
> > > > balanced why
> > > > better than the the 50 ish sq'' sail on the easy
> > > > rig. with the easy
> > > > rig you can see the extra bit of weight about
> > 1/4 oz
> > > > of sand on the
> > > > rear of lwh to keep model from round up and back
> > > > winding.
> > > >
> > > >
> > >
> >
> http://youtube.
> > > >
> > > > So I guess the question would be how are you
> > will to
> > > > gain your
> > > > performance.
> > > >
> > > > I personally think adapting modern technology to
> > > > mimic tradtional
> > > > methods in rigs felxablity. Is one way in
> > advancing
> > > > proa technology.
> > > > look at clip below for an example.
> > > >
> > > > http://youtube.
> > > >
> > > > In the clip above: Thats a 45% larger sail area
> > than
> > > > the old 50ish
> > > > sq'' easy rig sail on old shorter leeward hull
> > with
> > > > the old short
> > > > baord sailing pretty balanced. Hope this gives
> > you
> > > > some idea.
> > > >
> > > > Look in photo's under Square Harry. for lwh
> >
> === message truncated ===
>
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