--- In harryproa@..., "Todd" <ktsrfer@m...> wrote:
> --- In harryproa@..., "proaconstrictor"
> <proaconstrictor@y...> wrote:
> >
> > The pacific proa isn't generaly highly stable when flying a hull,
> so
> > it isn't going to be any faster for lack of drag.  Also, as it
> cants,
> > it looses both stability and sailing efficiency.
>
> I disagree. With numbers and design

Sounds good.  and the numbers and designs would be...

you can make the hull stable when
> flying the ama. Maybe not as stable as if both ama and vaka were in
> the water

Yeah, but that was the question...

but stable enough to fly the ama long enough to make a
> difference

It certainly makes a speed difference for the boat that is sialing
along nicely with it's ama out of the water, but if one ramps up the
horsepower, this same boat is going to hit it's pod, while the HP is
going to hardly notice.

. To my limited knowledge drag is everthing less the
> better. Check out Sail november 10 issue 2003 page 68. aw yeah lean
> an mean.
>
> So you have a long lean high p/c high boauyant lee hull and a wide,
> shorter in length, short in performance windward hull vs the
leehull.
> Why doesn't the shorter hull limit the leehull?

Everything limits everything.  This is where my you gotta decide
point comes in.  Take the Harryproa, what is this, a 40 footer, or a
28 footer?  In the HP's case, it make some sense to look at say the
40 footer as an F27 sized boat with a 40' LOA because the
accomodation length, and saiplan are in a hibrid comparison closer to
what that shorter boat would offer, than a longer 40 footer.  In that
sense, you have a reasonably low drag main hull, and a very efficient
long hull with a big sled effect to it.  It isn't a mater of the
longer hull being slowed down by the shorter one, it is a mater of
that one long hull being an efficient piece of engineering in
comparison to amas of say 26 feet.  If what you had was a catamaran
with the numbers of a 40 footer, but just one short fat hull, then
you would have a problem, but the numbers on displacement etc...
don't sing out 40 foot cruising multi, this is a pretty small boat.

Since there are as yet few people who have sailed an HP, it's hard to
know whether the exact proportion of the hulls is perfect.  Rob has
said that he doesn't rule out any comaparative hull ratio.  I don't
consider the equal length proa to be a different animal, in fact in
an area of lakes, where perhaps big waves are not so prevalent, it
might be more reasonable to trailer a 27 footer with a 27' lee ama.
Maybe it would be possible to make a great Harryproa ith a razor thin
windward hull, basicaly the same as the lee hull, but with the same
kind off accomaodations on it.  You would end up with a narrow
walkway, and a wave piecing effect.

One thing that is hard to calc is that as you really press down on
the lee hull, and are ripping along, you have unweighted the WW hull,
how much does such a hull, unweighted drag?  Does it ever ballance
out where such a hull really doesn't drag much?  Not sure.

>
> Todd
>
>
> >
> > The right approach to the lee Harry hull is to ensure it has
> > sufficient displacement not to drag too much in any operating
> > environment.  Which is why it is long, very high PC, high
bouyancy,
> > and fine.
> >
> > When comparing an HP to an equal length HP, the main issue is
what
> > are the numbers.  Is it the lee or windward hull on the HP that
is
> > the same length as the Equal length HP.  The answer makes a huge
> > difference in the comparability.

Dave,

The teleflex is a possibility but has similar issues to hard wired electrical
control.  There is about + & - 165 degrees of rotation on the boom so the
cables electrical or mechanical have to flex constantly  with a significant
amount of slack for the wrap.  Boom is limited to 330 degrees due to stays
from the mast top.  To minimize the kink probably would have to route the
cable from mast base up to the yoke.  Turn the yoke vertical so the ram/
cable can work easiest.

The electrical power is really minor, 99.99% of the time the control circuit is
idle with only about 100ma draw for communication.   A small 12V AGM
battery delivers  15 amp-hours before reaching 40% discharge or at least 6-7
days.  The current draw for a DC drive might be 10 amps, but only for 10-20
seconds to adjust the vane.  At all other times the gearbox/ worm drive keeps
the vane at the same adjusted angle.  Essentially the drive works about as
often as you might shunt or change sail trim each day.  Easy for solar to keep
up with that demand.

Thanks for the cable suggestion.  I'll look at how much slack that will take and
how to control the extra cable to prevent kink.  Have to rig up a gearbox at
the helm end versus trying to deal with gears at the ram end of the cable.
The cable has limits on extension so makes sense to do it that way.

Regards,

JT
--- In harryproa@..., Dave Howorth <Dave.Howorth@a...>
wrote:
> jjtctaylor wrote:
>
> >Vanes auto adjust the boom for proper wind angle.  Control lines
> >from the helm to the vane are impractical cause of the boom
> >movement.  Control lines from the helm to the mast and then to
> >the vane also has problems with correcting the precession
> >angle of the boom movement on the vane angle.
> >
> >I have looked around for bluetooth communication to a DC
> >stepper motor drive controller.  But that stuff is still in engineering
> >infancy.  Lots of robot builders tinkering but no tested and
> >supported products.  The marine industry in general has not
> >embraced wireless the connection at all.  Looking for alternative
> >ideas to manage vane angle as a single handed sailor.  The
> >idea is to control the vane angle wirelessly using a stepper
> >motor & gearbox to a rudder yoke.  Power is provided by an AGM
> >12V battery recharged by solar cells.  Essentially entirely self
> >contained on the boom.  No wires at all.
> >
> >If the boat heading is on autopilot and the vane autoadjusts the
> >boom angle, guess it would be time for lunch.   Simple solutions
> >are better, but it needs to be efficient.  I can always put the drive
> >controller inside the LW hull and run wires out to the boom, but I
> >know the wires will eventually fail due to boom movement.  Self
> >contained seems more elegant.
> >
> >
> If you're going to go wireless, then a strong contender for the
> communications is surely a normal radio remote control, as used on model
> yachts?
>
> I'm impressed if solar cells will provide enough power - I'd guess a
> wired system with slip rings and/or multiple flexible, replaceable
> linkages at the mast-boom joint would be more reliable?
>
> But personally I'd be looking for a mechanical system - could you not
> use a morse/teleflex cable for the tricky part to allow for mast/boom
> movement, and then regular 'string' for the rest?
>
> Cheers, Dave

> From: "Todd" <ktsrfer@...>

> I disagree. With numbers and design you can make the hull stable when
> flying the ama. Maybe not as stable as if both ama and vaka were in
> the water but stable enough to fly the ama long enough to make a
> difference. To my limited knowledge drag is everthing less the
> better. Check out Sail november 10 issue 2003 page 68. aw yeah lean
> an mean.

  Ya but... as the windward hull starts to fly the stability starts to drop.
No magic here. Once the boat starts to heel the righting moment is reduced.
This is true of all multihulls. As opposed to monos that gain stability
through heeling by moving the ballast off centre.

  I'm slowly starting to see the reasoning behind a ballasted proa. Malcom
will be so pleased! ;-) But, man, the complexity of all the gear.


> So you have a long lean high p/c high boauyant lee hull and a wide,
> shorter in length, short in performance windward hull vs the leehull.
> Why doesn't the shorter hull limit the leehull?

  I would imagine it's a drag thing. The long lee hull will have (lets call
it a drag factor or DF) a DF of 10, which is a totaly made up number. The
shorter and fatter windward hull will have a similar wetted surface to the
longer and leaner lee hull and proably a similar DF of 10.5, or whatever.

  With my own tacking outrigger I can't tell the difference between one tack
and the other. Which I still find a little odd.

RonB.

  Snowed in, lovin it.

--- In harryproa@..., "proaconstrictor"
<proaconstrictor@y...> wrote:
>
> The pacific proa isn't generaly highly stable when flying a hull,
so
> it isn't going to be any faster for lack of drag.  Also, as it
cants,
> it looses both stability and sailing efficiency.

I disagree. With numbers and design you can make the hull stable when
flying the ama. Maybe not as stable as if both ama and vaka were in
the water but stable enough to fly the ama long enough to make a
difference. To my limited knowledge drag is everthing less the
better. Check out Sail november 10 issue 2003 page 68. aw yeah lean
an mean.

So you have a long lean high p/c high boauyant lee hull and a wide,
shorter in length, short in performance windward hull vs the leehull.
Why doesn't the shorter hull limit the leehull?

Todd


>
> The right approach to the lee Harry hull is to ensure it has
> sufficient displacement not to drag too much in any operating
> environment.  Which is why it is long, very high PC, high bouyancy,
> and fine.
>
> When comparing an HP to an equal length HP, the main issue is what
> are the numbers.  Is it the lee or windward hull on the HP that is
> the same length as the Equal length HP.  The answer makes a huge
> difference in the comparability.

jjtctaylor wrote:

>Vanes auto adjust the boom for proper wind angle.  Control lines
>from the helm to the vane are impractical cause of the boom
>movement.  Control lines from the helm to the mast and then to
>the vane also has problems with correcting the precession
>angle of the boom movement on the vane angle.
>
>I have looked around for bluetooth communication to a DC
>stepper motor drive controller.  But that stuff is still in engineering
>infancy.  Lots of robot builders tinkering but no tested and
>supported products.  The marine industry in general has not
>embraced wireless the connection at all.  Looking for alternative
>ideas to manage vane angle as a single handed sailor.  The
>idea is to control the vane angle wirelessly using a stepper
>motor & gearbox to a rudder yoke.  Power is provided by an AGM
>12V battery recharged by solar cells.  Essentially entirely self
>contained on the boom.  No wires at all.
>
>If the boat heading is on autopilot and the vane autoadjusts the
>boom angle, guess it would be time for lunch.   Simple solutions
>are better, but it needs to be efficient.  I can always put the drive
>controller inside the LW hull and run wires out to the boom, but I
>know the wires will eventually fail due to boom movement.  Self
>contained seems more elegant.
>
>
If you're going to go wireless, then a strong contender for the
communications is surely a normal radio remote control, as used on model
yachts?

I'm impressed if solar cells will provide enough power - I'd guess a
wired system with slip rings and/or multiple flexible, replaceable
linkages at the mast-boom joint would be more reliable?

But personally I'd be looking for a mechanical system - could you not
use a morse/teleflex cable for the tricky part to allow for mast/boom
movement, and then regular 'string' for the rest?

Cheers, Dave

--- In harryproa@..., "Todd" <ktsrfer@m...> wrote:
>  Great Info thanks. With two hulls in the water as opposed two
flying
> the windward hull on the pacific proa there has two be a difference
> in speed. Is this part of the sacrafice for stability ? Can you
make
> up the speed by using a larger sail plan and hull shapes 1/16 or
> greater? If so how much larger sail plan and is it possible to over
> power the leeward hull? I think Terho eql 7 had experienced
somthing
> like this in strong winds and chop or is this just a matter of
> reefing?
>
> Todd

The pacific proa isn't generaly highly stable when flying a hull, so
it isn't going to be any faster for lack of drag.  Also, as it cants,
it looses both stability and sailing efficiency.

The right approach to the lee Harry hull is to ensure it has
sufficient displacement not to drag too much in any operating
environment.  Which is why it is long, very high PC, high bouyancy,
and fine.

When comparing an HP to an equal length HP, the main issue is what
are the numbers.  Is it the lee or windward hull on the HP that is
the same length as the Equal length HP.  The answer makes a huge
difference in the comparability.

WE are still kicking around ideas on how to get  adequate force/
power out of the sails without busting my height limit of 64 ft.

Rob is going to get some prices from a sailmaker to test
wingsails for control and performance.  It's not rocket science but
there are some major design issues.  Lots of effort out there but
there has been tremendous difficulty in making it functionally
advantageous.   I won't dwell on the LIST of design shortfalls
from previous efforts.  Suffice there is a wealth of failures.

The balestron rig fixes many of the basic design issues but not
all.  One issue that has frustrated almost all efforts except those
with deep pockets like the "Walker Wingsail" has been wind to
sail angle.   The problem is higher performance sails including
wingsails narrow the functional window of proper sail angle to
half or less than a conventional sail.  Sea state, rudder
deflection, wind changes contribute to either loss of proper wind
sail angle (power drop) or at worse, drag and sail luffing.

Those with deeper pockets use computer control of trim tabs or
sail rudders (vanes).   A vane can be affixed to the downwind tip
of the balestron mainsail boom.  There are issues with vanes,
but what is needed is control capability from the helm to the
vane.  Vanes make the boom "live" as there are NO sheets.
Vanes auto adjust the boom for proper wind angle.  Control lines
from the helm to the vane are impractical cause of the boom
movement.  Control lines from the helm to the mast and then to
the vane also has problems with correcting the precession
angle of the boom movement on the vane angle.

I have looked around for bluetooth communication to a DC
stepper motor drive controller.  But that stuff is still in engineering
infancy.  Lots of robot builders tinkering but no tested and
supported products.  The marine industry in general has not
embraced wireless the connection at all.  Looking for alternative
ideas to manage vane angle as a single handed sailor.  The
idea is to control the vane angle wirelessly using a stepper
motor & gearbox to a rudder yoke.  Power is provided by an AGM
12V battery recharged by solar cells.  Essentially entirely self
contained on the boom.  No wires at all.

If the boat heading is on autopilot and the vane autoadjusts the
boom angle, guess it would be time for lunch.   Simple solutions
are better, but it needs to be efficient.  I can always put the drive
controller inside the LW hull and run wires out to the boom, but I
know the wires will eventually fail due to boom movement.  Self
contained seems more elegant.

Regards,

JT

Great Info thanks. With two hulls in the water as opposed two flying
the windward hull on the pacific proa there has two be a difference
in speed. Is this part of the sacrafice for stability ? Can you make
up the speed by using a larger sail plan and hull shapes 1/16 or
greater? If so how much larger sail plan and is it possible to over
power the leeward hull? I think Terho eql 7 had experienced somthing
like this in strong winds and chop or is this just a matter of
reefing?

Todd

--- In harryproa@..., "rob denney" <proa@t...> wrote:
> G'day,
>
> The weather hull waterline beam is a function of the length.  No
less than
> 1:10.  Beam overall is limited by structural and aesthetic
concerns, rather
> than handling ones.  However, with all the weight in the windward
hull, it
> will be much narrower than a Pacific proa of similar righting
moment.
> There must be a steering limit on beam over all and on weight in the
> windward hull, but we have yet to reach it.  If we do, it is easily
> corrected by raising the bow rudder during a shunt.
>
> The underwater plane of the two hulls does not appear to be
important.  I
> have not done any tank tests, but have used a variety of different
hull, and
> it has not made any apparent difference.
>
> More drag on the windward (or leeward) hull does not appear to be a
problem,
> any more than it is on a cat with a hull flying, or a tri with one
(or two)
> hulls flying.
>
> Any problems of this nature will show up during a shunt.  For this
reason, I
> think large rudders and no fixed foils are important.  The rudders
can be
> aligned to the water flow and start steering, where a fixed foil
will stall,
> exacerbating any tendency to luff.  The lack of rocker also helps
in this
> respect.
>
> Whether 2 equal hulls are a better idea is a moot point as unequal
drags has
> not shown up as a problem.  While they would increase the payload,
they also
> add wracking loads to the beams, windage and possibly low speed
drag (during
> shunting) which could be problematic.  On W (12m cat with rig in
one hull,
> single rudder in the other) tacking is better on one tack than the
other,
> but this is due more to the rudder being on the inside of the
turning circle
> rather than the outside.  There is no noticable drag dirrence.
Terho Halme
> has experienced similar handling (albeit only in light air so far)
of his 7m
> equal length hulls harryproa.
>
> Hope this answers the question, if not, please try again.
>
> Regards,
>
> Rob
>
>

G'day,

The weather hull waterline beam is a function of the length.  No less than
1:10.  Beam overall is limited by structural and aesthetic concerns, rather
than handling ones.  However, with all the weight in the windward hull, it
will be much narrower than a Pacific proa of similar righting moment.
There must be a steering limit on beam over all and on weight in the
windward hull, but we have yet to reach it.  If we do, it is easily
corrected by raising the bow rudder during a shunt.

The underwater plane of the two hulls does not appear to be important.  I
have not done any tank tests, but have used a variety of different hull, and
it has not made any apparent difference.

More drag on the windward (or leeward) hull does not appear to be a problem,
any more than it is on a cat with a hull flying, or a tri with one (or two)
hulls flying.

Any problems of this nature will show up during a shunt.  For this reason, I
think large rudders and no fixed foils are important.  The rudders can be
aligned to the water flow and start steering, where a fixed foil will stall,
exacerbating any tendency to luff.  The lack of rocker also helps in this
respect.

Whether 2 equal hulls are a better idea is a moot point as unequal drags has
not shown up as a problem.  While they would increase the payload, they also
add wracking loads to the beams, windage and possibly low speed drag (during
shunting) which could be problematic.  On W (12m cat with rig in one hull,
single rudder in the other) tacking is better on one tack than the other,
but this is due more to the rudder being on the inside of the turning circle
rather than the outside.  There is no noticable drag dirrence.  Terho Halme
has experienced similar handling (albeit only in light air so far) of his 7m
equal length hulls harryproa.

Hope this answers the question, if not, please try again.

Regards,

Rob


----- Original Message -----
From: "Todd" <ktsrfer@...>
To: <harryproa@...>
Sent: Monday, December 29, 2003 8:37 AM
Subject: [harryproa] equal & Harry Proas


> On the two types of proas. What is the recommended water line beam
> width of the weather hull is it a percentage of the lee hull beam
> water line? Is the over all beam distance shorter on the two types
> compared to pacific proas? What are the governing factors for
> determining over all beam and water line beam of each hull? Do you
> want the two hulls to have as close as possible the same under water
> plane? If you have more drag on the weather hull what do you do to
> compensate? Larger dagger /center / leeboards? The greater the drag
> the more it wants to turn to weather?
>
> Todd??????
>
>
> To unsubscribe from this group, send an email to:
> harryproa-unsubscribe@...
>
>
>
> Your use of Yahoo! Groups is subject to
http://au.docs.yahoo.com/info/terms/
>
>
>

On the two types of proas. What is the recommended water line beam
width of the weather hull is it a percentage of the lee hull beam
water line? Is the over all beam distance shorter on the two types
compared to pacific proas? What are the governing factors for
determining over all beam and water line beam of each hull? Do you
want the two hulls to have as close as possible the same under water
plane? If you have more drag on the weather hull what do you do to
compensate? Larger dagger /center / leeboards? The greater the drag
the more it wants to turn to weather?

Todd??????

Thanks Jim,
A very Merry Christmas to you and to all on this list,
Brad

groups.com.au, "jameshanahan" <jameshanahan@y...> wrote:
> Merry Christmas to all and Joy and Peace for the coming year.
> Fair winds as they say,
> Jim

Merry Christmas to all and Joy and Peace for the coming year.
Fair winds as they say,
Jim

G'day,

Thanks for the compliment.

It is indeed a cruising boat and will initially be used up and down the east
coast of Australia.

Regards,

Rob
----- Original Message -----
From: <cateran1949@...>
To: <harryproa@...>
Sent: Monday, December 15, 2003 1:08 PM
Subject: [harryproa] Engineering


> I am impressed by the engineering and construction of the Visionary
> Mark has just put together. Beautiful work. This is a cruising boat?
> Robert
>
>
> To unsubscribe from this group, send an email to:
> harryproa-unsubscribe@...
>
>
>
> Your use of Yahoo! Groups is subject to
http://au.docs.yahoo.com/info/terms/
>
>
>

I am impressed by the engineering and construction of the Visionary
Mark has just put together. Beautiful work. This is a cruising boat?
Robert

G'day,

There is noy much point having a wind mast without the boom rotating
independantly.  It is actually easier to build than locking them together.

We do not employ an aerodynamic engineer, just read a lot of books, talk to
a lot of people and play with a lot of ideas.   The structure is treated far
more seriously, and is engineered by a certified, experienced engineer.

Regards,

Rob
----- Original Message -----
From: <cateran1949@...>
To: <harryproa@...>
Sent: Monday, December 15, 2003 5:49 AM
Subject: [harryproa] Re: Sail Rig Options


> I am starting to feel that it doesn't make much difference, though
> there is probably a bit of horses for courses. My suspicion that the
> course is probably closer to the A class in terms of the dynamics of
> the boat, especially with a semi stayed mast.  Is there scope for
> having a wing mast with the ability to rotate with respect to the
> boom with the balestron rig?
> Is the structural engineer of the mast the same person as the
> aerodynamic engineer?
> Robert
>
>
>
>
> --- In harryproa@..., "rob denney" <proa@t...> wrote:
> > G'day,
> >
> > No idea if the price is correct or not, but it has been sitting
> there for 6
> > months, nobody looks like sailing it this year, so maybe.  Give
> Brett a
> > call, I am sure that between $200,000 and $1,000, you will find
> some common
> > ground!  The guy who engineered their masts is also doing ours.
> Spitfire's
> > had to see some pretty huge loads as the boat on foils is very
> wide, and
> > there is allowance for (500 kgs, I think) water ballast.  There is
> very
> > little bury, which would not have helped.  A comparison would be
> nice, but
> > there are too many variables between this boat and others for it to
> be
> > meaningful.  A class cats, which can have either all go for wing
> masts,
> > which may be significant, although Moths (where weight aloft is
> more of an
> > issue) all go for sleeves.  All the high performance skiffs go for
> track and
> > bolt rope, so maybe none of it makes much difference?
> >
> > Regards,
> >
> > Rob
> > ----- Original Message -----
> > From: "Robert" <cateran1949@y...>
> > To: <harryproa@...>
> > Sent: Thursday, December 11, 2003 11:25 AM
> > Subject: [harryproa] Re: Sail Rig Options
> >
> >
> > > --- In harryproa@..., "Rob Denney" <proa@t...>
> wrote:
> > > >  Rumour is he got bored (maybe just scared!), tried to
> > > > sell it, couldn't and gave it back to the builders.  It is now
> > > sitting in
> > > > the yacht club yard alongside some of my old hulls.  Best offer
> > > over a grand
> > > > would probably buy it.
> > >
> > > Is that for real.
> > >
> > > >
> > > > Brett Burville the builder has had a lot of experience with
> > > hydrofoils as
> > > > the first person to get a moth (11' long, 1' wide overcanvassed
> > > dinghy)
> > > > flying.  He also had a smaller version of the Spitfire rig.
> Also
> > > with a
> > > > round mast. When I have chatted with him he has always been
> > > completely open,
> > > > a really nice bloke.  If anyone has any questions, I am sure he
> > > wouild
> > > > answer them.  The Spitfire masts are about 300mm in diameter,
> 12m
> > > long with
> > > > a very steep taper.  I cannot lift the heavy end.  As far as I
> > > know, they
> > > > never played with a fine entry on the mast.  The sail was
> hoisted
> > > in two
> > > > bolt rope tracks, one on each side of the mast.
> > >
> > >
> > >
> > > I miss read the site and was looking at a crosssection of the
> > > crossbeam, not the mast.The twin bolt arrangement apears to be
> > > similar to the Dynarig.  I would certainly be interested in how
> much
> > > better it performs over a 10% wing mast and whether it is worth
> the
> > > hassles.
> > > Do the masts realy have to be that heavy? and there doesn't seem
> to
> > > be much depth of hull to hold them up.
> > > In heavy chop the boat would be comfortable but I wonder about
> doing
> > > 30-40 knots in ocean swell. I think that would scare me.
> > >  Robert
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > >
> > > > Regards,
> > > >
> > > > Rob
> > > > ----- Original Message -----
> > > > From: "Robert" <cateran1949@y...>
> > > > To: <harryproa@...>
> > > > Sent: Wednesday, December 10, 2003 12:22 PM
> > > > Subject: [harryproa] Re: Sail Rig Options
> > > >
> > > >
> > > > > I've had a close lok at the site. The boat certainly goes well
> > > but if
> > > > > you look closely at the picture of the ww side of the sail, it
> > > > > doesn't look very smooth. You can see clearly wrinkles around
> the
> > > > > compression strut vanging the boom. In the section of the mast
> > > they
> > > > > show a fairly fine entry mast but in the talk on the overall
> rig
> > > they
> > > > > talk about a circular section mast.
> > > > > Don't really understand what they are doing. Possibly they are
> > > > > avoiding giving away too much detail, or the fine entry mast
> > > section
> > > > > didn't work.
> > > > > Robert
> > > > >
> > > > >
> > > > > --- In harryproa@..., "jjtctaylor"
> > > <jtaylor412@c...>
> > > > > wrote:
> > > > > > For those in Australia,  and lucky ones in Perth a possible
> > > > > > source for Wing masts using the Dynarig approach is BDG
> > > > > > Marine.   See link:
> http://marine.bdg.com.au/contact.html
> > > > > >
> > > > > > They have been using it on their "spitfire" twin wingmast
> boat.
> > > > > > They have some arrangement with Windrush for a high speed
> > > > > > foil borne cat that also uses this technique.  Somebody has
> a
> > > > > > provisional patent, but not sure who it is.
> > > > > >
> > > > > > It's a place to start if you have interest in trying it.
> > > > > >
> > > > > > JT
> > > > > >
> > > > > >
> > > > > > --- In harryproa@..., "Robert"
> > > > > > <cateran1949@y...> wrote:
> > > > > > > --- In harryproa@..., "jjtctaylor"
> > > > > > <jtaylor412@c...>
> > > > > > > wrote:
> > > > > > > > The Dynawing  introducers, called powerfoils are only
> > > > > > intended
> > > > > > > > on their fixed wing dynafoils for sailboard use.  They
> are a
> > > > > > fixed
> > > > > > > > part of the wing sail.   They are not practical for
> hauling
> > > up
> > > > > 40-
> > > > > > > 50
> > > > > > > > feet on a mast.  They encapsulate the mast itself, so
> > > binding
> > > > > > is a
> > > > > > > > problem.
> > > > > > >
> > > > > > > Could this be overcome with slightly more clearance and
> > > > > > graphite
> > > > > > > lubrication? They already go to 6 or 7m. They don't have
> to
> > > > > > > encapsulate the mast, they can sit forward of it with the
> > > baton
> > > > > > > receivers projecting just past halfway of the mast. I
> can't
> > > see
> > > > > > any
> > > > > > > insurmountable problems, though a lot of cost in getting
> it
> > > > > > right.
> > > > > > > Maybe we should ask the powerfoil people.
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >  They did not employ them with their dynarig effort,
> > > > > > > > hence they have no introducer.  A major flaw in their
> > > > > > execution.
> > > > > > >
> > > > > > > Agreed, it hardly seemed worth the hassle of having a
> double
> > > > > > luffed
> > > > > > > sail without the introducer.
> > > > > > >
> > > > > > > >
> > > > > > > > Seen them stick a a piece of foam for a parabolic
> reshaping
> > > > > > of
> > > > > > > > the mast leading edge.  That is not effective either
> cause
> > > it
> > > > > > > > negates a great portion of the lift  where the
> introducer is
> > > > > > head
> > > > > > > > into the wind and parts the airstream.  That lift is
> > > > > essentially
> > > > > > > lost
> > > > > > > > on the leading edge of your mast without a proper
> > > introducer.
> > > > > > > > The turbulent boundary layer caused by this poorly
> designed
> > > > > > > > nose has to reattach itself some distance down the wing.
> > > > > > > > Doesn't mean there isn't some lift, but the turbulent
> air is
> > > > > > mixing
> > > > > > > > with air at ambient pressure negating big lift
> opportunity.
> > > > > > >
> > > > > > > This is why I was wondering about having a mast with an
> > > > > > introducer
> > > > > > > built in to its shape, and having the mast rotate
> separately
> > > from
> > > > > > the
> > > > > > > boom. I am thinking of building a wing mast for my Jarcat
> and
> > > it
> > > > > > > might be worth trying but I am not sure about who to ask
> for
> > > > > > making
> > > > > > > suitable sails.
> > > > > > >
> > > > > > > >
> > > > > > > > Simple execution does not mean effective.  Reasons for
> few
> > > > > > > > commercial attempts with soft wing sails.
> > > > > > > >
> > > > > > > > JT
> > > > > > > >
> > > > > > > > --- In harryproa@..., "Robert"
> > > > > > > > <cateran1949@y...> wrote:
> > > > > > > > > Elegant simplicity. Does it have a line to the top
> gaff to
> > > > > > > control
> > > > > > > > > twist? Would the top gaff act to some extent as an end
> > > > > > plate?
> > > > > > > > Much as
> > > > > > > > > I like the simplicity, I can't help wanting to fiddle
> > > with it
> > > > > to
> > > > > > > make
> > > > > > > > > it go that little bit better.
> > > > > > > > > How would one of these go with a rotating wing mast to
> > > > > > give
> > > > > > > > finer
> > > > > > > > > entry and control camber? It would probably require
> > > split  or
> > > > > > > > twinned
> > > > > > > > > battens though, and outhaul tension controls to do it
> > > > > > properly.
> > > > > > > It
> > > > > > > > > might be better to go the whole hog and use dynawing
> foil
> > > > > > > > inducers
> > > > > > > > > and their related battens. Or go even further and
> replace
> > > > > > the
> > > > > > > > top
> > > > > > > > > gaff with a batten, enclose the area between the top
> gaff
> > > > > > and
> > > > > > > > the
> > > > > > > > > mast and you have a dynawing.
> > > > > > > > > A problem with all these rigs is how to attach stays
> to
> > > their
> > > > > > > > optimum
> > > > > > > > > position of ~2/3 of the way up the mast and still
> allow
> > > > > > reefing.
> > > > > > > > This
> > > > > > > > > can be overcome with a litle extra weight in
> stiffening
> > > and
> > > > > > > > attach
> > > > > > > > > them higher to the mast or even to the sail.
> > > > > > > > >  I would like to see some boat to boat comparisons of
> the
> > > > > > > > various
> > > > > > > > > rigs on Harryproas, but first we have to get some
> boats
> > > > > > sailing.
> > > > > > > > > Robert
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > --- In harryproa@..., "proaconstrictor"
> > > > > > > > > <proaconstrictor@y...> wrote:
> > > > > > > > > > --- In harryproa@..., "Robert"
> > > > > > > > <cateran1949@y...>
> > > > > > > > > > wrote:
> > > > > > > > > > > Personally I like the idea of a soft wing sail, in
> > > fact I
> > > > > > > quite
> > > > > > > > > > like
> > > > > > > > > > > Wharram's high gaff soft wing
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > Did you catch this?
> > > > > > > > > >
> > > > > > > > > > http://www.themultihull.com/woods/ps1.htm
> > > > >
> > > > >
> > > > > To unsubscribe from this group, send an email to:
> > > > > harryproa-unsubscribe@...
> > > > >
> > > > >
> > > > >
> > > > > Your use of Yahoo! Groups is subject to
> > > > http://au.docs.yahoo.com/info/terms/
> > > > >
> > > > >
> > > > >
> > >
> > >
> > > To unsubscribe from this group, send an email to:
> > > harryproa-unsubscribe@...
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> > http://au.docs.yahoo.com/info/terms/
> > >
> > >
> > >
>
>
> To unsubscribe from this group, send an email to:
> harryproa-unsubscribe@...
>
>
>
> Your use of Yahoo! Groups is subject to
http://au.docs.yahoo.com/info/terms/
>
>
>

Hello Everyone,

Delighted to bring you the latest developments at Harryproa.
http://www.harryproa.com/

It's been two months since the last update so we have quite a few construction
photos from;
   1.. Australia (http://www.harryproa.com/building_Vis/building_Vis_6.htm),
   2.. Finland (http://www.harryproa.com/Arttu/Arttu_2.htm) and
   3.. Holland (http://www.harryproa.com/BlindDate/Jan_8.htm).
Things are beginning to move regarding Elementarry, by the next update we will
have news!
In the mean time we wish you a joyous and peaceful festive season.


     Regards,

         Michele, Rob, and Mark





------------------------------
Michele Balharry
Harryproa Pty. Ltd.
ph: +61 02 6655 2016
fax: +61 02 6655 9994
e-mail: michele@...
web site: www.harryproa.com


[Non-text portions of this message have been removed]

I am starting to feel that it doesn't make much difference, though
there is probably a bit of horses for courses. My suspicion that the
course is probably closer to the A class in terms of the dynamics of
the boat, especially with a semi stayed mast.  Is there scope for
having a wing mast with the ability to rotate with respect to the
boom with the balestron rig?
Is the structural engineer of the mast the same person as the
aerodynamic engineer?
Robert




--- In harryproa@..., "rob denney" <proa@t...> wrote:
> G'day,
>
> No idea if the price is correct or not, but it has been sitting
there for 6
> months, nobody looks like sailing it this year, so maybe.  Give
Brett a
> call, I am sure that between $200,000 and $1,000, you will find
some common
> ground!  The guy who engineered their masts is also doing ours.
Spitfire's
> had to see some pretty huge loads as the boat on foils is very
wide, and
> there is allowance for (500 kgs, I think) water ballast.  There is
very
> little bury, which would not have helped.  A comparison would be
nice, but
> there are too many variables between this boat and others for it to
be
> meaningful.  A class cats, which can have either all go for wing
masts,
> which may be significant, although Moths (where weight aloft is
more of an
> issue) all go for sleeves.  All the high performance skiffs go for
track and
> bolt rope, so maybe none of it makes much difference?
>
> Regards,
>
> Rob
> ----- Original Message -----
> From: "Robert" <cateran1949@y...>
> To: <harryproa@...>
> Sent: Thursday, December 11, 2003 11:25 AM
> Subject: [harryproa] Re: Sail Rig Options
>
>
> > --- In harryproa@..., "Rob Denney" <proa@t...>
wrote:
> > >  Rumour is he got bored (maybe just scared!), tried to
> > > sell it, couldn't and gave it back to the builders.  It is now
> > sitting in
> > > the yacht club yard alongside some of my old hulls.  Best offer
> > over a grand
> > > would probably buy it.
> >
> > Is that for real.
> >
> > >
> > > Brett Burville the builder has had a lot of experience with
> > hydrofoils as
> > > the first person to get a moth (11' long, 1' wide overcanvassed
> > dinghy)
> > > flying.  He also had a smaller version of the Spitfire rig.
Also
> > with a
> > > round mast. When I have chatted with him he has always been
> > completely open,
> > > a really nice bloke.  If anyone has any questions, I am sure he
> > wouild
> > > answer them.  The Spitfire masts are about 300mm in diameter,
12m
> > long with
> > > a very steep taper.  I cannot lift the heavy end.  As far as I
> > know, they
> > > never played with a fine entry on the mast.  The sail was
hoisted
> > in two
> > > bolt rope tracks, one on each side of the mast.
> >
> >
> >
> > I miss read the site and was looking at a crosssection of the
> > crossbeam, not the mast.The twin bolt arrangement apears to be
> > similar to the Dynarig.  I would certainly be interested in how
much
> > better it performs over a 10% wing mast and whether it is worth
the
> > hassles.
> > Do the masts realy have to be that heavy? and there doesn't seem
to
> > be much depth of hull to hold them up.
> > In heavy chop the boat would be comfortable but I wonder about
doing
> > 30-40 knots in ocean swell. I think that would scare me.
> >  Robert
> >
> >
> >
> >
> >
> >
> >
> >
> > >
> > > Regards,
> > >
> > > Rob
> > > ----- Original Message -----
> > > From: "Robert" <cateran1949@y...>
> > > To: <harryproa@...>
> > > Sent: Wednesday, December 10, 2003 12:22 PM
> > > Subject: [harryproa] Re: Sail Rig Options
> > >
> > >
> > > > I've had a close lok at the site. The boat certainly goes well
> > but if
> > > > you look closely at the picture of the ww side of the sail, it
> > > > doesn't look very smooth. You can see clearly wrinkles around
the
> > > > compression strut vanging the boom. In the section of the mast
> > they
> > > > show a fairly fine entry mast but in the talk on the overall
rig
> > they
> > > > talk about a circular section mast.
> > > > Don't really understand what they are doing. Possibly they are
> > > > avoiding giving away too much detail, or the fine entry mast
> > section
> > > > didn't work.
> > > > Robert
> > > >
> > > >
> > > > --- In harryproa@..., "jjtctaylor"
> > <jtaylor412@c...>
> > > > wrote:
> > > > > For those in Australia,  and lucky ones in Perth a possible
> > > > > source for Wing masts using the Dynarig approach is BDG
> > > > > Marine.   See link:
http://marine.bdg.com.au/contact.html
> > > > >
> > > > > They have been using it on their "spitfire" twin wingmast
boat.
> > > > > They have some arrangement with Windrush for a high speed
> > > > > foil borne cat that also uses this technique.  Somebody has
a
> > > > > provisional patent, but not sure who it is.
> > > > >
> > > > > It's a place to start if you have interest in trying it.
> > > > >
> > > > > JT
> > > > >
> > > > >
> > > > > --- In harryproa@..., "Robert"
> > > > > <cateran1949@y...> wrote:
> > > > > > --- In harryproa@..., "jjtctaylor"
> > > > > <jtaylor412@c...>
> > > > > > wrote:
> > > > > > > The Dynawing  introducers, called powerfoils are only
> > > > > intended
> > > > > > > on their fixed wing dynafoils for sailboard use.  They
are a
> > > > > fixed
> > > > > > > part of the wing sail.   They are not practical for
hauling
> > up
> > > > 40-
> > > > > > 50
> > > > > > > feet on a mast.  They encapsulate the mast itself, so
> > binding
> > > > > is a
> > > > > > > problem.
> > > > > >
> > > > > > Could this be overcome with slightly more clearance and
> > > > > graphite
> > > > > > lubrication? They already go to 6 or 7m. They don't have
to
> > > > > > encapsulate the mast, they can sit forward of it with the
> > baton
> > > > > > receivers projecting just past halfway of the mast. I
can't
> > see
> > > > > any
> > > > > > insurmountable problems, though a lot of cost in getting
it
> > > > > right.
> > > > > > Maybe we should ask the powerfoil people.
> > > > > >
> > > > > >
> > > > > >
> > > > > >  They did not employ them with their dynarig effort,
> > > > > > > hence they have no introducer.  A major flaw in their
> > > > > execution.
> > > > > >
> > > > > > Agreed, it hardly seemed worth the hassle of having a
double
> > > > > luffed
> > > > > > sail without the introducer.
> > > > > >
> > > > > > >
> > > > > > > Seen them stick a a piece of foam for a parabolic
reshaping
> > > > > of
> > > > > > > the mast leading edge.  That is not effective either
cause
> > it
> > > > > > > negates a great portion of the lift  where the
introducer is
> > > > > head
> > > > > > > into the wind and parts the airstream.  That lift is
> > > > essentially
> > > > > > lost
> > > > > > > on the leading edge of your mast without a proper
> > introducer.
> > > > > > > The turbulent boundary layer caused by this poorly
designed
> > > > > > > nose has to reattach itself some distance down the wing.
> > > > > > > Doesn't mean there isn't some lift, but the turbulent
air is
> > > > > mixing
> > > > > > > with air at ambient pressure negating big lift
opportunity.
> > > > > >
> > > > > > This is why I was wondering about having a mast with an
> > > > > introducer
> > > > > > built in to its shape, and having the mast rotate
separately
> > from
> > > > > the
> > > > > > boom. I am thinking of building a wing mast for my Jarcat
and
> > it
> > > > > > might be worth trying but I am not sure about who to ask
for
> > > > > making
> > > > > > suitable sails.
> > > > > >
> > > > > > >
> > > > > > > Simple execution does not mean effective.  Reasons for
few
> > > > > > > commercial attempts with soft wing sails.
> > > > > > >
> > > > > > > JT
> > > > > > >
> > > > > > > --- In harryproa@..., "Robert"
> > > > > > > <cateran1949@y...> wrote:
> > > > > > > > Elegant simplicity. Does it have a line to the top
gaff to
> > > > > > control
> > > > > > > > twist? Would the top gaff act to some extent as an end
> > > > > plate?
> > > > > > > Much as
> > > > > > > > I like the simplicity, I can't help wanting to fiddle
> > with it
> > > > to
> > > > > > make
> > > > > > > > it go that little bit better.
> > > > > > > > How would one of these go with a rotating wing mast to
> > > > > give
> > > > > > > finer
> > > > > > > > entry and control camber? It would probably require
> > split  or
> > > > > > > twinned
> > > > > > > > battens though, and outhaul tension controls to do it
> > > > > properly.
> > > > > > It
> > > > > > > > might be better to go the whole hog and use dynawing
foil
> > > > > > > inducers
> > > > > > > > and their related battens. Or go even further and
replace
> > > > > the
> > > > > > > top
> > > > > > > > gaff with a batten, enclose the area between the top
gaff
> > > > > and
> > > > > > > the
> > > > > > > > mast and you have a dynawing.
> > > > > > > > A problem with all these rigs is how to attach stays
to
> > their
> > > > > > > optimum
> > > > > > > > position of ~2/3 of the way up the mast and still
allow
> > > > > reefing.
> > > > > > > This
> > > > > > > > can be overcome with a litle extra weight in
stiffening
> > and
> > > > > > > attach
> > > > > > > > them higher to the mast or even to the sail.
> > > > > > > >  I would like to see some boat to boat comparisons of
the
> > > > > > > various
> > > > > > > > rigs on Harryproas, but first we have to get some
boats
> > > > > sailing.
> > > > > > > > Robert
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > --- In harryproa@..., "proaconstrictor"
> > > > > > > > <proaconstrictor@y...> wrote:
> > > > > > > > > --- In harryproa@..., "Robert"
> > > > > > > <cateran1949@y...>
> > > > > > > > > wrote:
> > > > > > > > > > Personally I like the idea of a soft wing sail, in
> > fact I
> > > > > > quite
> > > > > > > > > like
> > > > > > > > > > Wharram's high gaff soft wing
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Did you catch this?
> > > > > > > > >
> > > > > > > > > http://www.themultihull.com/woods/ps1.htm
> > > >
> > > >
> > > > To unsubscribe from this group, send an email to:
> > > > harryproa-unsubscribe@...
> > > >
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > > http://au.docs.yahoo.com/info/terms/
> > > >
> > > >
> > > >
> >
> >
> > To unsubscribe from this group, send an email to:
> > harryproa-unsubscribe@...
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://au.docs.yahoo.com/info/terms/
> >
> >
> >

The differences in rig are born out of different requirements from the boats in
my opinion.
The only thing these boats have in common is that they all use the wind to power
them.
I also agree that it may make no difference which one they have.
But as all are development classes within a rule, the most efficient(read
fastest)rig for the class should prevail.
All this may have come about because of experimentation.
So by all means experiment
If you always do what you have always done you will always get what you have
always got.
If I may suggest that the reason we are all on this list is we believe it can
all be done better.
Just what constitutes better?
I would suggest better ideas.
An old musician once told me a quotable quote that may be pertinent
"There are no wrong notes in jazz music only poor choices"
Maybe the man who ordered the spitfire just made a poor choice for his
requirements.
I suspect it just scared the shit out of him
Rgs
Tony

   ----- Original Message -----
   From: rob denney
   To: harryproa@...
   Sent: Friday, December 12, 2003 4:45 PM
   Subject: Re: [harryproa] Re: Sail Rig Options


   G'day,

   No idea if the price is correct or not, but it has been sitting there for 6
   months, nobody looks like sailing it this year, so maybe.  Give Brett a
   call, I am sure that between $200,000 and $1,000, you will find some common
   ground!  The guy who engineered their masts is also doing ours.  Spitfire's
   had to see some pretty huge loads as the boat on foils is very wide, and
   there is allowance for (500 kgs, I think) water ballast.  There is very
   little bury, which would not have helped.  A comparison would be nice, but
   there are too many variables between this boat and others for it to be
   meaningful.  A class cats, which can have either all go for wing masts,
   which may be significant, although Moths (where weight aloft is more of an
   issue) all go for sleeves.  All the high performance skiffs go for track and
   bolt rope, so maybe none of it makes much difference?

   Regards,

   Rob
   ----- Original Message -----
   From: "Robert" <cateran1949@...>
   To: <harryproa@...>
   Sent: Thursday, December 11, 2003 11:25 AM
   Subject: [harryproa] Re: Sail Rig Options


   > --- In harryproa@..., "Rob Denney" <proa@t...> wrote:
   > >  Rumour is he got bored (maybe just scared!), tried to
   > > sell it, couldn't and gave it back to the builders.  It is now
   > sitting in
   > > the yacht club yard alongside some of my old hulls.  Best offer
   > over a grand
   > > would probably buy it.
   >
   > Is that for real.
   >
   > >
   > > Brett Burville the builder has had a lot of experience with
   > hydrofoils as
   > > the first person to get a moth (11' long, 1' wide overcanvassed
   > dinghy)
   > > flying.  He also had a smaller version of the Spitfire rig.  Also
   > with a
   > > round mast. When I have chatted with him he has always been
   > completely open,
   > > a really nice bloke.  If anyone has any questions, I am sure he
   > wouild
   > > answer them.  The Spitfire masts are about 300mm in diameter, 12m
   > long with
   > > a very steep taper.  I cannot lift the heavy end.  As far as I
   > know, they
   > > never played with a fine entry on the mast.  The sail was hoisted
   > in two
   > > bolt rope tracks, one on each side of the mast.
   >
   >
   >
   > I miss read the site and was looking at a crosssection of the
   > crossbeam, not the mast.The twin bolt arrangement apears to be
   > similar to the Dynarig.  I would certainly be interested in how much
   > better it performs over a 10% wing mast and whether it is worth the
   > hassles.
   > Do the masts realy have to be that heavy? and there doesn't seem to
   > be much depth of hull to hold them up.
   > In heavy chop the boat would be comfortable but I wonder about doing
   > 30-40 knots in ocean swell. I think that would scare me.
   >  Robert
   >
   >
   >
   >
   >
   >
   >
   >
   > >
   > > Regards,
   > >
   > > Rob
   > > ----- Original Message -----
   > > From: "Robert" <cateran1949@y...>
   > > To: <harryproa@...>
   > > Sent: Wednesday, December 10, 2003 12:22 PM
   > > Subject: [harryproa] Re: Sail Rig Options
   > >
   > >
   > > > I've had a close lok at the site. The boat certainly goes well
   > but if
   > > > you look closely at the picture of the ww side of the sail, it
   > > > doesn't look very smooth. You can see clearly wrinkles around the
   > > > compression strut vanging the boom. In the section of the mast
   > they
   > > > show a fairly fine entry mast but in the talk on the overall rig
   > they
   > > > talk about a circular section mast.
   > > > Don't really understand what they are doing. Possibly they are
   > > > avoiding giving away too much detail, or the fine entry mast
   > section
   > > > didn't work.
   > > > Robert
   > > >
   > > >
   > > > --- In harryproa@..., "jjtctaylor"
   > <jtaylor412@c...>
   > > > wrote:
   > > > > For those in Australia,  and lucky ones in Perth a possible
   > > > > source for Wing masts using the Dynarig approach is BDG
   > > > > Marine.   See link:      http://marine.bdg.com.au/contact.html
   > > > >
   > > > > They have been using it on their "spitfire" twin wingmast boat.
   > > > > They have some arrangement with Windrush for a high speed
   > > > > foil borne cat that also uses this technique.  Somebody has a
   > > > > provisional patent, but not sure who it is.
   > > > >
   > > > > It's a place to start if you have interest in trying it.
   > > > >
   > > > > JT
   > > > >
   > > > >
   > > > > --- In harryproa@..., "Robert"
   > > > > <cateran1949@y...> wrote:
   > > > > > --- In harryproa@..., "jjtctaylor"
   > > > > <jtaylor412@c...>
   > > > > > wrote:
   > > > > > > The Dynawing  introducers, called powerfoils are only
   > > > > intended
   > > > > > > on their fixed wing dynafoils for sailboard use.  They are a
   > > > > fixed
   > > > > > > part of the wing sail.   They are not practical for hauling
   > up
   > > > 40-
   > > > > > 50
   > > > > > > feet on a mast.  They encapsulate the mast itself, so
   > binding
   > > > > is a
   > > > > > > problem.
   > > > > >
   > > > > > Could this be overcome with slightly more clearance and
   > > > > graphite
   > > > > > lubrication? They already go to 6 or 7m. They don't have to
   > > > > > encapsulate the mast, they can sit forward of it with the
   > baton
   > > > > > receivers projecting just past halfway of the mast. I can't
   > see
   > > > > any
   > > > > > insurmountable problems, though a lot of cost in getting it
   > > > > right.
   > > > > > Maybe we should ask the powerfoil people.
   > > > > >
   > > > > >
   > > > > >
   > > > > >  They did not employ them with their dynarig effort,
   > > > > > > hence they have no introducer.  A major flaw in their
   > > > > execution.
   > > > > >
   > > > > > Agreed, it hardly seemed worth the hassle of having a double
   > > > > luffed
   > > > > > sail without the introducer.
   > > > > >
   > > > > > >
   > > > > > > Seen them stick a a piece of foam for a parabolic reshaping
   > > > > of
   > > > > > > the mast leading edge.  That is not effective either cause
   > it
   > > > > > > negates a great portion of the lift  where the introducer is
   > > > > head
   > > > > > > into the wind and parts the airstream.  That lift is
   > > > essentially
   > > > > > lost
   > > > > > > on the leading edge of your mast without a proper
   > introducer.
   > > > > > > The turbulent boundary layer caused by this poorly designed
   > > > > > > nose has to reattach itself some distance down the wing.
   > > > > > > Doesn't mean there isn't some lift, but the turbulent air is
   > > > > mixing
   > > > > > > with air at ambient pressure negating big lift opportunity.
   > > > > >
   > > > > > This is why I was wondering about having a mast with an
   > > > > introducer
   > > > > > built in to its shape, and having the mast rotate separately
   > from
   > > > > the
   > > > > > boom. I am thinking of building a wing mast for my Jarcat and
   > it
   > > > > > might be worth trying but I am not sure about who to ask for
   > > > > making
   > > > > > suitable sails.
   > > > > >
   > > > > > >
   > > > > > > Simple execution does not mean effective.  Reasons for few
   > > > > > > commercial attempts with soft wing sails.
   > > > > > >
   > > > > > > JT
   > > > > > >
   > > > > > > --- In harryproa@..., "Robert"
   > > > > > > <cateran1949@y...> wrote:
   > > > > > > > Elegant simplicity. Does it have a line to the top gaff to
   > > > > > control
   > > > > > > > twist? Would the top gaff act to some extent as an end
   > > > > plate?
   > > > > > > Much as
   > > > > > > > I like the simplicity, I can't help wanting to fiddle
   > with it
   > > > to
   > > > > > make
   > > > > > > > it go that little bit better.
   > > > > > > > How would one of these go with a rotating wing mast to
   > > > > give
   > > > > > > finer
   > > > > > > > entry and control camber? It would probably require
   > split  or
   > > > > > > twinned
   > > > > > > > battens though, and outhaul tension controls to do it
   > > > > properly.
   > > > > > It
   > > > > > > > might be better to go the whole hog and use dynawing foil
   > > > > > > inducers
   > > > > > > > and their related battens. Or go even further and replace
   > > > > the
   > > > > > > top
   > > > > > > > gaff with a batten, enclose the area between the top gaff
   > > > > and
   > > > > > > the
   > > > > > > > mast and you have a dynawing.
   > > > > > > > A problem with all these rigs is how to attach stays to
   > their
   > > > > > > optimum
   > > > > > > > position of ~2/3 of the way up the mast and still allow
   > > > > reefing.
   > > > > > > This
   > > > > > > > can be overcome with a litle extra weight in stiffening
   > and
   > > > > > > attach
   > > > > > > > them higher to the mast or even to the sail.
   > > > > > > >  I would like to see some boat to boat comparisons of the
   > > > > > > various
   > > > > > > > rigs on Harryproas, but first we have to get some boats
   > > > > sailing.
   > > > > > > > Robert
   > > > > > > >
   > > > > > > >
   > > > > > > >
   > > > > > > >
   > > > > > > > --- In harryproa@..., "proaconstrictor"
   > > > > > > > <proaconstrictor@y...> wrote:
   > > > > > > > > --- In harryproa@..., "Robert"
   > > > > > > <cateran1949@y...>
   > > > > > > > > wrote:
   > > > > > > > > > Personally I like the idea of a soft wing sail, in
   > fact I
   > > > > > quite
   > > > > > > > > like
   > > > > > > > > > Wharram's high gaff soft wing
   > > > > > > > >
   > > > > > > > >
   > > > > > > > > Did you catch this?
   > > > > > > > >
   > > > > > > > > http://www.themultihull.com/woods/ps1.htm
   > > >
   > > >
   > > > To unsubscribe from this group, send an email to:
   > > > harryproa-unsubscribe@...
   > > >
   > > >
   > > >
   > > > Your use of Yahoo! Groups is subject to
   > > http://au.docs.yahoo.com/info/terms/
   > > >
   > > >
   > > >
   >
   >
   > To unsubscribe from this group, send an email to:
   > harryproa-unsubscribe@...
   >
   >
   >
   > Your use of Yahoo! Groups is subject to
   http://au.docs.yahoo.com/info/terms/
   >
   >
   >


   To unsubscribe from this group, send an email to:
   harryproa-unsubscribe@...



   Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


[Non-text portions of this message have been removed]

G'day,

No idea if the price is correct or not, but it has been sitting there for 6
months, nobody looks like sailing it this year, so maybe.  Give Brett a
call, I am sure that between $200,000 and $1,000, you will find some common
ground!  The guy who engineered their masts is also doing ours.  Spitfire's
had to see some pretty huge loads as the boat on foils is very wide, and
there is allowance for (500 kgs, I think) water ballast.  There is very
little bury, which would not have helped.  A comparison would be nice, but
there are too many variables between this boat and others for it to be
meaningful.  A class cats, which can have either all go for wing masts,
which may be significant, although Moths (where weight aloft is more of an
issue) all go for sleeves.  All the high performance skiffs go for track and
bolt rope, so maybe none of it makes much difference?

Regards,

Rob
----- Original Message -----
From: "Robert" <cateran1949@...>
To: <harryproa@...>
Sent: Thursday, December 11, 2003 11:25 AM
Subject: [harryproa] Re: Sail Rig Options


> --- In harryproa@..., "Rob Denney" <proa@t...> wrote:
> >  Rumour is he got bored (maybe just scared!), tried to
> > sell it, couldn't and gave it back to the builders.  It is now
> sitting in
> > the yacht club yard alongside some of my old hulls.  Best offer
> over a grand
> > would probably buy it.
>
> Is that for real.
>
> >
> > Brett Burville the builder has had a lot of experience with
> hydrofoils as
> > the first person to get a moth (11' long, 1' wide overcanvassed
> dinghy)
> > flying.  He also had a smaller version of the Spitfire rig.  Also
> with a
> > round mast. When I have chatted with him he has always been
> completely open,
> > a really nice bloke.  If anyone has any questions, I am sure he
> wouild
> > answer them.  The Spitfire masts are about 300mm in diameter, 12m
> long with
> > a very steep taper.  I cannot lift the heavy end.  As far as I
> know, they
> > never played with a fine entry on the mast.  The sail was hoisted
> in two
> > bolt rope tracks, one on each side of the mast.
>
>
>
> I miss read the site and was looking at a crosssection of the
> crossbeam, not the mast.The twin bolt arrangement apears to be
> similar to the Dynarig.  I would certainly be interested in how much
> better it performs over a 10% wing mast and whether it is worth the
> hassles.
> Do the masts realy have to be that heavy? and there doesn't seem to
> be much depth of hull to hold them up.
> In heavy chop the boat would be comfortable but I wonder about doing
> 30-40 knots in ocean swell. I think that would scare me.
>  Robert
>
>
>
>
>
>
>
>
> >
> > Regards,
> >
> > Rob
> > ----- Original Message -----
> > From: "Robert" <cateran1949@y...>
> > To: <harryproa@...>
> > Sent: Wednesday, December 10, 2003 12:22 PM
> > Subject: [harryproa] Re: Sail Rig Options
> >
> >
> > > I've had a close lok at the site. The boat certainly goes well
> but if
> > > you look closely at the picture of the ww side of the sail, it
> > > doesn't look very smooth. You can see clearly wrinkles around the
> > > compression strut vanging the boom. In the section of the mast
> they
> > > show a fairly fine entry mast but in the talk on the overall rig
> they
> > > talk about a circular section mast.
> > > Don't really understand what they are doing. Possibly they are
> > > avoiding giving away too much detail, or the fine entry mast
> section
> > > didn't work.
> > > Robert
> > >
> > >
> > > --- In harryproa@..., "jjtctaylor"
> <jtaylor412@c...>
> > > wrote:
> > > > For those in Australia,  and lucky ones in Perth a possible
> > > > source for Wing masts using the Dynarig approach is BDG
> > > > Marine.   See link:      http://marine.bdg.com.au/contact.html
> > > >
> > > > They have been using it on their "spitfire" twin wingmast boat.
> > > > They have some arrangement with Windrush for a high speed
> > > > foil borne cat that also uses this technique.  Somebody has a
> > > > provisional patent, but not sure who it is.
> > > >
> > > > It's a place to start if you have interest in trying it.
> > > >
> > > > JT
> > > >
> > > >
> > > > --- In harryproa@..., "Robert"
> > > > <cateran1949@y...> wrote:
> > > > > --- In harryproa@..., "jjtctaylor"
> > > > <jtaylor412@c...>
> > > > > wrote:
> > > > > > The Dynawing  introducers, called powerfoils are only
> > > > intended
> > > > > > on their fixed wing dynafoils for sailboard use.  They are a
> > > > fixed
> > > > > > part of the wing sail.   They are not practical for hauling
> up
> > > 40-
> > > > > 50
> > > > > > feet on a mast.  They encapsulate the mast itself, so
> binding
> > > > is a
> > > > > > problem.
> > > > >
> > > > > Could this be overcome with slightly more clearance and
> > > > graphite
> > > > > lubrication? They already go to 6 or 7m. They don't have to
> > > > > encapsulate the mast, they can sit forward of it with the
> baton
> > > > > receivers projecting just past halfway of the mast. I can't
> see
> > > > any
> > > > > insurmountable problems, though a lot of cost in getting it
> > > > right.
> > > > > Maybe we should ask the powerfoil people.
> > > > >
> > > > >
> > > > >
> > > > >  They did not employ them with their dynarig effort,
> > > > > > hence they have no introducer.  A major flaw in their
> > > > execution.
> > > > >
> > > > > Agreed, it hardly seemed worth the hassle of having a double
> > > > luffed
> > > > > sail without the introducer.
> > > > >
> > > > > >
> > > > > > Seen them stick a a piece of foam for a parabolic reshaping
> > > > of
> > > > > > the mast leading edge.  That is not effective either cause
> it
> > > > > > negates a great portion of the lift  where the introducer is
> > > > head
> > > > > > into the wind and parts the airstream.  That lift is
> > > essentially
> > > > > lost
> > > > > > on the leading edge of your mast without a proper
> introducer.
> > > > > > The turbulent boundary layer caused by this poorly designed
> > > > > > nose has to reattach itself some distance down the wing.
> > > > > > Doesn't mean there isn't some lift, but the turbulent air is
> > > > mixing
> > > > > > with air at ambient pressure negating big lift opportunity.
> > > > >
> > > > > This is why I was wondering about having a mast with an
> > > > introducer
> > > > > built in to its shape, and having the mast rotate separately
> from
> > > > the
> > > > > boom. I am thinking of building a wing mast for my Jarcat and
> it
> > > > > might be worth trying but I am not sure about who to ask for
> > > > making
> > > > > suitable sails.
> > > > >
> > > > > >
> > > > > > Simple execution does not mean effective.  Reasons for few
> > > > > > commercial attempts with soft wing sails.
> > > > > >
> > > > > > JT
> > > > > >
> > > > > > --- In harryproa@..., "Robert"
> > > > > > <cateran1949@y...> wrote:
> > > > > > > Elegant simplicity. Does it have a line to the top gaff to
> > > > > control
> > > > > > > twist? Would the top gaff act to some extent as an end
> > > > plate?
> > > > > > Much as
> > > > > > > I like the simplicity, I can't help wanting to fiddle
> with it
> > > to
> > > > > make
> > > > > > > it go that little bit better.
> > > > > > > How would one of these go with a rotating wing mast to
> > > > give
> > > > > > finer
> > > > > > > entry and control camber? It would probably require
> split  or
> > > > > > twinned
> > > > > > > battens though, and outhaul tension controls to do it
> > > > properly.
> > > > > It
> > > > > > > might be better to go the whole hog and use dynawing foil
> > > > > > inducers
> > > > > > > and their related battens. Or go even further and replace
> > > > the
> > > > > > top
> > > > > > > gaff with a batten, enclose the area between the top gaff
> > > > and
> > > > > > the
> > > > > > > mast and you have a dynawing.
> > > > > > > A problem with all these rigs is how to attach stays to
> their
> > > > > > optimum
> > > > > > > position of ~2/3 of the way up the mast and still allow
> > > > reefing.
> > > > > > This
> > > > > > > can be overcome with a litle extra weight in stiffening
> and
> > > > > > attach
> > > > > > > them higher to the mast or even to the sail.
> > > > > > >  I would like to see some boat to boat comparisons of the
> > > > > > various
> > > > > > > rigs on Harryproas, but first we have to get some boats
> > > > sailing.
> > > > > > > Robert
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > --- In harryproa@..., "proaconstrictor"
> > > > > > > <proaconstrictor@y...> wrote:
> > > > > > > > --- In harryproa@..., "Robert"
> > > > > > <cateran1949@y...>
> > > > > > > > wrote:
> > > > > > > > > Personally I like the idea of a soft wing sail, in
> fact I
> > > > > quite
> > > > > > > > like
> > > > > > > > > Wharram's high gaff soft wing
> > > > > > > >
> > > > > > > >
> > > > > > > > Did you catch this?
> > > > > > > >
> > > > > > > > http://www.themultihull.com/woods/ps1.htm
> > >
> > >
> > > To unsubscribe from this group, send an email to:
> > > harryproa-unsubscribe@...
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> > http://au.docs.yahoo.com/info/terms/
> > >
> > >
> > >
>
>
> To unsubscribe from this group, send an email to:
> harryproa-unsubscribe@...
>
>
>
> Your use of Yahoo! Groups is subject to
http://au.docs.yahoo.com/info/terms/
>
>
>

--- In harryproa@..., "Rob Denney" <proa@t...> wrote:
>  Rumour is he got bored (maybe just scared!), tried to
> sell it, couldn't and gave it back to the builders.  It is now
sitting in
> the yacht club yard alongside some of my old hulls.  Best offer
over a grand
> would probably buy it.

Is that for real.

>
> Brett Burville the builder has had a lot of experience with
hydrofoils as
> the first person to get a moth (11' long, 1' wide overcanvassed
dinghy)
> flying.  He also had a smaller version of the Spitfire rig.  Also
with a
> round mast. When I have chatted with him he has always been
completely open,
> a really nice bloke.  If anyone has any questions, I am sure he
wouild
> answer them.  The Spitfire masts are about 300mm in diameter, 12m
long with
> a very steep taper.  I cannot lift the heavy end.  As far as I
know, they
> never played with a fine entry on the mast.  The sail was hoisted
in two
> bolt rope tracks, one on each side of the mast.



I miss read the site and was looking at a crosssection of the
crossbeam, not the mast.The twin bolt arrangement apears to be
similar to the Dynarig.  I would certainly be interested in how much
better it performs over a 10% wing mast and whether it is worth the
hassles.
Do the masts realy have to be that heavy? and there doesn't seem to
be much depth of hull to hold them up.
In heavy chop the boat would be comfortable but I wonder about doing
30-40 knots in ocean swell. I think that would scare me.
  Robert








>
> Regards,
>
> Rob
> ----- Original Message -----
> From: "Robert" <cateran1949@y...>
> To: <harryproa@...>
> Sent: Wednesday, December 10, 2003 12:22 PM
> Subject: [harryproa] Re: Sail Rig Options
>
>
> > I've had a close lok at the site. The boat certainly goes well
but if
> > you look closely at the picture of the ww side of the sail, it
> > doesn't look very smooth. You can see clearly wrinkles around the
> > compression strut vanging the boom. In the section of the mast
they
> > show a fairly fine entry mast but in the talk on the overall rig
they
> > talk about a circular section mast.
> > Don't really understand what they are doing. Possibly they are
> > avoiding giving away too much detail, or the fine entry mast
section
> > didn't work.
> > Robert
> >
> >
> > --- In harryproa@..., "jjtctaylor"
<jtaylor412@c...>
> > wrote:
> > > For those in Australia,  and lucky ones in Perth a possible
> > > source for Wing masts using the Dynarig approach is BDG
> > > Marine.   See link:      http://marine.bdg.com.au/contact.html
> > >
> > > They have been using it on their "spitfire" twin wingmast boat.
> > > They have some arrangement with Windrush for a high speed
> > > foil borne cat that also uses this technique.  Somebody has a
> > > provisional patent, but not sure who it is.
> > >
> > > It's a place to start if you have interest in trying it.
> > >
> > > JT
> > >
> > >
> > > --- In harryproa@..., "Robert"
> > > <cateran1949@y...> wrote:
> > > > --- In harryproa@..., "jjtctaylor"
> > > <jtaylor412@c...>
> > > > wrote:
> > > > > The Dynawing  introducers, called powerfoils are only
> > > intended
> > > > > on their fixed wing dynafoils for sailboard use.  They are a
> > > fixed
> > > > > part of the wing sail.   They are not practical for hauling
up
> > 40-
> > > > 50
> > > > > feet on a mast.  They encapsulate the mast itself, so
binding
> > > is a
> > > > > problem.
> > > >
> > > > Could this be overcome with slightly more clearance and
> > > graphite
> > > > lubrication? They already go to 6 or 7m. They don't have to
> > > > encapsulate the mast, they can sit forward of it with the
baton
> > > > receivers projecting just past halfway of the mast. I can't
see
> > > any
> > > > insurmountable problems, though a lot of cost in getting it
> > > right.
> > > > Maybe we should ask the powerfoil people.
> > > >
> > > >
> > > >
> > > >  They did not employ them with their dynarig effort,
> > > > > hence they have no introducer.  A major flaw in their
> > > execution.
> > > >
> > > > Agreed, it hardly seemed worth the hassle of having a double
> > > luffed
> > > > sail without the introducer.
> > > >
> > > > >
> > > > > Seen them stick a a piece of foam for a parabolic reshaping
> > > of
> > > > > the mast leading edge.  That is not effective either cause
it
> > > > > negates a great portion of the lift  where the introducer is
> > > head
> > > > > into the wind and parts the airstream.  That lift is
> > essentially
> > > > lost
> > > > > on the leading edge of your mast without a proper
introducer.
> > > > > The turbulent boundary layer caused by this poorly designed
> > > > > nose has to reattach itself some distance down the wing.
> > > > > Doesn't mean there isn't some lift, but the turbulent air is
> > > mixing
> > > > > with air at ambient pressure negating big lift opportunity.
> > > >
> > > > This is why I was wondering about having a mast with an
> > > introducer
> > > > built in to its shape, and having the mast rotate separately
from
> > > the
> > > > boom. I am thinking of building a wing mast for my Jarcat and
it
> > > > might be worth trying but I am not sure about who to ask for
> > > making
> > > > suitable sails.
> > > >
> > > > >
> > > > > Simple execution does not mean effective.  Reasons for few
> > > > > commercial attempts with soft wing sails.
> > > > >
> > > > > JT
> > > > >
> > > > > --- In harryproa@..., "Robert"
> > > > > <cateran1949@y...> wrote:
> > > > > > Elegant simplicity. Does it have a line to the top gaff to
> > > > control
> > > > > > twist? Would the top gaff act to some extent as an end
> > > plate?
> > > > > Much as
> > > > > > I like the simplicity, I can't help wanting to fiddle
with it
> > to
> > > > make
> > > > > > it go that little bit better.
> > > > > > How would one of these go with a rotating wing mast to
> > > give
> > > > > finer
> > > > > > entry and control camber? It would probably require
split  or
> > > > > twinned
> > > > > > battens though, and outhaul tension controls to do it
> > > properly.
> > > > It
> > > > > > might be better to go the whole hog and use dynawing foil
> > > > > inducers
> > > > > > and their related battens. Or go even further and replace
> > > the
> > > > > top
> > > > > > gaff with a batten, enclose the area between the top gaff
> > > and
> > > > > the
> > > > > > mast and you have a dynawing.
> > > > > > A problem with all these rigs is how to attach stays to
their
> > > > > optimum
> > > > > > position of ~2/3 of the way up the mast and still allow
> > > reefing.
> > > > > This
> > > > > > can be overcome with a litle extra weight in stiffening
and
> > > > > attach
> > > > > > them higher to the mast or even to the sail.
> > > > > >  I would like to see some boat to boat comparisons of the
> > > > > various
> > > > > > rigs on Harryproas, but first we have to get some boats
> > > sailing.
> > > > > > Robert
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > --- In harryproa@..., "proaconstrictor"
> > > > > > <proaconstrictor@y...> wrote:
> > > > > > > --- In harryproa@..., "Robert"
> > > > > <cateran1949@y...>
> > > > > > > wrote:
> > > > > > > > Personally I like the idea of a soft wing sail, in
fact I
> > > > quite
> > > > > > > like
> > > > > > > > Wharram's high gaff soft wing
> > > > > > >
> > > > > > >
> > > > > > > Did you catch this?
> > > > > > >
> > > > > > > http://www.themultihull.com/woods/ps1.htm
> >
> >
> > To unsubscribe from this group, send an email to:
> > harryproa-unsubscribe@...
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://au.docs.yahoo.com/info/terms/
> >
> >
> >

--- In harryproa@..., "Rob Denney" <proa@t...> wrote:
> G'day,
>
> Spitfire was built, no expense spared and sailed maybe 5 times.
Depending
> who you spoke to, it got to 30 knots in not much breeze, tacked on
it's
> foils and was the next big thing.  Problems with steering and the
rig
> (probably the ones you mention) were apparently sorted before it
was sent to
> it's owner in Sydney.  Rumour is he got bored (maybe just scared!),


I can understand that. It would be nice and comfortable in a chop but
the thought of 30-40knots in ocean swells.....




  tried to
> sell it, couldn't and gave it back to the builders.  It is now
sitting in
> the yacht club yard alongside some of my old hulls.  Best offer
over a grand
> would probably buy it.


Is that for real?






>
> Brett Burville the builder has had a lot of experience with
hydrofoils as
> the first person to get a moth (11' long, 1' wide overcanvassed
dinghy)
> flying.  He also had a smaller version of the Spitfire rig.  Also
with a
> round mast. When I have chatted with him he has always been
completely open,
> a really nice bloke.  If anyone has any questions, I am sure he
wouild
> answer them.  The Spitfire masts are about 300mm in diameter, 12m
long with
> a very steep taper.  I cannot lift the heavy end.  As far as I
know, they
> never played with a fine entry on the mast.


I misread the website without my glasses and was looking at the beam
cross section rather than the mast.




  The sail was hoisted in two
> bolt rope tracks, one on each side of the mast.

It sound a bit like the Dynarig. It would be interesting to know how
it compares to a 10% wingmast in lift to drag ratio and whether it is
worth the hassle.


Robert



>
> Regards,
>
> Rob
> ----- Original Message -----
> From: "Robert" <cateran1949@y...>
> To: <harryproa@...>
> Sent: Wednesday, December 10, 2003 12:22 PM
> Subject: [harryproa] Re: Sail Rig Options
>
>
> > I've had a close lok at the site. The boat certainly goes well
but if
> > you look closely at the picture of the ww side of the sail, it
> > doesn't look very smooth. You can see clearly wrinkles around the
> > compression strut vanging the boom. In the section of the mast
they
> > show a fairly fine entry mast but in the talk on the overall rig
they
> > talk about a circular section mast.
> > Don't really understand what they are doing. Possibly they are
> > avoiding giving away too much detail, or the fine entry mast
section
> > didn't work.
> > Robert
> >
> >
> > --- In harryproa@..., "jjtctaylor"
<jtaylor412@c...>
> > wrote:
> > > For those in Australia,  and lucky ones in Perth a possible
> > > source for Wing masts using the Dynarig approach is BDG
> > > Marine.   See link:      http://marine.bdg.com.au/contact.html
> > >
> > > They have been using it on their "spitfire" twin wingmast boat.
> > > They have some arrangement with Windrush for a high speed
> > > foil borne cat that also uses this technique.  Somebody has a
> > > provisional patent, but not sure who it is.
> > >
> > > It's a place to start if you have interest in trying it.
> > >
> > > JT
> > >
> > >
> > > --- In harryproa@..., "Robert"
> > > <cateran1949@y...> wrote:
> > > > --- In harryproa@..., "jjtctaylor"
> > > <jtaylor412@c...>
> > > > wrote:
> > > > > The Dynawing  introducers, called powerfoils are only
> > > intended
> > > > > on their fixed wing dynafoils for sailboard use.  They are a
> > > fixed
> > > > > part of the wing sail.   They are not practical for hauling
up
> > 40-
> > > > 50
> > > > > feet on a mast.  They encapsulate the mast itself, so
binding
> > > is a
> > > > > problem.
> > > >
> > > > Could this be overcome with slightly more clearance and
> > > graphite
> > > > lubrication? They already go to 6 or 7m. They don't have to
> > > > encapsulate the mast, they can sit forward of it with the
baton
> > > > receivers projecting just past halfway of the mast. I can't
see
> > > any
> > > > insurmountable problems, though a lot of cost in getting it
> > > right.
> > > > Maybe we should ask the powerfoil people.
> > > >
> > > >
> > > >
> > > >  They did not employ them with their dynarig effort,
> > > > > hence they have no introducer.  A major flaw in their
> > > execution.
> > > >
> > > > Agreed, it hardly seemed worth the hassle of having a double
> > > luffed
> > > > sail without the introducer.
> > > >
> > > > >
> > > > > Seen them stick a a piece of foam for a parabolic reshaping
> > > of
> > > > > the mast leading edge.  That is not effective either cause
it
> > > > > negates a great portion of the lift  where the introducer is
> > > head
> > > > > into the wind and parts the airstream.  That lift is
> > essentially
> > > > lost
> > > > > on the leading edge of your mast without a proper
introducer.
> > > > > The turbulent boundary layer caused by this poorly designed
> > > > > nose has to reattach itself some distance down the wing.
> > > > > Doesn't mean there isn't some lift, but the turbulent air is
> > > mixing
> > > > > with air at ambient pressure negating big lift opportunity.
> > > >
> > > > This is why I was wondering about having a mast with an
> > > introducer
> > > > built in to its shape, and having the mast rotate separately
from
> > > the
> > > > boom. I am thinking of building a wing mast for my Jarcat and
it
> > > > might be worth trying but I am not sure about who to ask for
> > > making
> > > > suitable sails.
> > > >
> > > > >
> > > > > Simple execution does not mean effective.  Reasons for few
> > > > > commercial attempts with soft wing sails.
> > > > >
> > > > > JT
> > > > >
> > > > > --- In harryproa@..., "Robert"
> > > > > <cateran1949@y...> wrote:
> > > > > > Elegant simplicity. Does it have a line to the top gaff to
> > > > control
> > > > > > twist? Would the top gaff act to some extent as an end
> > > plate?
> > > > > Much as
> > > > > > I like the simplicity, I can't help wanting to fiddle
with it
> > to
> > > > make
> > > > > > it go that little bit better.
> > > > > > How would one of these go with a rotating wing mast to
> > > give
> > > > > finer
> > > > > > entry and control camber? It would probably require
split  or
> > > > > twinned
> > > > > > battens though, and outhaul tension controls to do it
> > > properly.
> > > > It
> > > > > > might be better to go the whole hog and use dynawing foil
> > > > > inducers
> > > > > > and their related battens. Or go even further and replace
> > > the
> > > > > top
> > > > > > gaff with a batten, enclose the area between the top gaff
> > > and
> > > > > the
> > > > > > mast and you have a dynawing.
> > > > > > A problem with all these rigs is how to attach stays to
their
> > > > > optimum
> > > > > > position of ~2/3 of the way up the mast and still allow
> > > reefing.
> > > > > This
> > > > > > can be overcome with a litle extra weight in stiffening
and
> > > > > attach
> > > > > > them higher to the mast or even to the sail.
> > > > > >  I would like to see some boat to boat comparisons of the
> > > > > various
> > > > > > rigs on Harryproas, but first we have to get some boats
> > > sailing.
> > > > > > Robert
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > --- In harryproa@..., "proaconstrictor"
> > > > > > <proaconstrictor@y...> wrote:
> > > > > > > --- In harryproa@..., "Robert"
> > > > > <cateran1949@y...>
> > > > > > > wrote:
> > > > > > > > Personally I like the idea of a soft wing sail, in
fact I
> > > > quite
> > > > > > > like
> > > > > > > > Wharram's high gaff soft wing
> > > > > > >
> > > > > > >
> > > > > > > Did you catch this?
> > > > > > >
> > > > > > > http://www.themultihull.com/woods/ps1.htm
> >
> >
> > To unsubscribe from this group, send an email to:
> > harryproa-unsubscribe@...
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://au.docs.yahoo.com/info/terms/
> >
> >
> >

G'day,

Spitfire was built, no expense spared and sailed maybe 5 times.  Depending
who you spoke to, it got to 30 knots in not much breeze, tacked on it's
foils and was the next big thing.  Problems with steering and the rig
(probably the ones you mention) were apparently sorted before it was sent to
it's owner in Sydney.  Rumour is he got bored (maybe just scared!), tried to
sell it, couldn't and gave it back to the builders.  It is now sitting in
the yacht club yard alongside some of my old hulls.  Best offer over a grand
would probably buy it.

Brett Burville the builder has had a lot of experience with hydrofoils as
the first person to get a moth (11' long, 1' wide overcanvassed dinghy)
flying.  He also had a smaller version of the Spitfire rig.  Also with a
round mast. When I have chatted with him he has always been completely open,
a really nice bloke.  If anyone has any questions, I am sure he wouild
answer them.  The Spitfire masts are about 300mm in diameter, 12m long with
a very steep taper.  I cannot lift the heavy end.  As far as I know, they
never played with a fine entry on the mast.  The sail was hoisted in two
bolt rope tracks, one on each side of the mast.

Regards,

Rob
----- Original Message -----
From: "Robert" <cateran1949@...>
To: <harryproa@...>
Sent: Wednesday, December 10, 2003 12:22 PM
Subject: [harryproa] Re: Sail Rig Options


> I've had a close lok at the site. The boat certainly goes well but if
> you look closely at the picture of the ww side of the sail, it
> doesn't look very smooth. You can see clearly wrinkles around the
> compression strut vanging the boom. In the section of the mast they
> show a fairly fine entry mast but in the talk on the overall rig they
> talk about a circular section mast.
> Don't really understand what they are doing. Possibly they are
> avoiding giving away too much detail, or the fine entry mast section
> didn't work.
> Robert
>
>
> --- In harryproa@..., "jjtctaylor" <jtaylor412@c...>
> wrote:
> > For those in Australia,  and lucky ones in Perth a possible
> > source for Wing masts using the Dynarig approach is BDG
> > Marine.   See link:      http://marine.bdg.com.au/contact.html
> >
> > They have been using it on their "spitfire" twin wingmast boat.
> > They have some arrangement with Windrush for a high speed
> > foil borne cat that also uses this technique.  Somebody has a
> > provisional patent, but not sure who it is.
> >
> > It's a place to start if you have interest in trying it.
> >
> > JT
> >
> >
> > --- In harryproa@..., "Robert"
> > <cateran1949@y...> wrote:
> > > --- In harryproa@..., "jjtctaylor"
> > <jtaylor412@c...>
> > > wrote:
> > > > The Dynawing  introducers, called powerfoils are only
> > intended
> > > > on their fixed wing dynafoils for sailboard use.  They are a
> > fixed
> > > > part of the wing sail.   They are not practical for hauling up
> 40-
> > > 50
> > > > feet on a mast.  They encapsulate the mast itself, so binding
> > is a
> > > > problem.
> > >
> > > Could this be overcome with slightly more clearance and
> > graphite
> > > lubrication? They already go to 6 or 7m. They don't have to
> > > encapsulate the mast, they can sit forward of it with the baton
> > > receivers projecting just past halfway of the mast. I can't see
> > any
> > > insurmountable problems, though a lot of cost in getting it
> > right.
> > > Maybe we should ask the powerfoil people.
> > >
> > >
> > >
> > >  They did not employ them with their dynarig effort,
> > > > hence they have no introducer.  A major flaw in their
> > execution.
> > >
> > > Agreed, it hardly seemed worth the hassle of having a double
> > luffed
> > > sail without the introducer.
> > >
> > > >
> > > > Seen them stick a a piece of foam for a parabolic reshaping
> > of
> > > > the mast leading edge.  That is not effective either cause it
> > > > negates a great portion of the lift  where the introducer is
> > head
> > > > into the wind and parts the airstream.  That lift is
> essentially
> > > lost
> > > > on the leading edge of your mast without a proper introducer.
> > > > The turbulent boundary layer caused by this poorly designed
> > > > nose has to reattach itself some distance down the wing.
> > > > Doesn't mean there isn't some lift, but the turbulent air is
> > mixing
> > > > with air at ambient pressure negating big lift opportunity.
> > >
> > > This is why I was wondering about having a mast with an
> > introducer
> > > built in to its shape, and having the mast rotate separately from
> > the
> > > boom. I am thinking of building a wing mast for my Jarcat and it
> > > might be worth trying but I am not sure about who to ask for
> > making
> > > suitable sails.
> > >
> > > >
> > > > Simple execution does not mean effective.  Reasons for few
> > > > commercial attempts with soft wing sails.
> > > >
> > > > JT
> > > >
> > > > --- In harryproa@..., "Robert"
> > > > <cateran1949@y...> wrote:
> > > > > Elegant simplicity. Does it have a line to the top gaff to
> > > control
> > > > > twist? Would the top gaff act to some extent as an end
> > plate?
> > > > Much as
> > > > > I like the simplicity, I can't help wanting to fiddle with it
> to
> > > make
> > > > > it go that little bit better.
> > > > > How would one of these go with a rotating wing mast to
> > give
> > > > finer
> > > > > entry and control camber? It would probably require split  or
> > > > twinned
> > > > > battens though, and outhaul tension controls to do it
> > properly.
> > > It
> > > > > might be better to go the whole hog and use dynawing foil
> > > > inducers
> > > > > and their related battens. Or go even further and replace
> > the
> > > > top
> > > > > gaff with a batten, enclose the area between the top gaff
> > and
> > > > the
> > > > > mast and you have a dynawing.
> > > > > A problem with all these rigs is how to attach stays to their
> > > > optimum
> > > > > position of ~2/3 of the way up the mast and still allow
> > reefing.
> > > > This
> > > > > can be overcome with a litle extra weight in stiffening and
> > > > attach
> > > > > them higher to the mast or even to the sail.
> > > > >  I would like to see some boat to boat comparisons of the
> > > > various
> > > > > rigs on Harryproas, but first we have to get some boats
> > sailing.
> > > > > Robert
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > --- In harryproa@..., "proaconstrictor"
> > > > > <proaconstrictor@y...> wrote:
> > > > > > --- In harryproa@..., "Robert"
> > > > <cateran1949@y...>
> > > > > > wrote:
> > > > > > > Personally I like the idea of a soft wing sail, in fact I
> > > quite
> > > > > > like
> > > > > > > Wharram's high gaff soft wing
> > > > > >
> > > > > >
> > > > > > Did you catch this?
> > > > > >
> > > > > > http://www.themultihull.com/woods/ps1.htm
>
>
> To unsubscribe from this group, send an email to:
> harryproa-unsubscribe@...
>
>
>
> Your use of Yahoo! Groups is subject to
http://au.docs.yahoo.com/info/terms/
>
>
>

I've had a close lok at the site. The boat certainly goes well but if
you look closely at the picture of the ww side of the sail, it
doesn't look very smooth. You can see clearly wrinkles around the
compression strut vanging the boom. In the section of the mast they
show a fairly fine entry mast but in the talk on the overall rig they
talk about a circular section mast.
Don't really understand what they are doing. Possibly they are
avoiding giving away too much detail, or the fine entry mast section
didn't work.
Robert


--- In harryproa@..., "jjtctaylor" <jtaylor412@c...>
wrote:
> For those in Australia,  and lucky ones in Perth a possible
> source for Wing masts using the Dynarig approach is BDG
> Marine.   See link:      http://marine.bdg.com.au/contact.html
>
> They have been using it on their "spitfire" twin wingmast boat.
> They have some arrangement with Windrush for a high speed
> foil borne cat that also uses this technique.  Somebody has a
> provisional patent, but not sure who it is.
>
> It's a place to start if you have interest in trying it.
>
> JT
>
>
> --- In harryproa@..., "Robert"
> <cateran1949@y...> wrote:
> > --- In harryproa@..., "jjtctaylor"
> <jtaylor412@c...>
> > wrote:
> > > The Dynawing  introducers, called powerfoils are only
> intended
> > > on their fixed wing dynafoils for sailboard use.  They are a
> fixed
> > > part of the wing sail.   They are not practical for hauling up
40-
> > 50
> > > feet on a mast.  They encapsulate the mast itself, so binding
> is a
> > > problem.
> >
> > Could this be overcome with slightly more clearance and
> graphite
> > lubrication? They already go to 6 or 7m. They don't have to
> > encapsulate the mast, they can sit forward of it with the baton
> > receivers projecting just past halfway of the mast. I can't see
> any
> > insurmountable problems, though a lot of cost in getting it
> right.
> > Maybe we should ask the powerfoil people.
> >
> >
> >
> >  They did not employ them with their dynarig effort,
> > > hence they have no introducer.  A major flaw in their
> execution.
> >
> > Agreed, it hardly seemed worth the hassle of having a double
> luffed
> > sail without the introducer.
> >
> > >
> > > Seen them stick a a piece of foam for a parabolic reshaping
> of
> > > the mast leading edge.  That is not effective either cause it
> > > negates a great portion of the lift  where the introducer is
> head
> > > into the wind and parts the airstream.  That lift is
essentially
> > lost
> > > on the leading edge of your mast without a proper introducer.
> > > The turbulent boundary layer caused by this poorly designed
> > > nose has to reattach itself some distance down the wing.
> > > Doesn't mean there isn't some lift, but the turbulent air is
> mixing
> > > with air at ambient pressure negating big lift opportunity.
> >
> > This is why I was wondering about having a mast with an
> introducer
> > built in to its shape, and having the mast rotate separately from
> the
> > boom. I am thinking of building a wing mast for my Jarcat and it
> > might be worth trying but I am not sure about who to ask for
> making
> > suitable sails.
> >
> > >
> > > Simple execution does not mean effective.  Reasons for few
> > > commercial attempts with soft wing sails.
> > >
> > > JT
> > >
> > > --- In harryproa@..., "Robert"
> > > <cateran1949@y...> wrote:
> > > > Elegant simplicity. Does it have a line to the top gaff to
> > control
> > > > twist? Would the top gaff act to some extent as an end
> plate?
> > > Much as
> > > > I like the simplicity, I can't help wanting to fiddle with it
to
> > make
> > > > it go that little bit better.
> > > > How would one of these go with a rotating wing mast to
> give
> > > finer
> > > > entry and control camber? It would probably require split  or
> > > twinned
> > > > battens though, and outhaul tension controls to do it
> properly.
> > It
> > > > might be better to go the whole hog and use dynawing foil
> > > inducers
> > > > and their related battens. Or go even further and replace
> the
> > > top
> > > > gaff with a batten, enclose the area between the top gaff
> and
> > > the
> > > > mast and you have a dynawing.
> > > > A problem with all these rigs is how to attach stays to their
> > > optimum
> > > > position of ~2/3 of the way up the mast and still allow
> reefing.
> > > This
> > > > can be overcome with a litle extra weight in stiffening and
> > > attach
> > > > them higher to the mast or even to the sail.
> > > >  I would like to see some boat to boat comparisons of the
> > > various
> > > > rigs on Harryproas, but first we have to get some boats
> sailing.
> > > > Robert
> > > >
> > > >
> > > >
> > > >
> > > > --- In harryproa@..., "proaconstrictor"
> > > > <proaconstrictor@y...> wrote:
> > > > > --- In harryproa@..., "Robert"
> > > <cateran1949@y...>
> > > > > wrote:
> > > > > > Personally I like the idea of a soft wing sail, in fact I
> > quite
> > > > > like
> > > > > > Wharram's high gaff soft wing
> > > > >
> > > > >
> > > > > Did you catch this?
> > > > >
> > > > > http://www.themultihull.com/woods/ps1.htm

For those in Australia,  and lucky ones in Perth a possible
source for Wing masts using the Dynarig approach is BDG
Marine.   See link:      http://marine.bdg.com.au/contact.html

They have been using it on their "spitfire" twin wingmast boat.
They have some arrangement with Windrush for a high speed
foil borne cat that also uses this technique.  Somebody has a
provisional patent, but not sure who it is.

It's a place to start if you have interest in trying it.

JT


--- In harryproa@..., "Robert"
<cateran1949@y...> wrote:
> --- In harryproa@..., "jjtctaylor"
<jtaylor412@c...>
> wrote:
> > The Dynawing  introducers, called powerfoils are only
intended
> > on their fixed wing dynafoils for sailboard use.  They are a
fixed
> > part of the wing sail.   They are not practical for hauling up 40-
> 50
> > feet on a mast.  They encapsulate the mast itself, so binding
is a
> > problem.
>
> Could this be overcome with slightly more clearance and
graphite
> lubrication? They already go to 6 or 7m. They don't have to
> encapsulate the mast, they can sit forward of it with the baton
> receivers projecting just past halfway of the mast. I can't see
any
> insurmountable problems, though a lot of cost in getting it
right.
> Maybe we should ask the powerfoil people.
>
>
>
>  They did not employ them with their dynarig effort,
> > hence they have no introducer.  A major flaw in their
execution.
>
> Agreed, it hardly seemed worth the hassle of having a double
luffed
> sail without the introducer.
>
> >
> > Seen them stick a a piece of foam for a parabolic reshaping
of
> > the mast leading edge.  That is not effective either cause it
> > negates a great portion of the lift  where the introducer is
head
> > into the wind and parts the airstream.  That lift is essentially
> lost
> > on the leading edge of your mast without a proper introducer.
> > The turbulent boundary layer caused by this poorly designed
> > nose has to reattach itself some distance down the wing.
> > Doesn't mean there isn't some lift, but the turbulent air is
mixing
> > with air at ambient pressure negating big lift opportunity.
>
> This is why I was wondering about having a mast with an
introducer
> built in to its shape, and having the mast rotate separately from
the
> boom. I am thinking of building a wing mast for my Jarcat and it
> might be worth trying but I am not sure about who to ask for
making
> suitable sails.
>
> >
> > Simple execution does not mean effective.  Reasons for few
> > commercial attempts with soft wing sails.
> >
> > JT
> >
> > --- In harryproa@..., "Robert"
> > <cateran1949@y...> wrote:
> > > Elegant simplicity. Does it have a line to the top gaff to
> control
> > > twist? Would the top gaff act to some extent as an end
plate?
> > Much as
> > > I like the simplicity, I can't help wanting to fiddle with it to
> make
> > > it go that little bit better.
> > > How would one of these go with a rotating wing mast to
give
> > finer
> > > entry and control camber? It would probably require split  or
> > twinned
> > > battens though, and outhaul tension controls to do it
properly.
> It
> > > might be better to go the whole hog and use dynawing foil
> > inducers
> > > and their related battens. Or go even further and replace
the
> > top
> > > gaff with a batten, enclose the area between the top gaff
and
> > the
> > > mast and you have a dynawing.
> > > A problem with all these rigs is how to attach stays to their
> > optimum
> > > position of ~2/3 of the way up the mast and still allow
reefing.
> > This
> > > can be overcome with a litle extra weight in stiffening and
> > attach
> > > them higher to the mast or even to the sail.
> > >  I would like to see some boat to boat comparisons of the
> > various
> > > rigs on Harryproas, but first we have to get some boats
sailing.
> > > Robert
> > >
> > >
> > >
> > >
> > > --- In harryproa@..., "proaconstrictor"
> > > <proaconstrictor@y...> wrote:
> > > > --- In harryproa@..., "Robert"
> > <cateran1949@y...>
> > > > wrote:
> > > > > Personally I like the idea of a soft wing sail, in fact I
> quite
> > > > like
> > > > > Wharram's high gaff soft wing
> > > >
> > > >
> > > > Did you catch this?
> > > >
> > > > http://www.themultihull.com/woods/ps1.htm

For those in Australia,  and lucky ones in Perth a possible
source for Wing masts using the Dynarig approach is BDG
Marine.   See link:      http://marine.bdg.com.au/contact.html

They have been using it on their "spitfire" twin wingmast boat.
They have some arrangement with Windrush for a high speed
foil borne cat that also uses this technique.  Somebody has a
provisional patent, but not sure who it is.

It's a place to start if you have interest in trying it.

JT


--- In harryproa@..., "Robert"
<cateran1949@y...> wrote:
> --- In harryproa@..., "jjtctaylor"
<jtaylor412@c...>
> wrote:
> > The Dynawing  introducers, called powerfoils are only
intended
> > on their fixed wing dynafoils for sailboard use.  They are a
fixed
> > part of the wing sail.   They are not practical for hauling up 40-
> 50
> > feet on a mast.  They encapsulate the mast itself, so binding
is a
> > problem.
>
> Could this be overcome with slightly more clearance and
graphite
> lubrication? They already go to 6 or 7m. They don't have to
> encapsulate the mast, they can sit forward of it with the baton
> receivers projecting just past halfway of the mast. I can't see
any
> insurmountable problems, though a lot of cost in getting it
right.
> Maybe we should ask the powerfoil people.
>
>
>
>  They did not employ them with their dynarig effort,
> > hence they have no introducer.  A major flaw in their
execution.
>
> Agreed, it hardly seemed worth the hassle of having a double
luffed
> sail without the introducer.
>
> >
> > Seen them stick a a piece of foam for a parabolic reshaping
of
> > the mast leading edge.  That is not effective either cause it
> > negates a great portion of the lift  where the introducer is
head
> > into the wind and parts the airstream.  That lift is essentially
> lost
> > on the leading edge of your mast without a proper introducer.
> > The turbulent boundary layer caused by this poorly designed
> > nose has to reattach itself some distance down the wing.
> > Doesn't mean there isn't some lift, but the turbulent air is
mixing
> > with air at ambient pressure negating big lift opportunity.
>
> This is why I was wondering about having a mast with an
introducer
> built in to its shape, and having the mast rotate separately from
the
> boom. I am thinking of building a wing mast for my Jarcat and it
> might be worth trying but I am not sure about who to ask for
making
> suitable sails.
>
> >
> > Simple execution does not mean effective.  Reasons for few
> > commercial attempts with soft wing sails.
> >
> > JT
> >
> > --- In harryproa@..., "Robert"
> > <cateran1949@y...> wrote:
> > > Elegant simplicity. Does it have a line to the top gaff to
> control
> > > twist? Would the top gaff act to some extent as an end
plate?
> > Much as
> > > I like the simplicity, I can't help wanting to fiddle with it to
> make
> > > it go that little bit better.
> > > How would one of these go with a rotating wing mast to
give
> > finer
> > > entry and control camber? It would probably require split  or
> > twinned
> > > battens though, and outhaul tension controls to do it
properly.
> It
> > > might be better to go the whole hog and use dynawing foil
> > inducers
> > > and their related battens. Or go even further and replace
the
> > top
> > > gaff with a batten, enclose the area between the top gaff
and
> > the
> > > mast and you have a dynawing.
> > > A problem with all these rigs is how to attach stays to their
> > optimum
> > > position of ~2/3 of the way up the mast and still allow
reefing.
> > This
> > > can be overcome with a litle extra weight in stiffening and
> > attach
> > > them higher to the mast or even to the sail.
> > >  I would like to see some boat to boat comparisons of the
> > various
> > > rigs on Harryproas, but first we have to get some boats
sailing.
> > > Robert
> > >
> > >
> > >
> > >
> > > --- In harryproa@..., "proaconstrictor"
> > > <proaconstrictor@y...> wrote:
> > > > --- In harryproa@..., "Robert"
> > <cateran1949@y...>
> > > > wrote:
> > > > > Personally I like the idea of a soft wing sail, in fact I
> quite
> > > > like
> > > > > Wharram's high gaff soft wing
> > > >
> > > >
> > > > Did you catch this?
> > > >
> > > > http://www.themultihull.com/woods/ps1.htm

G'day,

Just as it got interesting (ie I was having problems sorting out how it
would all work), I broke my achilles tendon, and got a sponsorship deal
which allowed me to employ someone to finish it while I recovered.  Rather
than have them mess it up, I decided to make it a one piece mast.  They
joined the two pieces and cut a taper in it.  Stuffed it up and had to do it
again, so the mast is heavy, and of relatively dubious quality.  Still keen
on the idea, but will be using it on beams next.  Main lesson was that the
easy way to do it is with the large diameter piece at the top.  No idea how
this will affect the set of the sail, but suspect not well.  Still on the to
do list, once I get an Elementarry to play with.

Regards,

Rob


----- Original Message -----
From: "Rolf Nilsen" <rolf@...>
To: <harryproa@...>
Sent: Monday, December 08, 2003 2:47 PM
Subject: Re: [harryproa] Re: Sail Rig Options


>
> Sounds like an opportunity for Rob to dust off his telescoping mast ?
> I dont think I have seen an report on how that project ended and what
> was learnt from it.
>
>
> Best regards
> Rolf Nilsen
>
>
>
> To unsubscribe from this group, send an email to:
> harryproa-unsubscribe@...
>
>
>
> Your use of Yahoo! Groups is subject to
http://au.docs.yahoo.com/info/terms/
>
>
>

--- In harryproa@..., "jjtctaylor" <jtaylor412@c...>
wrote:
> The Dynawing  introducers, called powerfoils are only intended
> on their fixed wing dynafoils for sailboard use.  They are a fixed
> part of the wing sail.   They are not practical for hauling up 40-
50
> feet on a mast.  They encapsulate the mast itself, so binding is a
> problem.

Could this be overcome with slightly more clearance and graphite
lubrication? They already go to 6 or 7m. They don't have to
encapsulate the mast, they can sit forward of it with the baton
receivers projecting just past halfway of the mast. I can't see any
insurmountable problems, though a lot of cost in getting it right.
Maybe we should ask the powerfoil people.



  They did not employ them with their dynarig effort,
> hence they have no introducer.  A major flaw in their execution.

Agreed, it hardly seemed worth the hassle of having a double luffed
sail without the introducer.

>
> Seen them stick a a piece of foam for a parabolic reshaping of
> the mast leading edge.  That is not effective either cause it
> negates a great portion of the lift  where the introducer is head
> into the wind and parts the airstream.  That lift is essentially
lost
> on the leading edge of your mast without a proper introducer.
> The turbulent boundary layer caused by this poorly designed
> nose has to reattach itself some distance down the wing.
> Doesn't mean there isn't some lift, but the turbulent air is mixing
> with air at ambient pressure negating big lift opportunity.

This is why I was wondering about having a mast with an introducer
built in to its shape, and having the mast rotate separately from the
boom. I am thinking of building a wing mast for my Jarcat and it
might be worth trying but I am not sure about who to ask for making
suitable sails.

>
> Simple execution does not mean effective.  Reasons for few
> commercial attempts with soft wing sails.
>
> JT
>
> --- In harryproa@..., "Robert"
> <cateran1949@y...> wrote:
> > Elegant simplicity. Does it have a line to the top gaff to
control
> > twist? Would the top gaff act to some extent as an end plate?
> Much as
> > I like the simplicity, I can't help wanting to fiddle with it to
make
> > it go that little bit better.
> > How would one of these go with a rotating wing mast to give
> finer
> > entry and control camber? It would probably require split  or
> twinned
> > battens though, and outhaul tension controls to do it properly.
It
> > might be better to go the whole hog and use dynawing foil
> inducers
> > and their related battens. Or go even further and replace the
> top
> > gaff with a batten, enclose the area between the top gaff and
> the
> > mast and you have a dynawing.
> > A problem with all these rigs is how to attach stays to their
> optimum
> > position of ~2/3 of the way up the mast and still allow reefing.
> This
> > can be overcome with a litle extra weight in stiffening and
> attach
> > them higher to the mast or even to the sail.
> >  I would like to see some boat to boat comparisons of the
> various
> > rigs on Harryproas, but first we have to get some boats sailing.
> > Robert
> >
> >
> >
> >
> > --- In harryproa@..., "proaconstrictor"
> > <proaconstrictor@y...> wrote:
> > > --- In harryproa@..., "Robert"
> <cateran1949@y...>
> > > wrote:
> > > > Personally I like the idea of a soft wing sail, in fact I
quite
> > > like
> > > > Wharram's high gaff soft wing
> > >
> > >
> > > Did you catch this?
> > >
> > > http://www.themultihull.com/woods/ps1.htm

The Dynawing  introducers, called powerfoils are only intended
on their fixed wing dynafoils for sailboard use.  They are a fixed
part of the wing sail.   They are not practical for hauling up 40-50
feet on a mast.  They encapsulate the mast itself, so binding is a
problem.  They did not employ them with their dynarig effort,
hence they have no introducer.  A major flaw in their execution.

Seen them stick a a piece of foam for a parabolic reshaping of
the mast leading edge.  That is not effective either cause it
negates a great portion of the lift  where the introducer is head
into the wind and parts the airstream.  That lift is essentially lost
on the leading edge of your mast without a proper introducer.
The turbulent boundary layer caused by this poorly designed
nose has to reattach itself some distance down the wing.
Doesn't mean there isn't some lift, but the turbulent air is mixing
with air at ambient pressure negating big lift opportunity.

Simple execution does not mean effective.  Reasons for few
commercial attempts with soft wing sails.

JT

--- In harryproa@..., "Robert"
<cateran1949@y...> wrote:
> Elegant simplicity. Does it have a line to the top gaff to control
> twist? Would the top gaff act to some extent as an end plate?
Much as
> I like the simplicity, I can't help wanting to fiddle with it to make
> it go that little bit better.
> How would one of these go with a rotating wing mast to give
finer
> entry and control camber? It would probably require split  or
twinned
> battens though, and outhaul tension controls to do it properly. It
> might be better to go the whole hog and use dynawing foil
inducers
> and their related battens. Or go even further and replace the
top
> gaff with a batten, enclose the area between the top gaff and
the
> mast and you have a dynawing.
> A problem with all these rigs is how to attach stays to their
optimum
> position of ~2/3 of the way up the mast and still allow reefing.
This
> can be overcome with a litle extra weight in stiffening and
attach
> them higher to the mast or even to the sail.
>  I would like to see some boat to boat comparisons of the
various
> rigs on Harryproas, but first we have to get some boats sailing.
> Robert
>
>
>
>
> --- In harryproa@..., "proaconstrictor"
> <proaconstrictor@y...> wrote:
> > --- In harryproa@..., "Robert"
<cateran1949@y...>
> > wrote:
> > > Personally I like the idea of a soft wing sail, in fact I quite
> > like
> > > Wharram's high gaff soft wing
> >
> >
> > Did you catch this?
> >
> > http://www.themultihull.com/woods/ps1.htm

Not sure I see the wing part on this boat.   Soft wing sails are so
hard to execute effectively on a  sailboat, that there are no
successful commercial applications to date.  Several players
with start up efforts but there are significant problems to
overcome.  Try reading Tom Speers article on soft wing
aerodynamics :  http://www.tspeer.com/Wingmasts/mast.htm.
Effective performance does not come two layers of sail cloth on
both side of the mast.   Need an introducer that faces into the
wind while the boom is 20 deg off the wind.  The introducer has
to face the other way after a shunt.  Sail thickness and camber
are not effective unless you can change the effective distance of
travel for the airstream.  Combination of battens and actual shift
in sail material distance to mast attachment is required.

Nobody seems to be ably to do all of this without excessive
weight aloft or high cost.  Naturally reefing is a singular issue
with rigid wings.  I think dynawing comes closest to ideal :
http://www.dynawing.com  however after 17 years of testing they
still do not have a commercial product for whatever reason.  Part
of the problem may have been the omission of the Balestron rig
to overcome some of these issues.  The balestron allows the
wing to pivot downwind which according to Speers is still
creating lift better than a big bag.  The biggest issue for the
belestron is the mast if used as an introducer, faces a direction
different than the boom.  They have to move independently,
boom to set the sail and mast to head into the wind.    All this
does result in higher windage for a mast set with just bare
poles.   Anyway, take this all in as casual reading, especially the
aerodynamics explanation.

Sails have tremendous drag, typical lift to drag ratio of 3:1.  Good
thing you are not trying to fly with them.  A proper designed wing
sail could give better than 10:1 L/D.  Taking in account, non
optimized angles due to sea action and surface imperfections
from stitching, etc., 5:1 L/D is a reasonable performance goal.

Could make for some fast sailing.  Plus the added lift is in the
right vector direction reducing the center of effort, keeping your
WW hull planted in the water.  There may be other issues that
have not surfaced, preventing effective implementation of a
softwing design.  Probably first and foremost is "need" or what
economists call demand.

Lots of problems with these, same goes with some of the other
esoteric wing types.

Regards,

JT


--- In harryproa@..., "proaconstrictor"
<proaconstrictor@y...> wrote:
> --- In harryproa@..., "Robert"
<cateran1949@y...>
> wrote:
> > Personally I like the idea of a soft wing sail, in fact I quite
> like
> > Wharram's high gaff soft wing
>
>
> Did you catch this?
>
> http://www.themultihull.com/woods/ps1.htm

Elegant simplicity. Does it have a line to the top gaff to control
twist? Would the top gaff act to some extent as an end plate? Much as
I like the simplicity, I can't help wanting to fiddle with it to make
it go that little bit better.
How would one of these go with a rotating wing mast to give finer
entry and control camber? It would probably require split  or twinned
battens though, and outhaul tension controls to do it properly. It
might be better to go the whole hog and use dynawing foil inducers
and their related battens. Or go even further and replace the top
gaff with a batten, enclose the area between the top gaff and the
mast and you have a dynawing.
A problem with all these rigs is how to attach stays to their optimum
position of ~2/3 of the way up the mast and still allow reefing. This
can be overcome with a litle extra weight in stiffening and attach
them higher to the mast or even to the sail.
  I would like to see some boat to boat comparisons of the various
rigs on Harryproas, but first we have to get some boats sailing.
Robert




--- In harryproa@..., "proaconstrictor"
<proaconstrictor@y...> wrote:
> --- In harryproa@..., "Robert" <cateran1949@y...>
> wrote:
> > Personally I like the idea of a soft wing sail, in fact I quite
> like
> > Wharram's high gaff soft wing
>
>
> Did you catch this?
>
> http://www.themultihull.com/woods/ps1.htm