Did some rough calculations on the Harryproas stability at 90 degrees.
Empty, a Harry is stable on its side but not by a large margin.
Probably the resistance of the masts as well as the bouyancy would stop
it turning over. Loaded, IFF the loads are well placed the situation
improves. An extra 40kg or so bouyancy at the masthead and there is big
improvement. Possibly soft urethane foam sewn ito the top panel of the
sail would do. With wing masts the margin is much larger.
Regards
Robert

I agree, with the points regarding the benefits of the leepod.

As for recovery in case of a capsize, I tend to favour the ama
flooding idea. Having heavy equipment like engine and anchor tackle
to ww would probabely sink a completely flooded ama. Need to choose
non very buoyant building technique. Denser material would fit better.

Once having sunk the ama, the crew would be able to retrieve a
halyard or running backstay to lever the ama up again, on the other
side. Using the mast as lever. Using fenders and other buoyant stuff
as fixed point. Maybe a dedicated rightening buoy. A reasonable
reduction on the running backstay. In this case the leepod would even
be beneficial givin a better, outward angle to the masttop.

All this calls for:
- a non too buoyantly built ama without reserve/emergeny buoyancy.
Unless its removable in case of capsize... good idea. It might be the
later used rightening buoy. Inflated, flexible water containers.
- a non too buoyant aka construction.
- an effective way to flood the ama.
- only little buoyancy of the cabin to of the hulls gunwahle, so to
ww. Assuming that the cabin would be on the vaka, not ama. ´Cause if
it were to ww and on ama, why would you want a leepod anyway?
- Enough weight to sink the ama,
- some reserve buoyancy in the vaka, to keep it floating even flooded,
- A good bailing bucket. to get the boat dry again.
- A reasonabely fit crew and moderate weather.

Might seem like a long list to most. But it does not sound impossible
to me. On the contrary.

Peter






--- In harryproa@..., Mike Crawford <jmichael@g...>
wrote:
>
> >
> > "In breaking seas, if hit from the side by a breaking wave it
could
> > dig in and flip the boat."
> >
> > Not heard of that happening, doesn't seem to be a serious
objection.
>
>
>   This is probably more of a problem in theory than in practice,
but
> hey, that's why we're all here batting the ideas about.
>
>   Leeward-pod proas have been through some pretty heavy weather, so
we
> know they can be seaworthy in good hands.  I still like to keep
> challenging the design, though, to eliminate as many potential
problems
> as possible.
>
>
> > "It also makes the boat less likely to be stabilised by mast
bouyancy
> > from going over further."
> >
> > Right, stabilizing with mast bouyancy is not what one wants in
the
> > kind of situation that causes a capsize in the first place.
> > Self-righting is the proven concept
>
>   Could you explain this in more detail?  I think that self-
righting is
> a wonderful thing, but don't yet see how a leeward-pod proa would
right
> itself in a knockdown or wave-induced capsize.
>
>   Rob's explanation of a harryproa recovery makes sense: the boat
floats
> at 90 degrees supported by mast buoyancy, the windward hull
weathercocks
> to leeward, and then a kite or weight is used to pull the windward
hull
> back down.  I wouldn't want to try it on a bad day, but at least
it's
> possible.  Something like that would never, ever happen on most
cruising
> cats.
>
>   I can see how the leeward-pod proa will work well for a wind-
induced
> capsize, especially if the knockdown isn't complete.  Forgetting
the
> rig, that pod will keep the boat from going over in many or most
cases,
> so there's no need to worry about mast buoyancy.
>
>   But what about a more extreme condition, such as a massive gust,
a
> large steep wave, or a combination of the two?  If something were
to
> push a leeward-pod proa past 90 degrees, how could it be righted
again?
> I would think that anything that extends past the hull would make
it
> more difficult to flip the boat back upright..
>
>   It seems to me that a) the harryproa will normally have a greater
> righting moment when sailing,  b) while the leeward-pod proa will
be
> more resistant to capsize if you push the boat past 30 degrees, but
c)
> the harryproa will have a much greater chance of getting back on
its
> feet if pushed to 90 degrees.
>
>   It's a series of tradeoffs  I like the harryproa approach, but
I'm
> clearly biased.  However, if I can learn how a leeward-pod proa
will
> self-right, that could certainly change things.
>
>        - Mike
>
>
>
> proaconstrictor wrote:
>
> > "My objection wasn't with the Pacific proa. I have great fondness
for
> > it after my time in PNG. I believe it has its place but not for
long
> > haul cruising."
> >
> > That is a fair point, but it falls into the same category as a
cruise
> > ship passenger wondering why someone would cruise on any sailing
> > multihull.  Russ Brown doesn't recomend that you or I do it, you
have
> > to want to do it for whatever wacky reason.
> >
> >
> > "My objection is the use of the lee pod as I believe
> > that it is an unseaworthy attachment. I can almost see some value
in
> > it for flat seas as training wheels and as a lee platform for
> > drifting conditions but not once there is any swell. I can't see
how
> > it can help prevent combination wind/wave capsize."
> >
> > Right answer, wrong question.  It's not aobut capsize, but self-
> > righting, and it doesn't prevent knock down it just rights from
it.
> >
> > "On the side of a wave the boat would have to be about 90 degrees
> > before the leepod contributed to righting moment."
> >
> > Right at the point where a PP without one might become stable in
the
> > knock down position, it is doing it's work.  Somewhat similar to
what
> > ballast does in the same situatiom.
> >
> > "In breaking seas, if hit from the
> > side by a breaking wave it could dig in and flip the boat."
> >
> > Not heard of that happening, doesn't seem to be a serious
objection.
> > Reminds me of the Wharram/Boon drawing of a tri perched ona
rbeaking
> > wave about to get rolled over.  It might happen, but it either
> > doesn't or they have the sea anchor out, one hopes the literature
is
> > not full of that kind of capsize.
> >
> > There isn't much evidence of the pods digging in either, depends
on
> > the exact shape, but generally they seem to rise out of a wave.
> >
> >
> > "It also
> > makes the boat less likely to be stabilised by mast bouyancy from
> > going over further."
> >
> > Right, stabilizing with mast bouyancy is not what one wants in the
> > kind of situation that causes a capsize in the first place.  Self-
> > righting is the proven concept, or as with conventional cruising
> > multis a very high resistance to capsize.  Low resistance to
capsize
> > combined with high stability in the capsized or KD position is
not a
> > winner.
> >
> >
> >
> >
> > ------------------------------------------------------------------
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> >
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subject=Unsubscribe>
> >
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> >       Service <http://au.docs.yahoo.com/info/terms/>.
> >
> >
>

"In breaking seas, if hit from the side by a breaking wave it could dig in and flip the boat."

Not heard of that happening, doesn't seem to be a serious objection.

"It also makes the boat less likely to be stabilised by mast bouyancy from going over further."

Right, stabilizing with mast bouyancy is not what one wants in the  kind of situation that causes a capsize in the first place.  Self-righting is the proven concept

"My objection wasn't with the Pacific proa. I have great fondness for
it after my time in PNG. I believe it has its place but not for long
haul cruising."

That is a fair point, but it falls into the same category as a cruise
ship passenger wondering why someone would cruise on any sailing
multihull.  Russ Brown doesn't recomend that you or I do it, you have
to want to do it for whatever wacky reason.


"My objection is the use of the lee pod as I believe
that it is an unseaworthy attachment. I can almost see some value in
it for flat seas as training wheels and as a lee platform for
drifting conditions but not once there is any swell. I can't see how
it can help prevent combination wind/wave capsize."

Right answer, wrong question.  It's not aobut capsize, but self-
righting, and it doesn't prevent knock down it just rights from it.

"On the side of a wave the boat would have to be about 90 degrees
before the leepod contributed to righting moment."

Right at the point where a PP without one might become stable in the
knock down position, it is doing it's work.  Somewhat similar to what
ballast does in the same situatiom.

"In breaking seas, if hit from the
side by a breaking wave it could dig in and flip the boat."

Not heard of that happening, doesn't seem to be a serious objection.
Reminds me of the Wharram/Boon drawing of a tri perched ona  rbeaking
wave about to get rolled over.  It might happen, but it either
doesn't or they have the sea anchor out, one hopes the literature is
not full of that kind of capsize.

There isn't much evidence of the pods digging in either, depends on
the exact shape, but generally they seem to rise out of a wave.


"It also
makes the boat less likely to be stabilised by mast bouyancy from
going over further."

Right, stabilizing with mast bouyancy is not what one wants in the
kind of situation that causes a capsize in the first place.  Self-
righting is the proven concept, or as with conventional cruising
multis a very high resistance to capsize.  Low resistance to capsize
combined with high stability in the capsized or KD position is not a
winner.

Robert,

I for one have given the lee pod some thought of late based on your
descriptions of its functioning.  I never questioned its performance and
just accepted that it would help prevent capsize.  Your point is a good
one whether valid or not and you have given me the tools to access the
concept on my own....   That is why I value this forum so much .....
Again, the opposing view to your point is just as important to me in
accessing the pod and its functioning. I would personally like to see
this thread continue for a while also hoping that someone does not turn
up the fire too high and make the pot boil over putting this threads fire
out.  Every aspect of boat design must be questioned until each facet is
fully understood by the designer and then reconsidered at regular
intervals even after the ink dries.  Every boat design is one big
compromise and can never be correct or perfect. The best designers
continue to tweek their last attempts into a better compromise to reach
the sweet carrot of perfection, that must always continue, just out of
reach.  I thank ... All ... contributors to this thread.

John "Compass"


On Mon, 30 Jan 2006 12:22:59 -0000 "Robert" <cateran1949@...>
writes:
> --- In harryproa@..., "proaconstrictor"
> <proaconstrictor@y...> wrote:
> >
> > "My objection wasn't with the Pacific proa. I have great fondness
>
> for
> > it after my time in PNG. I believe it has its place but not for
> long
> > haul cruising."
> >
> > That is a fair point, but it falls into the same category as a
> cruise
> > ship passenger wondering why someone would cruise on any sailing
> > multihull.  Russ Brown doesn't recomend that you or I do it, you
> have
> > to want to do it for whatever wacky reason.
> >
> Fair comment
>
>
> > "My objection is the use of the lee pod as I believe
> > that it is an unseaworthy attachment. I can almost see some value
> in
> > it for flat seas as training wheels and as a lee platform for
> > drifting conditions but not once there is any swell. I can't see
> how
> > it can help prevent combination wind/wave capsize."
> >
> > Right answer, wrong question.  It's not aobut capsize, but self-
> > righting, and it doesn't prevent knock down it just rights from
> it.
> >
> > "On the side of a wave the boat would have to be about 90 degrees
>
> > before the leepod contributed to righting moment."
> >
> > Right at the point where a PP without one might become stable in
> the
> > knock down position, it is doing it's work.  Somewhat similar to
> what
> > ballast does in the same situatiom.
>
> This is where we have a difference of opinion
> On a side of a wave by the time the leepod STARTS to work the boat
> is
> pretty close to 90 degrees, not when it has any significant
> bouyancy.
> By the time it provides significant bouyancy you are probably past
> dead center and by the time the rig slows you down you're over and
> the leepod is actually preventing the return.
> This is my interpretation of the mathematics.
>
>
>
>
> >
> > "In breaking seas, if hit from the
> > side by a breaking wave it could dig in and flip the boat."
> >
> > Not heard of that happening, doesn't seem to be a serious
> objection.
> > Reminds me of the Wharram/Boon drawing of a tri perched ona
> rbeaking
> > wave about to get rolled over.  It might happen, but it either
> > doesn't or they have the sea anchor out, one hopes the literature
>
> is
> > not full of that kind of capsize.
>
>
> There are not many leepod boats out there in Bass Strait conditions.
>
> My experience of breaking seas over many years in pretty nasty
> conditions coupled with my experience surfing all sorts of craft
> (including many capsizes in craft that weren't meant to be surfed)
> suggests it is a real possibility.
> This could be tested by making a scale model of a PP with a leepod
> and taking it down to a beach with a small to moderate surf. I am
> sufficiently convinced by the mathematics and my own experience to
> think that a leepod is at best useless, except in flat seas and at
> worst a trigger for a full capsize
>
> If my reasoning doesn't make sense to you , so be it, but at least
> it
> is out there for people to at least think about.
>
> >
> > There isn't much evidence of the pods digging in either, depends
> on
> > the exact shape, but generally they seem to rise out of a wave.
> > "It also
> > makes the boat less likely to be stabilised by mast bouyancy from
> > going over further."
> >
> > Right, stabilizing with mast bouyancy is not what one wants in the
>
> > kind of situation that causes a capsize in the first place.
> Self-
> > righting is the proven concept, or as with conventional cruising
> > multis a very high resistance to capsize.  Low resistance to
> capsize
> > combined with high stability in the capsized or KD position is not
>
> a
> > winner.
> >
> Who said anything about low resistance to capsize. Again my argument
>
> is that the lee pod does not prevent capsize on the side of a
> moderately steep wave and encourages the boat to go way past 90 in
> this situation, preventing its return back to 90. Wouldn't it be
> better to be stabilised at 90 degrees in that situation?
>
> I am sorry if my explanation is not clear enough as the mathematics
>
> are clear enough for me.
>
>
> Regards,
> Robert
>
>
>
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>

----- Original Message -----

From: dominiquebovey

To: harryproa@...

Sent: Monday, January 30, 2006 3:18 AM

Subject: [harryproa] Re: 8.5m multi "box rule"

Rob, the 2006 Bol d'Or will be June 17-18.
Ready for 93 miles of lake racing?
I also do not think we'll have a chance against the M2s with the EL,
but hey, it will be fun. I only hope there will be more wind than in
2005. You're welcome to stay over at our place, naturally.

I agree about the importance of mast height, as limited as it is in
the M2 class to a meagre 16.6m ;-) Most racing boats here have mains
that are almost square. But nobody does it with unstayed una rigs,
because you absolutely need big reachers. A main only has not enough
sail area. And I do still believe, as most havigators here, in the
positive effect of a jib in front of the main.

I do not quite see how you can telescope a mast, even an unstayed one,
when sailing. Do you mean you do you do this at the harbour, or even
prior to assembling the boat? And how does the wing mast make this
easier vs. the round mast?

I am not sure the "extra height" is a problem in the breeze. IMHO once
you've taken a reef, the upper section adds some sail area high up,
but this is not so much of a problem.
There is the problems of surviving the 45kn of a thunderstorm. Wind
usually builds up to this speed from flat calm in 2-3 minutes, so you
better take all sails down - fast! And ideally a seasoned crew should
be able to keep the boat upright with a bare rig, for the 30-45min
this lasts. But if the boat capsizes, then you can wait for some power
boat to pull you upright (or gather the remains of the boat). On this
lake you're never more than 4nm offhore at its widest. In order not to
be washed ashore (which is mostly steep and rocky) you even ought to
capsize!

--- In harryproa@..., "Rob Denney" <proa@i...> wrote:
>
> G'day,
>
> When is the Bol d'Or this year?  Would be glad to sail it with you
of we can get the boat to and from Belgium to Switzerland.   Fun would
be no problem, beating the M2's may be.
>
> A una rigged El with carbon/nomex, pressure moulded everything looks
like it will be near enough 90 kgs.    An 8.5m would be less than 150%
of this
>
> For light air sailing mast height is everything (see Bethwaites
book) as wind strength increases rapidly with height.  Therefore the
highest mast possible would be the aim, rather than the largest sail
area.  The problem then becomes what to do with the extra height in a
breeze.  One possibility with a mast with no external fittings
(forestay, wishbone, etc) is a telescoping mast.  Doing this with a
round mast is pretty difficult, but with a wing mast  it would a lot
easier.  Would not be as quick as hoisting/dousing a headsail, but in
a race where it is either windy or not, it has some potential. 
>
> regards,
>
> rob   ----- Original Message -----
>   From: dominiquebovey
>   To: harryproa@...
>   Sent: Thursday, January 26, 2006 1:24 PM
>   Subject: [harryproa] Re: 8.5m multi "box rule"
>
>
>   Rob,
>   I am DEFINITELY interested to sail the Elementarry, and yes you're
>   probably right, do the bol d'Or unofficially with a crew of two.
>   One one the goals is putting my company name on the sails o hulls, and
>   even unofficially it will get some media coverage... The main goal
>   being to have fun!
>   The 8.5m EL would be less than 200kg racing, the 8.5m cats weigh a
>   little less than 400kg, so EL needs about 2x less sail area for the
>   same sail/displ ratio, Hence the Melges sails. Also a way to limit
costs.
>   But it might be possible to find sails designed for the 8.5m, therefor
>   DOUBLING the ratio! Might be overkill, and difficult engineeringwise.
>
>   --- In harryproa@..., "Rob Denney" <proa@i...> wrote:
>   >
>   > G'day,
>   >
>   > Fixed length is not a proa strong point.  I am not sure whether the
>   weight and windage savings possible with a proa would offset that or
>   not.  It would certainly cost a lot less.  I would love to have a go
>   at designing something for it..   There are a few areas that proas can
>   exploit that are not open to cats.  
>   >
>   > Maybe wait and see how the Elementarry being built in Belgium goes
>   against the Tornados (this summer, I hope)  and then look at what
>   should be scaled up and what can be reduced.  Incidentally, I will not
>   be competing in  the Bol d'Or (hope to be racing Blind Date in
>   Denmark), but the boat is available for charter if you or anyone is
>   interested.  I would advise that you do it unofficially with two crew,
>   rather than officially with three. 
>   >
>   > Could you let us know the beam, mast height and sail area of the M2
>   class, please.  On the web page it looked like 70 sqm upwind, plus a
>   similar size screecher, but this does not tally with the Melges sails.
>   On this subject, I think the melges sails would be too light, and not
>   of optimum plan form for a light air boat which would have a near
>   rectangular main. 
>   >
>   > regards,
>   >
>   > rob
>   >
>   >
>   >   Sorry for misquoting, David mentioned this box rule naturally.
>   >
>   >   Yes these crazy boats are incredible, I have seen them flying
a hull
>   >   on flat water, 8kn of speed with 5kn of wind. They work by
creating
>   >   their apparent wind. But their top speed is estimated at 30kn.
>   >
>   >   The last horrible wind-less Bol d'Or was done with "winds
averaging 3
>   >   knots", the winner took 18 hours for the 100 miles. That is
beyond my
>   >   nerves anyway.
>   >
>   >   There are two classes. the M1 (only Decision 35 today) are
machines
>   >   costing half a million swiss francs (about the same in AUD),
with a
>   >   racing budget of maybe half that on top of it every year. The
pre-preg
>   >   hull skin is less tha a millimeter thick...
>   >   And they are low cost machines versus the f40 they had before!
A very
>   >   well known owner of D35 is bertarelli, yes the poor guy who owns
>   >   alinghi and the america cup... Well I do not have any prospect of
>   >   competing (financially) for some time to come, even if I am a
rather
>   >   optimistic type.... But this might be a job for a Turbo-Harrigami.
>   >
>   >   But there is the M2 class, and the M2 are much more
"accessible" (for
>   >   a catamaran, around 100kCHF). The M2 are very close in
performance to
>   >   the M1, and I would be very happy to be in the 10 first of the Bol
>   >   d'Or to start...
>   >
>   >   A HarryM2 would probably cost much less than that (Rob, am I
right?),
>   >   because of the structural advantage, and would be competitive with
>   >   much less high tech gear than the cats and tris in this class. It
>   >   would be nice to be competitive with wood-epoxy hulls and
minimal use
>   >   of carbon (only rig and beams), against all-carbon-kevlar racing
>   >   machines. Kind of David against Goliath. But David still needs
a good
>   >   slingshot! And HarryM2 would still need a lot a sail.
>   >
>   >   To decrease cost while keeping good performance, I am
wondering if the
>   >   whole rig for an 8.5m can be built around "standard" sails. For
>   >   example, a melges 24 sail plan (24m2 main, 10m2 jib), of which you
>   >   find (not very much) used sails for reasonable prices, while only
>   >   needing to recut the jib a bit.
>   >
>   >   --- In harryproa@..., Mike Crawford <jmichael@g...>
>   wrote:
>   >   >
>   >   >
>   >   >   I think it was David Howie who wrote about the box rule, and
>   it just
>   >   > shows up in my posts because I keep on replying in the same
thread.
>   >   >
>   >   >   Any ideas David?
>   >   >
>   >   >   BTW, If I wanted to race on Lake Geneva, I'd be much more
>   likely to
>   >   > want something like those Décision 35's for which you provided a
>   >   link.. 
>   >   > That was you, Dominique, wasn't it?  In any case, I'm astounded
>   by the
>   >   > sail area carried by those boats, and am truly amazed with the
>   video
>   >   > that shows them flying hulls and sailing at speed without a
single
>   >   > whitecap to be seen.  I'd simply love to sail one for a few
days.
>   >   >
>   >   >   Those boats are way too finicky and fragile for something I'd
>   get,
>   >   > provided I could afford one in the first place, but there's no
>   denying
>   >   > that they are masterful speed machines, especially for light
air.
>   >   While
>   >   > I love the schooner rig with flexible unstayed masts, I'm
>   viewing this
>   >   > from the perspective of racing single-handed in gusty
>   conditions.  In a
>   >   > real race, in low wind, with crews that know what they are
>   doing, I'd
>   >   > have a hard time imagining anything beating  a Décision 35.
>   >   >
>   >   >   I don't truly want one of those fast cats for a variety of
>   reasons,
>   >   > but they sure do make me drool.  I'm going to go look at some
>   Décision
>   >   > 35 photos now, and maybe watch that video again.
>   >   >
>   >   >
>   >   >        - Mike
>   >   >
>   >   >
>   >   >
>   >   > dominiquebovey wrote:
>   >   >
>   >   > > Hi,
>   >   > > Mike just wrote about an 8.5m "box rule". On Lake Geneva,
>   switzerland,
>   >   > > there are two multihull classes, M1 (10.8m hull length,
>   >   > > Alinghi/Bertarelli is doing this) and M2 (8.5m), see this
link:
>   >   > > http://www.regates.ch/index.asp?ID=354.
>   >   > > My conceptions of rig stiffness are somehow influenced by
the sail
>   >   > > areas you see on the diagram... And lake geneva is terrible
>   for wind,
>   >   > > with most summer races in ghosting conditions (including
the "bold
>   >   > > d'or"), but in spring and fall there can be quite a lot of
wind.
>   >   > > What is the "box rule" you are talking about,Mike?
>   >   > >
>   >   > >
>   >   >
>   >
>   >
>   >
>   >
>   >
>   >
>   >
> 
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>      
>     b.. To unsubscribe from this group, send an email to:
>     harryproa-unsubscribe@...
>      
>     c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.
>

My sentiments exactly. It seems to me the time taken for a boat is
proportion to the fiddly bits more than the size. It doesn't take
that much more time making a 2m panel as a 1m, though the costs of
materials goes up with the cube of the length and there are probably
more fiddly bits on a bigger boat. I'm certainly looking at getting
the masts built if there is only that marginal difference from the
self build. Might be time to hassle about getting the pictures of
Bain's Harry either in the files or on the website(sorry Mark and
michelle ;-))--- In harryproa@..., David Howie <dana-
tenacity@u...> wrote:
>
>
> Lol, when I first mentioned the R33 it was a bit tongue in cheek,
but I'm
> enjoying the responses. For what it's worth he seems to have built
a decent
> light cat, then stuck a huge rig on it and said look how fast it
is. Not
> hugely sophisticated but one way of doing it. I think the Harry
approach is
> more subtle, and is actually a new way of doing things.
> For what it's worth I'm drifting back towards the idea of a
schooner rig, but
> it was always my intention with the schooner to run a halyard out
the front of
> the masts around 3/4 height for a free flying staysail/screacher
for light
> airs and running. (Sheet off the end of the wishbone?)
> When I first found this site I was getting ready to start a smaller
project as
> practice for a bigger real boat. Now I'm wondering whether or not
to just jump
> in the deep end and do the Harry thing instead of wasting time and
money on a
> boat that isn't the one I want to end up with. Still it's a big
project for me
> in a number of ways ( not least financial). Got about two months to
decide as
> I was going to start after the last big A class regatta for the
year.
> ------ Original Message ------
> Received: Sun, 29 Jan 2006 04:22:33 PM MST
> From: "Robert" <cateran1949@y...>
> To: harryproa@...
> Subject: [harryproa] Re: Reynolds 33
>
> Agreed. If I wanted to inshore race a harry I'd go for two tall
> skinny  square topped sails with wingmasts and sail it like an
> Elementarry, (Including the righting pole ;-)). I figure that if
you
> have the righting ability and the fore aft stability then you can
> somehow get the extra sail area. Theoretically, a Harry loaded,
> giving 50% more righting moment should allow a 20% higher rig and
as
> you are sailing upwind all the time, its the lengths of those luffs
> that count. Or you can leave it light and have a similar height rig
> trimming for the main wind strength and allowing the flex of the
> masts depower for the gusts. The long  bows with low down bouyancy
of
> the lw hull allow a harry to use its righting moment. Offshore I
may
> be a bit more consevative and have a kite to send up to catch the
> breeze. Theoretically you can work the kite to get more swept area
> instead of tacking down wind. And if you had four crew you could
take
> it in turns to sip the iced tea --- In
harryproa@...,
> Mike Crawford <jmichael@g...> wrote:
> >
> >
> >   I test sailed the R33, and it is indeed a very fast and boat.
> With
> > its tall mast and huge code 0 on the bowsprit, it's particularly
> good in
> > light air.  The design is a bit funky with that backrest, but
it's
> > really nice to lean back and sail when everything is set just
> right.  It
> > was an amazing value for $40,000 US (minus sails) when it was
first
> > advertised.  Now that it's closer to $140,000 US fully-rigged,
it's
> not
> > quite such a value any more.
> >
> >   I chose a used Stiletto 27 instead of the Reynolds, partially
> because
> > it's nice to have a removable hard cockpit deck, and partially
> because
> > the entire boat could be had for the cost of a down payment on
the
> R33.
> >
> >   A Harry should be able to compete with an R33, but that would
> require
> > some effort.  You'd need either a really tall mast, a schooner
rig,
> > headsails, or a combination of the three.  The R33 would lack the
> > Harry's righting moment, but it sure does have an awesome amount
of
> sail
> > area for its weight.  Not quite like the Décision 35's, but still
a
> lot
> > of canvas.
> >
> >   For the same price as an R33, you could have a really fast
harry
> that
> > would include a head, galley, standing headroom, and two double
> bunks.
> > The Harry would also be a lot easier to sail, will probably be
> safer,
> > and should be faster in some wind conditions.  If you wanted to
> race
> > against the R33, though, you'd have to go past the standard easy
> rig.
> > It could be done, but you'd have to spend more time pulling
strings
> and
> > less time sipping that ice cold drink.
> >
> >        - Mike
> >
> >
> >
> > Robert wrote:
> >
> > > Don't know about a Reynolds 33 at 'only 3000lbs' being
necessarily
> > > faster . A 40'lw hull harry weighs not much more than half of
> that. You
> > > can pile your stores in the ww hull to bring it to the same
> weight and
> > > you have 50% more righting moment and a longer waterline length
> with
> > > higher prismatic coefficient for the hull with the load on it
so
> you
> > > can push it harder before pichpoling. This 3000lb is not much
> less than
> > > the 3700lbs for 50' Visionary, a cruiser built in strip plank.
> > > Sometimes I wonder at the figures for Harry designs in contrast
> with
> > > catamarans and tris and try to work out where the differences
are
> but
> > > there are now five built and the reality confirms the estimated
> weights.
> > > regards,
> > > Robert
> > >
> > >
> > >
> > >
> > > ----------------------------------------------------------------
--
> ------
> > > *Yahoo! Groups Links*
> > >
> > >     * To visit your group on the web, go to:
> > >       http://au.groups.yahoo.com/group/harryproa/
> > >
> > >     * To unsubscribe from this group, send an email to:
> > >       harryproa-unsubscribe@...
> > >       <mailto:harryproa-unsubscribe@...?
> subject=Unsubscribe>
> > >
> > >     * Your use of Yahoo! Groups is subject to the Yahoo! Terms
of
> > >       Service <http://au.docs.yahoo.com/info/terms/>.
> > >
> > >
> >
>

--- In harryproa@..., "proaconstrictor"
<proaconstrictor@y...> wrote:
>
> "My objection wasn't with the Pacific proa. I have great fondness
for
> it after my time in PNG. I believe it has its place but not for long
> haul cruising."
>
> That is a fair point, but it falls into the same category as a
cruise
> ship passenger wondering why someone would cruise on any sailing
> multihull.  Russ Brown doesn't recomend that you or I do it, you
have
> to want to do it for whatever wacky reason.
>
Fair comment


> "My objection is the use of the lee pod as I believe
> that it is an unseaworthy attachment. I can almost see some value in
> it for flat seas as training wheels and as a lee platform for
> drifting conditions but not once there is any swell. I can't see how
> it can help prevent combination wind/wave capsize."
>
> Right answer, wrong question.  It's not aobut capsize, but self-
> righting, and it doesn't prevent knock down it just rights from it.
>
> "On the side of a wave the boat would have to be about 90 degrees
> before the leepod contributed to righting moment."
>
> Right at the point where a PP without one might become stable in
the
> knock down position, it is doing it's work.  Somewhat similar to
what
> ballast does in the same situatiom.

This is where we have a difference of opinion
On a side of a wave by the time the leepod STARTS to work the boat is
pretty close to 90 degrees, not when it has any significant bouyancy.
By the time it provides significant bouyancy you are probably past
dead center and by the time the rig slows you down you're over and
the leepod is actually preventing the return.
This is my interpretation of the mathematics.




>
> "In breaking seas, if hit from the
> side by a breaking wave it could dig in and flip the boat."
>
> Not heard of that happening, doesn't seem to be a serious
objection.
> Reminds me of the Wharram/Boon drawing of a tri perched ona
rbeaking
> wave about to get rolled over.  It might happen, but it either
> doesn't or they have the sea anchor out, one hopes the literature
is
> not full of that kind of capsize.


There are not many leepod boats out there in Bass Strait conditions.
My experience of breaking seas over many years in pretty nasty
conditions coupled with my experience surfing all sorts of craft
(including many capsizes in craft that weren't meant to be surfed)
suggests it is a real possibility.
This could be tested by making a scale model of a PP with a leepod
and taking it down to a beach with a small to moderate surf. I am
sufficiently convinced by the mathematics and my own experience to
think that a leepod is at best useless, except in flat seas and at
worst a trigger for a full capsize

If my reasoning doesn't make sense to you , so be it, but at least it
is out there for people to at least think about.

>
> There isn't much evidence of the pods digging in either, depends on
> the exact shape, but generally they seem to rise out of a wave.
> "It also
> makes the boat less likely to be stabilised by mast bouyancy from
> going over further."
>
> Right, stabilizing with mast bouyancy is not what one wants in the
> kind of situation that causes a capsize in the first place.  Self-
> righting is the proven concept, or as with conventional cruising
> multis a very high resistance to capsize.  Low resistance to
capsize
> combined with high stability in the capsized or KD position is not
a
> winner.
>
Who said anything about low resistance to capsize. Again my argument
is that the lee pod does not prevent capsize on the side of a
moderately steep wave and encourages the boat to go way past 90 in
this situation, preventing its return back to 90. Wouldn't it be
better to be stabilised at 90 degrees in that situation?

I am sorry if my explanation is not clear enough as the mathematics
are clear enough for me.


Regards,
Robert

----- Original Message -----

From: David Howie

To: harryproa@...

Sent: Monday, January 30, 2006 4:13 PM

Subject: Re: [harryproa] Re: Reynolds 33

Lol, when I first mentioned the R33 it was a bit tongue in cheek, but I'm
enjoying the responses. For what it's worth he seems to have built a decent
light cat, then stuck a huge rig on it and said look how fast it is. Not
hugely sophisticated but one way of doing it. I think the Harry approach is
more subtle, and is actually a new way of doing things.
For what it's worth I'm drifting back towards the idea of a schooner rig, but
it was always my intention with the schooner to run a halyard out the front of
the masts around 3/4 height for a free flying staysail/screacher for light
airs and running. (Sheet off the end of the wishbone?)
When I first found this site I was getting ready to start a smaller project as
practice for a bigger real boat. Now I'm wondering whether or not to just jump
in the deep end and do the Harry thing instead of wasting time and money on a
boat that isn't the one I want to end up with. Still it's a big project for me
in a number of ways ( not least financial). Got about two months to decide as
I was going to start after the last big A class regatta for the year.
------ Original Message ------
Received: Sun, 29 Jan 2006 04:22:33 PM MST
From: "Robert" <cateran1949@...>
To: harryproa@...
Subject: [harryproa] Re: Reynolds 33

Agreed. If I wanted to inshore race a harry I'd go for two tall
skinny  square topped sails with wingmasts and sail it like an
Elementarry, (Including the righting pole ;-)). I figure that if you
have the righting ability and the fore aft stability then you can
somehow get the extra sail area. Theoretically, a Harry loaded,
giving 50% more righting moment should allow a 20% higher rig and as
you are sailing upwind all the time, its the lengths of those luffs
that count. Or you can leave it light and have a similar height rig
trimming for the main wind strength and allowing the flex of the
masts depower for the gusts. The long  bows with low down bouyancy of
the lw hull allow a harry to use its righting moment. Offshore I may
be a bit more consevative and have a kite to send up to catch the
breeze. Theoretically you can work the kite to get more swept area
instead of tacking down wind. And if you had four crew you could take
it in turns to sip the iced tea --- In harryproa@...,
Mike Crawford <jmichael@g...> wrote:
>
>
>   I test sailed the R33, and it is indeed a very fast and boat. 
With
> its tall mast and huge code 0 on the bowsprit, it's particularly
good in
> light air.  The design is a bit funky with that backrest, but it's
> really nice to lean back and sail when everything is set just
right.  It
> was an amazing value for $40,000 US (minus sails) when it was first
> advertised.  Now that it's closer to $140,000 US fully-rigged, it's
not
> quite such a value any more.
>
>   I chose a used Stiletto 27 instead of the Reynolds, partially
because
> it's nice to have a removable hard cockpit deck, and partially
because
> the entire boat could be had for the cost of a down payment on the
R33.
>
>   A Harry should be able to compete with an R33, but that would
require
> some effort.  You'd need either a really tall mast, a schooner rig,
> headsails, or a combination of the three.  The R33 would lack the
> Harry's righting moment, but it sure does have an awesome amount of
sail
> area for its weight.  Not quite like the Décision 35's, but still a
lot
> of canvas.
>
>   For the same price as an R33, you could have a really fast harry
that
> would include a head, galley, standing headroom, and two double
bunks. 
> The Harry would also be a lot easier to sail, will probably be
safer, 
> and should be faster in some wind conditions.  If you wanted to
race
> against the R33, though, you'd have to go past the standard easy
rig. 
> It could be done, but you'd have to spend more time pulling strings
and
> less time sipping that ice cold drink.
>
>        - Mike
>
>
>
> Robert wrote:
>
> > Don't know about a Reynolds 33 at 'only 3000lbs' being necessarily
> > faster . A 40'lw hull harry weighs not much more than half of
that. You
> > can pile your stores in the ww hull to bring it to the same
weight and
> > you have 50% more righting moment and a longer waterline length
with
> > higher prismatic coefficient for the hull with the load on it so
you
> > can push it harder before pichpoling. This 3000lb is not much
less than
> > the 3700lbs for 50' Visionary, a cruiser built in strip plank.
> > Sometimes I wonder at the figures for Harry designs in contrast
with
> > catamarans and tris and try to work out where the differences are
but
> > there are now five built and the reality confirms the estimated
weights.
> > regards,
> > Robert
> >
> >
> >
> >
> > ------------------------------------------------------------------
------
> > *Yahoo! Groups Links*
> >
> >     * To visit your group on the web, go to:
> >       http://au.groups.yahoo.com/group/harryproa/
> >       
> >     * To unsubscribe from this group, send an email to:
> >       harryproa-unsubscribe@...
> >       <mailto:harryproa-unsubscribe@...?
subject=Unsubscribe>
> >       
> >     * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
> >       Service <http://au.docs.yahoo.com/info/terms/>.
> >
> >
>

PS, I love all the word plays on proa, just figured that I live in
Whangaparaoa, I could put my hailing port on the Stern????? as Whangaproa.

Lol, when I first mentioned the R33 it was a bit tongue in cheek, but I'm
enjoying the responses. For what it's worth he seems to have built a decent
light cat, then stuck a huge rig on it and said look how fast it is. Not
hugely sophisticated but one way of doing it. I think the Harry approach is
more subtle, and is actually a new way of doing things.
For what it's worth I'm drifting back towards the idea of a schooner rig, but
it was always my intention with the schooner to run a halyard out the front of
the masts around 3/4 height for a free flying staysail/screacher for light
airs and running. (Sheet off the end of the wishbone?)
When I first found this site I was getting ready to start a smaller project as
practice for a bigger real boat. Now I'm wondering whether or not to just jump
in the deep end and do the Harry thing instead of wasting time and money on a
boat that isn't the one I want to end up with. Still it's a big project for me
in a number of ways ( not least financial). Got about two months to decide as
I was going to start after the last big A class regatta for the year.
------ Original Message ------
Received: Sun, 29 Jan 2006 04:22:33 PM MST
From: "Robert" <cateran1949@...>
To: harryproa@...
Subject: [harryproa] Re: Reynolds 33

Agreed. If I wanted to inshore race a harry I'd go for two tall
skinny  square topped sails with wingmasts and sail it like an
Elementarry, (Including the righting pole ;-)). I figure that if you
have the righting ability and the fore aft stability then you can
somehow get the extra sail area. Theoretically, a Harry loaded,
giving 50% more righting moment should allow a 20% higher rig and as
you are sailing upwind all the time, its the lengths of those luffs
that count. Or you can leave it light and have a similar height rig
trimming for the main wind strength and allowing the flex of the
masts depower for the gusts. The long  bows with low down bouyancy of
the lw hull allow a harry to use its righting moment. Offshore I may
be a bit more consevative and have a kite to send up to catch the
breeze. Theoretically you can work the kite to get more swept area
instead of tacking down wind. And if you had four crew you could take
it in turns to sip the iced tea --- In harryproa@...,
Mike Crawford <jmichael@g...> wrote:
>
>
>   I test sailed the R33, and it is indeed a very fast and boat.
With
> its tall mast and huge code 0 on the bowsprit, it's particularly
good in
> light air.  The design is a bit funky with that backrest, but it's
> really nice to lean back and sail when everything is set just
right.  It
> was an amazing value for $40,000 US (minus sails) when it was first
> advertised.  Now that it's closer to $140,000 US fully-rigged, it's
not
> quite such a value any more.
>
>   I chose a used Stiletto 27 instead of the Reynolds, partially
because
> it's nice to have a removable hard cockpit deck, and partially
because
> the entire boat could be had for the cost of a down payment on the
R33.
>
>   A Harry should be able to compete with an R33, but that would
require
> some effort.  You'd need either a really tall mast, a schooner rig,
> headsails, or a combination of the three.  The R33 would lack the
> Harry's righting moment, but it sure does have an awesome amount of
sail
> area for its weight.  Not quite like the Décision 35's, but still a
lot
> of canvas.
>
>   For the same price as an R33, you could have a really fast harry
that
> would include a head, galley, standing headroom, and two double
bunks.
> The Harry would also be a lot easier to sail, will probably be
safer,
> and should be faster in some wind conditions.  If you wanted to
race
> against the R33, though, you'd have to go past the standard easy
rig.
> It could be done, but you'd have to spend more time pulling strings
and
> less time sipping that ice cold drink.
>
>        - Mike
>
>
>
> Robert wrote:
>
> > Don't know about a Reynolds 33 at 'only 3000lbs' being necessarily
> > faster . A 40'lw hull harry weighs not much more than half of
that. You
> > can pile your stores in the ww hull to bring it to the same
weight and
> > you have 50% more righting moment and a longer waterline length
with
> > higher prismatic coefficient for the hull with the load on it so
you
> > can push it harder before pichpoling. This 3000lb is not much
less than
> > the 3700lbs for 50' Visionary, a cruiser built in strip plank.
> > Sometimes I wonder at the figures for Harry designs in contrast
with
> > catamarans and tris and try to work out where the differences are
but
> > there are now five built and the reality confirms the estimated
weights.
> > regards,
> > Robert
> >
> >
> >
> >
> > ------------------------------------------------------------------
------
> > *Yahoo! Groups Links*
> >
> >     * To visit your group on the web, go to:
> >       http://au.groups.yahoo.com/group/harryproa/
> >
> >     * To unsubscribe from this group, send an email to:
> >       harryproa-unsubscribe@...
> >       <mailto:harryproa-unsubscribe@...?
subject=Unsubscribe>
> >
> >     * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
> >       Service <http://au.docs.yahoo.com/info/terms/>.
> >
> >
>

"My objection wasn't with the Pacific proa. I have great fondness for
it after my time in PNG. I believe it has its place but not for long
haul cruising."

That is a fair point, but it falls into the same category as a cruise
ship passenger wondering why someone would cruise on any sailing
multihull.  Russ Brown doesn't recomend that you or I do it, you have
to want to do it for whatever wacky reason.


"My objection is the use of the lee pod as I believe
that it is an unseaworthy attachment. I can almost see some value in
it for flat seas as training wheels and as a lee platform for
drifting conditions but not once there is any swell. I can't see how
it can help prevent combination wind/wave capsize."

Right answer, wrong question.  It's not aobut capsize, but self-
righting, and it doesn't prevent knock down it just rights from it.

"On the side of a wave the boat would have to be about 90 degrees
before the leepod contributed to righting moment."

Right at the point where a PP without one might become stable in the
knock down position, it is doing it's work.  Somewhat similar to what
ballast does in the same situatiom.

"In breaking seas, if hit from the
side by a breaking wave it could dig in and flip the boat."

Not heard of that happening, doesn't seem to be a serious objection.
Reminds me of the Wharram/Boon drawing of a tri perched ona  rbeaking
wave about to get rolled over.  It might happen, but it either
doesn't or they have the sea anchor out, one hopes the literature is
not full of that kind of capsize.

There isn't much evidence of the pods digging in either, depends on
the exact shape, but generally they seem to rise out of a wave.


"It also
makes the boat less likely to be stabilised by mast bouyancy from
going over further."

Right, stabilizing with mast bouyancy is not what one wants in the
kind of situation that causes a capsize in the first place.  Self-
righting is the proven concept, or as with conventional cruising
multis a very high resistance to capsize.  Low resistance to capsize
combined with high stability in the capsized or KD position is not a
winner.

snip> There is the problems of surviving the 45kn of a thunderstorm.
Wind
> usually builds up to this speed from flat calm in 2-3 minutes, so you
> better take all sails down - fast! And ideally a seasoned crew should
> be able to keep the boat upright with a bare rig, for the 30-45min
> this lasts. But if the boat capsizes, then you can wait for some power
SOlved the problem. two 15m wings at 45 degrees to the boat and jeep on
all sails. four thunderstorms and you've finished the race.
Seriously, if you can get half the mast down and keep some sail up you
can cover a lot of ground.
  I can see a telescoping mast but i have difficulty with reliable
continuity of track. a sleeved sail is possible.
You could have a gunter type spar attached to an extra strong mast
track to extend the effective mast height by 4 or 5 metres.
regards,
Robert

Agreed. If I wanted to inshore race a harry I'd go for two tall
skinny  square topped sails with wingmasts and sail it like an
Elementarry, (Including the righting pole ;-)). I figure that if you
have the righting ability and the fore aft stability then you can
somehow get the extra sail area. Theoretically, a Harry loaded,
giving 50% more righting moment should allow a 20% higher rig and as
you are sailing upwind all the time, its the lengths of those luffs
that count. Or you can leave it light and have a similar height rig
trimming for the main wind strength and allowing the flex of the
masts depower for the gusts. The long  bows with low down bouyancy of
the lw hull allow a harry to use its righting moment. Offshore I may
be a bit more consevative and have a kite to send up to catch the
breeze. Theoretically you can work the kite to get more swept area
instead of tacking down wind. And if you had four crew you could take
it in turns to sip the iced tea --- In harryproa@...,
Mike Crawford <jmichael@g...> wrote:
>
>
>   I test sailed the R33, and it is indeed a very fast and boat.
With
> its tall mast and huge code 0 on the bowsprit, it's particularly
good in
> light air.  The design is a bit funky with that backrest, but it's
> really nice to lean back and sail when everything is set just
right.  It
> was an amazing value for $40,000 US (minus sails) when it was first
> advertised.  Now that it's closer to $140,000 US fully-rigged, it's
not
> quite such a value any more.
>
>   I chose a used Stiletto 27 instead of the Reynolds, partially
because
> it's nice to have a removable hard cockpit deck, and partially
because
> the entire boat could be had for the cost of a down payment on the
R33.
>
>   A Harry should be able to compete with an R33, but that would
require
> some effort.  You'd need either a really tall mast, a schooner rig,
> headsails, or a combination of the three.  The R33 would lack the
> Harry's righting moment, but it sure does have an awesome amount of
sail
> area for its weight.  Not quite like the Décision 35's, but still a
lot
> of canvas.
>
>   For the same price as an R33, you could have a really fast harry
that
> would include a head, galley, standing headroom, and two double
bunks.
> The Harry would also be a lot easier to sail, will probably be
safer,
> and should be faster in some wind conditions.  If you wanted to
race
> against the R33, though, you'd have to go past the standard easy
rig.
> It could be done, but you'd have to spend more time pulling strings
and
> less time sipping that ice cold drink.
>
>        - Mike
>
>
>
> Robert wrote:
>
> > Don't know about a Reynolds 33 at 'only 3000lbs' being necessarily
> > faster . A 40'lw hull harry weighs not much more than half of
that. You
> > can pile your stores in the ww hull to bring it to the same
weight and
> > you have 50% more righting moment and a longer waterline length
with
> > higher prismatic coefficient for the hull with the load on it so
you
> > can push it harder before pichpoling. This 3000lb is not much
less than
> > the 3700lbs for 50' Visionary, a cruiser built in strip plank.
> > Sometimes I wonder at the figures for Harry designs in contrast
with
> > catamarans and tris and try to work out where the differences are
but
> > there are now five built and the reality confirms the estimated
weights.
> > regards,
> > Robert
> >
> >
> >
> >
> > ------------------------------------------------------------------
------
> > *Yahoo! Groups Links*
> >
> >     * To visit your group on the web, go to:
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> >
> >     * To unsubscribe from this group, send an email to:
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subject=Unsubscribe>
> >
> >     * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
> >       Service <http://au.docs.yahoo.com/info/terms/>.
> >
> >
>

Rob, the 2006 Bol d'Or will be June 17-18.
Ready for 93 miles of lake racing?
I also do not think we'll have a chance against the M2s with the EL,
but hey, it will be fun. I only hope there will be more wind than in
2005. You're welcome to stay over at our place, naturally.

I agree about the importance of mast height, as limited as it is in
the M2 class to a meagre 16.6m ;-) Most racing boats here have mains
that are almost square. But nobody does it with unstayed una rigs,
because you absolutely need big reachers. A main only has not enough
sail area. And I do still believe, as most havigators here, in the
positive effect of a jib in front of the main.

I do not quite see how you can telescope a mast, even an unstayed one,
when sailing. Do you mean you do you do this at the harbour, or even
prior to assembling the boat? And how does the wing mast make this
easier vs. the round mast?

I am not sure the "extra height" is a problem in the breeze. IMHO once
you've taken a reef, the upper section adds some sail area high up,
but this is not so much of a problem.
There is the problems of surviving the 45kn of a thunderstorm. Wind
usually builds up to this speed from flat calm in 2-3 minutes, so you
better take all sails down - fast! And ideally a seasoned crew should
be able to keep the boat upright with a bare rig, for the 30-45min
this lasts. But if the boat capsizes, then you can wait for some power
boat to pull you upright (or gather the remains of the boat). On this
lake you're never more than 4nm offhore at its widest. In order not to
be washed ashore (which is mostly steep and rocky) you even ought to
capsize!

--- In harryproa@..., "Rob Denney" <proa@i...> wrote:
>
> G'day,
>
> When is the Bol d'Or this year?  Would be glad to sail it with you
of we can get the boat to and from Belgium to Switzerland.   Fun would
be no problem, beating the M2's may be.
>
> A una rigged El with carbon/nomex, pressure moulded everything looks
like it will be near enough 90 kgs.    An 8.5m would be less than 150%
of this
>
> For light air sailing mast height is everything (see Bethwaites
book) as wind strength increases rapidly with height.  Therefore the
highest mast possible would be the aim, rather than the largest sail
area.  The problem then becomes what to do with the extra height in a
breeze.  One possibility with a mast with no external fittings
(forestay, wishbone, etc) is a telescoping mast.  Doing this with a
round mast is pretty difficult, but with a wing mast  it would a lot
easier.  Would not be as quick as hoisting/dousing a headsail, but in
a race where it is either windy or not, it has some potential.
>
> regards,
>
> rob   ----- Original Message -----
>   From: dominiquebovey
>   To: harryproa@...
>   Sent: Thursday, January 26, 2006 1:24 PM
>   Subject: [harryproa] Re: 8.5m multi "box rule"
>
>
>   Rob,
>   I am DEFINITELY interested to sail the Elementarry, and yes you're
>   probably right, do the bol d'Or unofficially with a crew of two.
>   One one the goals is putting my company name on the sails o hulls, and
>   even unofficially it will get some media coverage... The main goal
>   being to have fun!
>   The 8.5m EL would be less than 200kg racing, the 8.5m cats weigh a
>   little less than 400kg, so EL needs about 2x less sail area for the
>   same sail/displ ratio, Hence the Melges sails. Also a way to limit
costs.
>   But it might be possible to find sails designed for the 8.5m, therefor
>   DOUBLING the ratio! Might be overkill, and difficult engineeringwise.
>
>   --- In harryproa@..., "Rob Denney" <proa@i...> wrote:
>   >
>   > G'day,
>   >
>   > Fixed length is not a proa strong point.  I am not sure whether the
>   weight and windage savings possible with a proa would offset that or
>   not.  It would certainly cost a lot less.  I would love to have a go
>   at designing something for it..   There are a few areas that proas can
>   exploit that are not open to cats.
>   >
>   > Maybe wait and see how the Elementarry being built in Belgium goes
>   against the Tornados (this summer, I hope)  and then look at what
>   should be scaled up and what can be reduced.  Incidentally, I will not
>   be competing in  the Bol d'Or (hope to be racing Blind Date in
>   Denmark), but the boat is available for charter if you or anyone is
>   interested.  I would advise that you do it unofficially with two crew,
>   rather than officially with three.
>   >
>   > Could you let us know the beam, mast height and sail area of the M2
>   class, please.  On the web page it looked like 70 sqm upwind, plus a
>   similar size screecher, but this does not tally with the Melges sails.
>   On this subject, I think the melges sails would be too light, and not
>   of optimum plan form for a light air boat which would have a near
>   rectangular main.
>   >
>   > regards,
>   >
>   > rob
>   >
>   >
>   >   Sorry for misquoting, David mentioned this box rule naturally.
>   >
>   >   Yes these crazy boats are incredible, I have seen them flying
a hull
>   >   on flat water, 8kn of speed with 5kn of wind. They work by
creating
>   >   their apparent wind. But their top speed is estimated at 30kn.
>   >
>   >   The last horrible wind-less Bol d'Or was done with "winds
averaging 3
>   >   knots", the winner took 18 hours for the 100 miles. That is
beyond my
>   >   nerves anyway.
>   >
>   >   There are two classes. the M1 (only Decision 35 today) are
machines
>   >   costing half a million swiss francs (about the same in AUD),
with a
>   >   racing budget of maybe half that on top of it every year. The
pre-preg
>   >   hull skin is less tha a millimeter thick...
>   >   And they are low cost machines versus the f40 they had before!
A very
>   >   well known owner of D35 is bertarelli, yes the poor guy who owns
>   >   alinghi and the america cup... Well I do not have any prospect of
>   >   competing (financially) for some time to come, even if I am a
rather
>   >   optimistic type.... But this might be a job for a Turbo-Harrigami.
>   >
>   >   But there is the M2 class, and the M2 are much more
"accessible" (for
>   >   a catamaran, around 100kCHF). The M2 are very close in
performance to
>   >   the M1, and I would be very happy to be in the 10 first of the Bol
>   >   d'Or to start...
>   >
>   >   A HarryM2 would probably cost much less than that (Rob, am I
right?),
>   >   because of the structural advantage, and would be competitive with
>   >   much less high tech gear than the cats and tris in this class. It
>   >   would be nice to be competitive with wood-epoxy hulls and
minimal use
>   >   of carbon (only rig and beams), against all-carbon-kevlar racing
>   >   machines. Kind of David against Goliath. But David still needs
a good
>   >   slingshot! And HarryM2 would still need a lot a sail.
>   >
>   >   To decrease cost while keeping good performance, I am
wondering if the
>   >   whole rig for an 8.5m can be built around "standard" sails. For
>   >   example, a melges 24 sail plan (24m2 main, 10m2 jib), of which you
>   >   find (not very much) used sails for reasonable prices, while only
>   >   needing to recut the jib a bit.
>   >
>   >   --- In harryproa@..., Mike Crawford <jmichael@g...>
>   wrote:
>   >   >
>   >   >
>   >   >   I think it was David Howie who wrote about the box rule, and
>   it just
>   >   > shows up in my posts because I keep on replying in the same
thread.
>   >   >
>   >   >   Any ideas David?
>   >   >
>   >   >   BTW, If I wanted to race on Lake Geneva, I'd be much more
>   likely to
>   >   > want something like those Décision 35's for which you provided a
>   >   link..
>   >   > That was you, Dominique, wasn't it?  In any case, I'm astounded
>   by the
>   >   > sail area carried by those boats, and am truly amazed with the
>   video
>   >   > that shows them flying hulls and sailing at speed without a
single
>   >   > whitecap to be seen.  I'd simply love to sail one for a few
days.
>   >   >
>   >   >   Those boats are way too finicky and fragile for something I'd
>   get,
>   >   > provided I could afford one in the first place, but there's no
>   denying
>   >   > that they are masterful speed machines, especially for light
air.
>   >   While
>   >   > I love the schooner rig with flexible unstayed masts, I'm
>   viewing this
>   >   > from the perspective of racing single-handed in gusty
>   conditions.  In a
>   >   > real race, in low wind, with crews that know what they are
>   doing, I'd
>   >   > have a hard time imagining anything beating  a Décision 35.
>   >   >
>   >   >   I don't truly want one of those fast cats for a variety of
>   reasons,
>   >   > but they sure do make me drool.  I'm going to go look at some
>   Décision
>   >   > 35 photos now, and maybe watch that video again.
>   >   >
>   >   >
>   >   >        - Mike
>   >   >
>   >   >
>   >   >
>   >   > dominiquebovey wrote:
>   >   >
>   >   > > Hi,
>   >   > > Mike just wrote about an 8.5m "box rule". On Lake Geneva,
>   switzerland,
>   >   > > there are two multihull classes, M1 (10.8m hull length,
>   >   > > Alinghi/Bertarelli is doing this) and M2 (8.5m), see this
link:
>   >   > > http://www.regates.ch/index.asp?ID=354.
>   >   > > My conceptions of rig stiffness are somehow influenced by
the sail
>   >   > > areas you see on the diagram... And lake geneva is terrible
>   for wind,
>   >   > > with most summer races in ghosting conditions (including
the "bold
>   >   > > d'or"), but in spring and fall there can be quite a lot of
wind.
>   >   > > What is the "box rule" you are talking about,Mike?
>   >   > >
>   >   > >
>   >   >
>   >
>   >
>   >
>   >
>   >
>   >
>   >
>
------------------------------------------------------------------------------
>   >   Yahoo! Groups Links
>   >
>   >     a.. To visit your group on the web, go to:
>   >     http://au.groups.yahoo.com/group/harryproa/
>   >
>   >     b.. To unsubscribe from this group, send an email to:
>   >     harryproa-unsubscribe@...
>   >
>   >     c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of
>   Service.
>   >
>
>
>
>
>
>
>
------------------------------------------------------------------------------
>   Yahoo! Groups Links
>
>     a.. To visit your group on the web, go to:
>     http://au.groups.yahoo.com/group/harryproa/
>
>     b.. To unsubscribe from this group, send an email to:
>     harryproa-unsubscribe@...
>
>     c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of
Service.
>

Don't know about a Reynolds 33 at 'only 3000lbs' being necessarily
faster . A 40'lw hull harry weighs not much more than half of that. You
can pile your stores in the ww hull to bring it to the same weight and
you have 50% more righting moment and a longer waterline length with
higher prismatic coefficient for the hull with the load on it so you
can push it harder before pichpoling. This 3000lb is not much less than
the 3700lbs for 50' Visionary, a cruiser built in strip plank. 
Sometimes I wonder at the figures for Harry designs in contrast with
catamarans and tris and try to work out where the differences are but
there are now five built and the reality confirms the estimated weights.
regards,
Robert

From: David Howie

To: harryproa@...

Sent: Sunday, January 29, 2006 8:11 AM

Subject: Re: [harryproa] Re: 8.5m multi

I like your stories about sailing the little one. First time I flipped the A
class I discovered I could not swim fast enough to catch it, second time over
I broke the tiller extension coz I refused to let go, now if I'm out by myself
(ie no rescue boat) I have a line around my waist and tied to the main beam.
Thanks again for all the help. I'll contact HM tues (anniversarty weekend
here) and see what they have to say. If I were to build all the smaller
components first at what point along the way would I have to make a commitment
on the rig, when building the lw hull?
------ Original Message ------
Received: Sat, 28 Jan 2006 04:27:42 PM MST
From: "Rob Denney" <proa@...>
To: <harryproa@...>
Subject: Re: [harryproa] Re: 8.5m multi

G'day,

High Mod are an excellent mob.    Mast options are to build your own using the
strip technique on http://www.harryproa.com/building_hg/buildinghg_wk14.htm
and http://www.harryproa.com/building_hg/buildinghg_wk15.htm or buy one from
us built using our new mouldless technique.  I cannot be specific on prices
until carbon tow becomes available again, unfortunately.  The self built mast
will obviously be cheaper, a little heavier, and more fun, depending on your
definition of fun!  Probably a thousand dollars difference between the two,
plus freight.

Re capsizing.  I have capsized Elementarry a few times.  The masts keep it on
it's side and also act as a sea anchor, so it blows round with the masts
pointing upwind.  This happens very quickly, usually before I have finished
swearing.  I then right it by deploying and standing on a 3m long piece of 4 x
2 timber, tied to the windward hull and braced against the lee end of one of
the beams.  Bit of a balancing act to get out there, but it comes up pretty
easily, and rounds up head to wind in the process.  A kite would be a fun
option on the bigger boats, but I suspect a big canvas bag of water and a
block and tackle would be easier to use.  The windage of the trampoline and
cabins are helpful once it has blown round masthead to windward, but it sure
blows sideways fast.  In 20 knots, I can barely keep up swimming flat out.

regards,

rob----- Original Message -----
  From: David Howie
  To: harryproa@...
  Sent: Sunday, January 29, 2006 7:10 AM
  Subject: Re: [harryproa] Re: 8.5m multi


  Thanks, I was going to try High Modulus ( the boss lives just over the hill
  from here), on the materials list for harrigami which I',m using as a guide
  for harry you simply give a price for a prof. made spar and suggest a new
  system that will reduce the figure significantly. I'm assuming that since
that
  was written the new system is up and running, care to comment on relative
  price now it's been done.

  ------ Original Message ------
  Received: Sat, 28 Jan 2006 12:02:16 AM MST
  From: "Rob Denney" <proa@...>
  To: <harryproa@...>
  Subject: Re: [harryproa] Re: 8.5m multi

  G'day,

  The thicker the tow, the lower the cost.  200 gsm carbon cloth is made from
3k
  tow k stands for thousand, 3k is 3,000 filaments per tow.  We use 48, 50 or
80
  and I am trying to get some 160k.  T300 or equivalent is the grade you want.

  Otherwise known as standard modulus.

  There is a world wide shortage of carbon at the moment, probably till the
end
  of this year, when with new plants coming on line, there may be a glut.
The
  price is high at the moment,. will reduce when the new plant come on line,
  regardless of a glut or not. 

  We were paying $US7.70 per pound, ex Texas a year or so ago.  Finding it
very
  hard to get any at all at the moment.  When we do get some, it will be a
big
  order.  You are welcome to include your order in ours and receive our price.



  regards,

  rob
    ----- Original Message -----
    From: David Howie
    To: harryproa@...
    Sent: Friday, January 27, 2006 9:40 AM
    Subject: Re: [harryproa] Re: 8.5m multi


    I'm going over the material list trying to get prices here, can you tell
me
  what I should be asking for regards the carbon tow, seems it comes in a
  variety of shapes and sizes.

    Thanks


    ------ Original Message ------
    Received: Thu, 26 Jan 2006 03:30:13 AM MST
    From: "Rob Denney" <proa@...>
    To: <harryproa@...>
    Subject: Re: [harryproa] Re: 8.5m multi "box rule"




    G'day,

    When is the Bol d'Or this year?  Would be glad to sail it with you of we
can
  get the boat to and from Belgium to Switzerland.   Fun would be no problem,
  beating the M2's may be.

    A una rigged El with carbon/nomex, pressure moulded everything looks like
it
  will be near enough 90 kgs.    An 8.5m would be less than 150% of this

    For light air sailing mast height is everything (see Bethwaites book) as
  wind strength increases rapidly with height.  Therefore the highest mast
  possible would be the aim, rather than the largest sail area.  The problem
  then becomes what to do with the extra height in a breeze.  One possibility
  with a mast with no external fittings (forestay, wishbone, etc) is a
  telescoping mast.  Doing this with a round mast is pretty difficult, but
with
  a wing mast  it would a lot easier.  Would not be as quick as
hoisting/dousing
  a headsail, but in a race where it is either windy or not, it has some
  potential. 

    regards,

    rob   ----- Original Message -----
      From: dominiquebovey
      To: harryproa@...
      Sent: Thursday, January 26, 2006 1:24 PM
      Subject: [harryproa] Re: 8.5m multi "box rule"


      Rob,
      I am DEFINITELY interested to sail the Elementarry, and yes you're
      probably right, do the bol d'Or unofficially with a crew of two.
      One one the goals is putting my company name on the sails o hulls, and
      even unofficially it will get some media coverage... The main goal
      being to have fun!
      The 8.5m EL would be less than 200kg racing, the 8.5m cats weigh a
      little less than 400kg, so EL needs about 2x less sail area for the
      same sail/displ ratio, Hence the Melges sails. Also a way to limit
costs.

      But it might be possible to find sails designed for the 8.5m, therefor
      DOUBLING the ratio! Might be overkill, and difficult engineeringwise.

      --- In harryproa@..., "Rob Denney" <proa@i...> wrote:
      >
      > G'day,
      >
      > Fixed length is not a proa strong point.  I am not sure whether the
      weight and windage savings possible with a proa would offset that or
      not.  It would certainly cost a lot less.  I would love to have a go
      at designing something for it..   There are a few areas that proas can
      exploit that are not open to cats.  
      >
      > Maybe wait and see how the Elementarry being built in Belgium goes
      against the Tornados (this summer, I hope)  and then look at what
      should be scaled up and what can be reduced.  Incidentally, I will not
      be competing in  the Bol d'Or (hope to be racing Blind Date in
      Denmark), but the boat is available for charter if you or anyone is
      interested.  I would advise that you do it unofficially with two crew,
      rather than officially with three. 
      >
      > Could you let us know the beam, mast height and sail area of the M2
      class, please.  On the web page it looked like 70 sqm upwind, plus a
      similar size screecher, but this does not tally with the Melges sails.
      On this subject, I think the melges sails would be too light, and not
      of optimum plan form for a light air boat which would have a near
      rectangular main. 
      >
      > regards,
      >
      > rob
      >
      >
      >   Sorry for misquoting, David mentioned this box rule naturally.
      >
      >   Yes these crazy boats are incredible, I have seen them flying a
hull
      >   on flat water, 8kn of speed with 5kn of wind. They work by creating
      >   their apparent wind. But their top speed is estimated at 30kn.
      >
      >   The last horrible wind-less Bol d'Or was done with "winds averaging
3
      >   knots", the winner took 18 hours for the 100 miles. That is beyond
my
      >   nerves anyway.
      >
      >   There are two classes. the M1 (only Decision 35 today) are machines
      >   costing half a million swiss francs (about the same in AUD), with a
      >   racing budget of maybe half that on top of it every year. The
  pre-preg
      >   hull skin is less tha a millimeter thick...
      >   And they are low cost machines versus the f40 they had before! A
very
      >   well known owner of D35 is bertarelli, yes the poor guy who owns
      >   alinghi and the america cup... Well I do not have any prospect of
      >   competing (financially) for some time to come, even if I am a
rather
      >   optimistic type.... But this might be a job for a Turbo-Harrigami.
      >
      >   But there is the M2 class, and the M2 are much more "accessible"
(for
      >   a catamaran, around 100kCHF). The M2 are very close in performance
to
      >   the M1, and I would be very happy to be in the 10 first of the Bol
      >   d'Or to start...
      >
      >   A HarryM2 would probably cost much less than that (Rob, am I
right?),
      >   because of the structural advantage, and would be competitive with
      >   much less high tech gear than the cats and tris in this class. It
      >   would be nice to be competitive with wood-epoxy hulls and minimal
use
      >   of carbon (only rig and beams), against all-carbon-kevlar racing
      >   machines. Kind of David against Goliath. But David still needs a
good

      >   slingshot! And HarryM2 would still need a lot a sail.
      >
      >   To decrease cost while keeping good performance, I am wondering if
  the
      >   whole rig for an 8.5m can be built around "standard" sails. For
      >   example, a melges 24 sail plan (24m2 main, 10m2 jib), of which you
      >   find (not very much) used sails for reasonable prices, while only
      >   needing to recut the jib a bit.
      >
      >   --- In harryproa@..., Mike Crawford <jmichael@g...>
      wrote:
      >   >
      >   >
      >   >   I think it was David Howie who wrote about the box rule, and
      it just
      >   > shows up in my posts because I keep on replying in the same
thread.

      >   >
      >   >   Any ideas David?
      >   >
      >   >   BTW, If I wanted to race on Lake Geneva, I'd be much more
      likely to
      >   > want something like those Décision 35's for which you provided a
      >   link.. 
      >   > That was you, Dominique, wasn't it?  In any case, I'm astounded
      by the
      >   > sail area carried by those boats, and am truly amazed with the
      video
      >   > that shows them flying hulls and sailing at speed without a single

      >   > whitecap to be seen.  I'd simply love to sail one for a few days.

      >   >
      >   >   Those boats are way too finicky and fragile for something I'd
      get,
      >   > provided I could afford one in the first place, but there's no
      denying
      >   > that they are masterful speed machines, especially for light air.

      >   While
      >   > I love the schooner rig with flexible unstayed masts, I'm
      viewing this
      >   > from the perspective of racing single-handed in gusty
      conditions.  In a
      >   > real race, in low wind, with crews that know what they are
      doing, I'd
      >   > have a hard time imagining anything beating  a Décision 35.
      >   >
      >   >   I don't truly want one of those fast cats for a variety of
      reasons,
      >   > but they sure do make me drool.  I'm going to go look at some
      Décision
      >   > 35 photos now, and maybe watch that video again.
      >   >
      >   >
      >   >        - Mike
      >   >
      >   >
      >   >
      >   > dominiquebovey wrote:
      >   >
      >   > > Hi,
      >   > > Mike just wrote about an 8.5m "box rule". On Lake Geneva,
      switzerland,
      >   > > there are two multihull classes, M1 (10.8m hull length,
      >   > > Alinghi/Bertarelli is doing this) and M2 (8.5m), see this link:
      >   > > http://www.regates.ch/index.asp?ID=354.
      >   > > My conceptions of rig stiffness are somehow influenced by the
  sail
      >   > > areas you see on the diagram... And lake geneva is terrible
      for wind,
      >   > > with most summer races in ghosting conditions (including the
  "bold
      >   > > d'or"), but in spring and fall there can be quite a lot of
wind.
      >   > > What is the "box rule" you are talking about,Mike?
      >   > >
      >   > >
      >   >
      >
      >
      >
      >
      >
      >
      >
    

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Don't know about a Reynolds 33 at 'only 3000lbs' being necessarily
faster . A 40'lw hull harry weighs not much more than half of that. You
can pile your stores in the ww hull to bring it to the same weight and
you have 50% more righting moment and a longer waterline length with
higher prismatic coefficient for the hull with the load on it so you
can push it harder before pichpoling. This 3000lb is not much less than
the 3700lbs for 50' Visionary, a cruiser built in strip plank.
Sometimes I wonder at the figures for Harry designs in contrast with
catamarans and tris and try to work out where the differences are but
there are now five built and the reality confirms the estimated weights.
regards,
Robert

Glad thats sorted, hope I didn't appear too brash. I frequently
appear arrogant in my statements but need feedback to refine my ideas
and I have been known to talk crap and sometimes have niggling doubts
that I may be. This feedback is an important part of this forum for
me,
Thanks
robert
  --- In harryproa@..., Mike Crawford <jmichael@g...>
wrote:
>
> << In general we don't have a great deal of disagreement >>
>
>   Agreed.
>
>   I just misunderstood what you meant by the leeward pod in the
initial
> posting.  I'm so used to people on other forums getting religious
about
> Pacific versus Atlantic that I ended to going overboard in the
> explanation.  Oh well.  Better than than flaming you...
>
>   I do think the leeward pod on a design like Jzerro could be an
asset
> if you like to keep the boat on the edge, and are quick enough to
dump
> the sheets once that pod does start to dig in.  It could buy you a
few
> extra seconds if an unexpected gust comes by.  However, this only
goes
> for when you're out having fun daysailing.  As you point out, the
pod
> could be a liability once you get into real weather.
>
>   I think your comment about the leeward pod diminishing the effect
of
> mast buoyancy in a capsize is particularly salient given the
current
> self-righting discussion.
>
>        - Mike
>
>
> Robert wrote:
>
> > --- In harryproa@..., Mike Crawford <jmichael@g...>
> > wrote:
> > >
> > >
> > > Robert wrote:
> > >
> > > > I am not quite sure if I am on the same planet as those who
> > persist
> > > > in a lw pod for a sailing proa. Am I missing somethingin my
> > > > understanding of hydrodynamics and hydrostatics. My
calculatons
> > for
> > > > the hydrostaics show the boat has a greater tendancy to keep
going
> > > > over if slightly >90degrees as the ww hull is more likely to
go
> > paast
> > > > top dead centre.
> > >
> > >
> > >   I think some of the pacific proa designs can be amazingly
> > efficient
> > > when given just the right conditions, which is probably why some
> > favor
> > > them.
> > In general we don't have a great deal of disagreement
> > I agree about the pacific proa. For example Elementarry. Though
> > Elementarry may be even faster though not as easy to sail in
Atlantic
> > mode. keeping the lee hull just out of the water in low winds and
> > more righting moment with the ww hull just skimmming the water in
> > higher winds. Would not be easy but theoretically faster. I have
> > sketches for a monocoque proa with a fold out cockpit based on an
> > elementarry that I reckon would be a little bit better as an
Atlantic
> > schooner
> >
> > >
> > >   With more weight in the large leeward hull, you can
theoretically
> > cut
> > > down on hydrodynamic drag.  Check out the comparison chart
halfway
> > down
> > > the page on
> > >
http://proafile.com/view/weblog/comments/cheap_capable_cruisers_iii/
> > >
> > >   If you can get the weight in the long hull, and then either
> > lighten
> > > the windward hull, fly the windward hull, or use it as a vector
> > fin, you
> > > can probably get more speed for less sail area.  I've not taken
> > fluid
> > > mechanics, but I'll buy the argument.
> >
> > I have actually taken fluid dynamics. I am suspending judgement on
> > the vector fin and generally agree that if you keep the weight on
one
> > hull then you lessen drag. You can lessen drag at low speeds even
> > more by going to a fat mono. But you also need righting moment to
> > generate power. Probably this can be done with a vector fin but it
> > seems much more reliable to  use weight not needed in the lw
hull. If
> > the vector fin works as claimed , then it is contributing to extra
> > downward force overall on the boat,ie  equivalent to extra overall
> > weight similar to water ballast. Jzerro used water ballast to get
the
> > righting moment and needed more sail area than equivalent length
harry
> > This doesn't tally with less weight less drag less sail area.
> > I spent a few years in PNG and had experience with some of their
40'
> > racing canoes. They had plenty of crew constantly racing backwards
> > and forwards keeping the canoe balanced but once a bit of wind
came
> > up they were all, but the steersman, on the outrigger. This is in
> > steady trade wind conditions.
> > If you are going to rely on moving human ballast around constantly
> > then a Pacific proa works very nicely and using semistayed masts
is
> > probably the lightest engineering. With the use of unstayed msats
I
> > calculate things  change to an Atlantic rig. For a long term
offshore
> > boat you don't want to be living on the edge constantly so for
safety
> > considerations you put all the necessary weight that you can in
the
> > ww hull as permanent righting moment- within reason- you need some
> > weight in lw hull. The Atlantic rig has the problem of interfering
> > with accommodation and sheeting arrangements that make it
difficult
> > for weather cocking. The amount of weight in the rig seems a good
> > compromise for the lw hull and bouyant masts can help prevent
> > complete overturning if someone is mug enough to leave the sheets
> > cleated with ridiculous amounts of sail in lumpy seas.
> >
> > My objection wasn't with the Pacific proa. I have great fondness
for
> > it after my time in PNG. I believe it has its place but not for
long
> > haul cruising. My objection is the use of the lee pod as I believe
> > that it is an unseaworthy attachment. I can almost see some value
in
> > it for flat seas as training wheels and as a lee platform for
> > drifting conditions but not once there is any swell. I can't see
how
> > it can help prevent combination wind/wave capsize. On the side of
a
> > wave the boat would have to be about 90 degrees before the leepod
> > contributed to righting moment. In breaking seas, if hit from the
> > side by a breaking wave it could dig in and flip the boat. It also
> > makes the boat less likely to be stabilised by mast bouyancy from
> > going over further.
> > Rob has iterated most of these point many times. This is based on
> > his undertanding of the engineering and many years experience in
all
> > sorts of sailing craft in all sorts of conditions. My experience
of
> > the sea as a professional fisherman working in Bass Strait and
many
> > years of surfing various craft, coupled with a degree in
mathematics
> > fully support his reasoning.
> >
> >
> >   This would be why Jzerro can do
> > > 20 knots without a whole lot of righting moment.  It's kind of
an
> > > evolution of the proa mantra: less weight, less drag, less sail
> > area,
> > > and yet more speed.
> > >
> > >   This really comes true in the vector fin proa that is shown at
> > > http://www.proadesign.com/ .  I'm sure that thing is wicked fast
> > given
> > > the right conditions.  The designer even claims it will hang on
the
> > edge
> > > of a vertical wave face, which might even be true if you're
moving
> > the
> > > right way.  This might be true, but since he won't let anyone
sail
> > with
> > > him, or race against him, it's tough to tell.
> > >
> > >   However, we don't always sail in just the right conditions.
As
> > Rob
> > > has pointed out, if that windward vector fin were to come out of
> > the
> > > water, or get fouled with a plastic bag or seaweed, you could
be in
> > a
> > > world of trouble.  Likewise, if you were to get a solid gust
when
> > fying
> > > a hull on Jzerro, there wouldn't be much to stop you from going
> > over.
> > > The leeward pod overhang would help, but I'm not sure I'd want
to
> > try it.
> > >
> > >   The Harry proa might have more drag than a traditional pacific
> > proa,
> > > but there's more to a fast boat than drag.  A greater righting
> > moment
> > > means more sail area, and more lift, and that can mean a lot.
Then
> > > Imagine what you can do when skimming or flying the ww hull of a
> > harry!
> > >
> > >    It's also nice to have a greater righting moment if you're
> > heading
> > > windward in big weather, or trying to ride out a storm.  With
> > rudders up
> > > and sails or bare poles to leeward, the harryproa will tend to
> > itself
> > > quite nicely.
> > >
> > >   The "dutch proa" at http://www.bijlard.demon.nl/ is pretty
> > > interesting.  That additional leeward pod/ama would certainly
help,
> > and
> > > would be a great point of balance where you could fly a hull,
and
> > then
> > > adjust sheet loads to keep both amas out of the water without
> > worrying
> > > about imminent capsize.  As some have noted, though, it's
really a
> > > stunted trimaran, and the extra weight would be better used for
> > righting
> > > moment.
> > >
> > >   In the end, the harryproa seems to be the best approach to a
> > series of
> > > conflicting design goals (including speed vs. safety), and as
side
> > > benefits, it also manages to keep masts and daggerboards out of
the
> > hull
> > > with the accommodations, and it can even be tacked or backwinded
> > without
> > > major issues.
> > >
> > >   However, i can see why the purists out there like the less-is-
> > more
> > > solution of the pod in the leeward hull.
> > >
> > >        - Mike
> > >
> >
> >
> >
> >
> >
> >
> > ------------------------------------------------------------------
------
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> >
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> >       Service <http://au.docs.yahoo.com/info/terms/>.
> >
> >
>

I agree that to go right over on a decent size cruising multihull it
will be becuase of waves. In those circumstances the rig may not
survive, but if it did then certainly a bit of post capsize added
bouyancy to the mast head would get you a fair way up but may need a
bit of extra support for loading on the tip like that. For racing off
shore when you are pushing things to the edge a much more likely
scenario is like an Elementarry capsize. This kite exercise is more
to answer those people who say you can't get a harry back over if it
inverts. More of an ego thing saying can to their can't but also to
give comfort to those who would like to sail with you but have had
their heads filled with monomaniac chestnuts  about how much more
unsafe multihulls are because they can't get back over if inverted.
Statistics don't seem to help that much.
   If half over and supported by the masts, a gantry and seabucket as
Rob says , is much more controllable. Part of why I like the kite
idea is that you get the wind to do the work for you and you are
lifting the hull more than dragging and less likely to cause further
damage. It would be a pretty scary (fun?) exercise.
regards
Robert -
-- In harryproa@..., David Howie <dana-tenacity@u...>
wrote:
>
> Guess you could attach an iflatable dinghy to a halyard and send it
up/along
> the mast top hold horizontal till you sorted the kite thing.
> IMHO people spend way too much time obssessing over the capsize
thing, in
> larger than beach type multis it's not really that likely,
certainly not from
> wind pressure under normal sailing conditions. If you are offshore
in serious
> shit the waves will be what get ya.
> Still it's interesting to follow all the suggestions, and it would
definitely
> be great if you could right the boat unaided if the worst were to
happen, and
> the kite with harry on it's side seems as promising as any.
> BTW thought that Reynolds 33 someone sent us to was a cool boat
too, think it
> would beat harry for speed but not accomodation or price.
>
> ------ Original Message ------
> Received: Sat, 28 Jan 2006 01:39:58 PM MST
> From: Mike Crawford <jmichael@g...>
> To: harryproa@...
> Subject: Re: [harryproa] kite traction
>
> <<wouldn't an airtight/watertight spar be enough to keep from
turtling?>>
>
>   One would hope.  ;-)
>
>   Rob once hinted at this in an article a few years back, but I
haven't
> seen anything since then.  Perhaps someone has done some
calculations
> along the way.  Once the boat is at 90-100 degrees, there won't be
much
> heeling moment from the windward hull, but the sail area of the
deck
> could be an issue, especially if a lot of it is close-weaved mesh
or a
> solid surface.
>
>   Perhaps a wing-masted schooner rig might have enough buoyancy.
You'd
> still have to figure out how to run halyards, though.  Maybe in a
> separate sleeve/section?
>
>   Even if the boat does want to keep rotating to turtle, the area
of the
> sails and the buoyancy of the sealed masts should still give you
enough
> time to deploy an inflatable righting system.  If you're still in
the
> boat, of course.
>
>        - Mike
>
>
>
> David Howie wrote:
>
> > Wouldn't an airtight/watertight spar be enough to keep from
turtling?
> >
> > ------ Original Message ------
> > Received: Sat, 28 Jan 2006 09:53:45 AM MST
> > From: Mike Crawford <jmichael@g...>
> > To: harryproa@...
> > Subject: Re: [harryproa] kite traction
> >
> >
> >   That's one of the more unique ideas I've heard.
> >
> >   Randy Reynolds claims to be perfecting his system for righting
the R33
> > cats when they go over, and says he has tested the system four
times.
> > Many people are waiting for the official unveiling.  It's briefly
> > described towards the bottom of
http://www.r33.com/en/update/index.asp .
> >
> >   The Firebird catamaran folks sell a compressed gas righting
system for
> > their 26' catamaran for $4,000, shown on their options page at
> >
http://www.firebirdcat.com/pricing_and_options.htm/pricing_options.htm
  .
> >
> >   I'm waiting to see what Randy claims is so wonderful before
getting
> > serious about a choice, either for a proa or for the current boat.
> >
> >   As for the kites, they are one of the few ways I can think of
to right
> > a boat on on your own.  If you can set up a compressed gas
righting
> > system to keep the boat from going turtle, then you won't need a
large
> > kite at all.  If the boat is all the way over, you'll need a lot
more
> > lift.
> >
> >   You could conceivably strap a carbon spar underneath the deck,
erect
> > it once the boat has turned turtle, stay it to the leeward hull,
and fly
> > either an outleader or a water-relaunchable traction kite from
it.  I'd
> > want the spar for two reasons:
> >
> >     - Outleaders won't likely want to launch, or relaunch,
especially
> > when wet, without something that will lift them off the
deck/water.
> >
> >     - Any kite powerful enough to generate 400Kg of lift will
likely be
> > too dangerous to handle.  I've spent years traction kiting on
land, and
> > shudder to think about controlling that kind of force.  It will
be safer
> > to use a much smaller kite, with a more horizontal force, and use
the
> > righting moment of a spar to your advantage.
> >
> >   The outleader would certainly make sense if you already have it
on
> > board.   Of course, then you might have to swim to get it.  I'd
probably
> > have an emergency bag strapped or built into the underside of the
deck,
> > or along one of the beams, with the necessary kite, lines, cell
phone,
> > handheld vhf, flares, and so forth.  This is what I'm working on
for the
> > current catamaran, minus the traction kite, just in case.
> >
> >   You might need that spar for righting in any event, even with a
> > support boat.  A number of racing and pocket cruising cats can be
> > somewhat easily righted by reverse pitchpoling them, but i don't
believe
> > that a proa will lend itself to going end-over-end.
> >
> >   Everything would be easier if there were some sort of inflatable
> > righting system to prevent the boat from going all the way over.
Plus,
> > even if the boat were to turtle, flotation would still make
righting it
> > easier.
> >
> >        - Mike
> >
> >
> > Robert wrote:
> >
> > > Looking at the kite boarders I started to think about how much
traction
> > > a kite has. It would not take a very large kite to lift the lw
hull out
> > > of the water and back over where it belongs if you were unlucky
to be
> > > flipped by a wave. For a Harry 12m lw hull it weighs less than
350kg. A
> > > couple of powerfoils can generate that much lift, so surely an
> > > outleader kite should be able to drag the lw hull up and over.
> > > Is my arithmetic correct. I am not sure how easy it would be to
turn
> > > the boat upside down to try it but It would be an ineresting
exercise.
> > > It might need a little mast head bouyancy added using the
halliards in
> > > light airs. The concept could be tried out with a beach cat and
a kite
> > > from a kite board.
> > > Regards,
> > > Robert
> > >
> > >
> > >
> > >
> > >
> > > ----------------------------------------------------------------
--------
> > > *Yahoo! Groups Links*
> > >
> > >     * To visit your group on the web, go to:
> > >       http://au.groups.yahoo.com/group/harryproa/
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> > >       harryproa-unsubscribe@...
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subject=Unsubscribe>
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> >
> >
> >
> >
> >
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>

I like your stories about sailing the little one. First time I flipped the A
class I discovered I could not swim fast enough to catch it, second time over
I broke the tiller extension coz I refused to let go, now if I'm out by myself
(ie no rescue boat) I have a line around my waist and tied to the main beam.
Thanks again for all the help. I'll contact HM tues (anniversarty weekend
here) and see what they have to say. If I were to build all the smaller
components first at what point along the way would I have to make a commitment
on the rig, when building the lw hull?
------ Original Message ------
Received: Sat, 28 Jan 2006 04:27:42 PM MST
From: "Rob Denney" <proa@...>
To: <harryproa@...>
Subject: Re: [harryproa] Re: 8.5m multi

G'day,

High Mod are an excellent mob.    Mast options are to build your own using the
strip technique on http://www.harryproa.com/building_hg/buildinghg_wk14.htm
and http://www.harryproa.com/building_hg/buildinghg_wk15.htm or buy one from
us built using our new mouldless technique.  I cannot be specific on prices
until carbon tow becomes available again, unfortunately.  The self built mast
will obviously be cheaper, a little heavier, and more fun, depending on your
definition of fun!  Probably a thousand dollars difference between the two,
plus freight.

Re capsizing.  I have capsized Elementarry a few times.  The masts keep it on
it's side and also act as a sea anchor, so it blows round with the masts
pointing upwind.  This happens very quickly, usually before I have finished
swearing.  I then right it by deploying and standing on a 3m long piece of 4 x
2 timber, tied to the windward hull and braced against the lee end of one of
the beams.  Bit of a balancing act to get out there, but it comes up pretty
easily, and rounds up head to wind in the process.  A kite would be a fun
option on the bigger boats, but I suspect a big canvas bag of water and a
block and tackle would be easier to use.  The windage of the trampoline and
cabins are helpful once it has blown round masthead to windward, but it sure
blows sideways fast.  In 20 knots, I can barely keep up swimming flat out.

regards,

rob----- Original Message -----
   From: David Howie
   To: harryproa@...
   Sent: Sunday, January 29, 2006 7:10 AM
   Subject: Re: [harryproa] Re: 8.5m multi


   Thanks, I was going to try High Modulus ( the boss lives just over the hill
   from here), on the materials list for harrigami which I',m using as a guide
   for harry you simply give a price for a prof. made spar and suggest a new
   system that will reduce the figure significantly. I'm assuming that since
that
   was written the new system is up and running, care to comment on relative
   price now it's been done.

   ------ Original Message ------
   Received: Sat, 28 Jan 2006 12:02:16 AM MST
   From: "Rob Denney" <proa@...>
   To: <harryproa@...>
   Subject: Re: [harryproa] Re: 8.5m multi

   G'day,

   The thicker the tow, the lower the cost.  200 gsm carbon cloth is made from
3k
   tow k stands for thousand, 3k is 3,000 filaments per tow.  We use 48, 50 or
80
   and I am trying to get some 160k.  T300 or equivalent is the grade you want.

   Otherwise known as standard modulus.

   There is a world wide shortage of carbon at the moment, probably till the
end
   of this year, when with new plants coming on line, there may be a glut.
The
   price is high at the moment,. will reduce when the new plant come on line,
   regardless of a glut or not.

   We were paying $US7.70 per pound, ex Texas a year or so ago.  Finding it
very
   hard to get any at all at the moment.  When we do get some, it will be a
big
   order.  You are welcome to include your order in ours and receive our price.



   regards,

   rob
     ----- Original Message -----
     From: David Howie
     To: harryproa@...
     Sent: Friday, January 27, 2006 9:40 AM
     Subject: Re: [harryproa] Re: 8.5m multi


     I'm going over the material list trying to get prices here, can you tell
me
   what I should be asking for regards the carbon tow, seems it comes in a
   variety of shapes and sizes.

     Thanks


     ------ Original Message ------
     Received: Thu, 26 Jan 2006 03:30:13 AM MST
     From: "Rob Denney" <proa@...>
     To: <harryproa@...>
     Subject: Re: [harryproa] Re: 8.5m multi "box rule"




     G'day,

     When is the Bol d'Or this year?  Would be glad to sail it with you of we
can
   get the boat to and from Belgium to Switzerland.   Fun would be no problem,
   beating the M2's may be.

     A una rigged El with carbon/nomex, pressure moulded everything looks like
it
   will be near enough 90 kgs.    An 8.5m would be less than 150% of this

     For light air sailing mast height is everything (see Bethwaites book) as
   wind strength increases rapidly with height.  Therefore the highest mast
   possible would be the aim, rather than the largest sail area.  The problem
   then becomes what to do with the extra height in a breeze.  One possibility
   with a mast with no external fittings (forestay, wishbone, etc) is a
   telescoping mast.  Doing this with a round mast is pretty difficult, but
with
   a wing mast  it would a lot easier.  Would not be as quick as
hoisting/dousing
   a headsail, but in a race where it is either windy or not, it has some
   potential.

     regards,

     rob   ----- Original Message -----
       From: dominiquebovey
       To: harryproa@...
       Sent: Thursday, January 26, 2006 1:24 PM
       Subject: [harryproa] Re: 8.5m multi "box rule"


       Rob,
       I am DEFINITELY interested to sail the Elementarry, and yes you're
       probably right, do the bol d'Or unofficially with a crew of two.
       One one the goals is putting my company name on the sails o hulls, and
       even unofficially it will get some media coverage... The main goal
       being to have fun!
       The 8.5m EL would be less than 200kg racing, the 8.5m cats weigh a
       little less than 400kg, so EL needs about 2x less sail area for the
       same sail/displ ratio, Hence the Melges sails. Also a way to limit
costs.

       But it might be possible to find sails designed for the 8.5m, therefor
       DOUBLING the ratio! Might be overkill, and difficult engineeringwise.

       --- In harryproa@..., "Rob Denney" <proa@i...> wrote:
       >
       > G'day,
       >
       > Fixed length is not a proa strong point.  I am not sure whether the
       weight and windage savings possible with a proa would offset that or
       not.  It would certainly cost a lot less.  I would love to have a go
       at designing something for it..   There are a few areas that proas can
       exploit that are not open to cats.
       >
       > Maybe wait and see how the Elementarry being built in Belgium goes
       against the Tornados (this summer, I hope)  and then look at what
       should be scaled up and what can be reduced.  Incidentally, I will not
       be competing in  the Bol d'Or (hope to be racing Blind Date in
       Denmark), but the boat is available for charter if you or anyone is
       interested.  I would advise that you do it unofficially with two crew,
       rather than officially with three.
       >
       > Could you let us know the beam, mast height and sail area of the M2
       class, please.  On the web page it looked like 70 sqm upwind, plus a
       similar size screecher, but this does not tally with the Melges sails.
       On this subject, I think the melges sails would be too light, and not
       of optimum plan form for a light air boat which would have a near
       rectangular main.
       >
       > regards,
       >
       > rob
       >
       >
       >   Sorry for misquoting, David mentioned this box rule naturally.
       >
       >   Yes these crazy boats are incredible, I have seen them flying a
hull
       >   on flat water, 8kn of speed with 5kn of wind. They work by creating
       >   their apparent wind. But their top speed is estimated at 30kn.
       >
       >   The last horrible wind-less Bol d'Or was done with "winds averaging
3
       >   knots", the winner took 18 hours for the 100 miles. That is beyond
my
       >   nerves anyway.
       >
       >   There are two classes. the M1 (only Decision 35 today) are machines
       >   costing half a million swiss francs (about the same in AUD), with a
       >   racing budget of maybe half that on top of it every year. The
   pre-preg
       >   hull skin is less tha a millimeter thick...
       >   And they are low cost machines versus the f40 they had before! A
very
       >   well known owner of D35 is bertarelli, yes the poor guy who owns
       >   alinghi and the america cup... Well I do not have any prospect of
       >   competing (financially) for some time to come, even if I am a
rather
       >   optimistic type.... But this might be a job for a Turbo-Harrigami.
       >
       >   But there is the M2 class, and the M2 are much more "accessible"
(for
       >   a catamaran, around 100kCHF). The M2 are very close in performance
to
       >   the M1, and I would be very happy to be in the 10 first of the Bol
       >   d'Or to start...
       >
       >   A HarryM2 would probably cost much less than that (Rob, am I
right?),
       >   because of the structural advantage, and would be competitive with
       >   much less high tech gear than the cats and tris in this class. It
       >   would be nice to be competitive with wood-epoxy hulls and minimal
use
       >   of carbon (only rig and beams), against all-carbon-kevlar racing
       >   machines. Kind of David against Goliath. But David still needs a
good

       >   slingshot! And HarryM2 would still need a lot a sail.
       >
       >   To decrease cost while keeping good performance, I am wondering if
   the
       >   whole rig for an 8.5m can be built around "standard" sails. For
       >   example, a melges 24 sail plan (24m2 main, 10m2 jib), of which you
       >   find (not very much) used sails for reasonable prices, while only
       >   needing to recut the jib a bit.
       >
       >   --- In harryproa@..., Mike Crawford <jmichael@g...>
       wrote:
       >   >
       >   >
       >   >   I think it was David Howie who wrote about the box rule, and
       it just
       >   > shows up in my posts because I keep on replying in the same
thread.

       >   >
       >   >   Any ideas David?
       >   >
       >   >   BTW, If I wanted to race on Lake Geneva, I'd be much more
       likely to
       >   > want something like those Décision 35's for which you provided a
       >   link..
       >   > That was you, Dominique, wasn't it?  In any case, I'm astounded
       by the
       >   > sail area carried by those boats, and am truly amazed with the
       video
       >   > that shows them flying hulls and sailing at speed without a single

       >   > whitecap to be seen.  I'd simply love to sail one for a few days.

       >   >
       >   >   Those boats are way too finicky and fragile for something I'd
       get,
       >   > provided I could afford one in the first place, but there's no
       denying
       >   > that they are masterful speed machines, especially for light air.

       >   While
       >   > I love the schooner rig with flexible unstayed masts, I'm
       viewing this
       >   > from the perspective of racing single-handed in gusty
       conditions.  In a
       >   > real race, in low wind, with crews that know what they are
       doing, I'd
       >   > have a hard time imagining anything beating  a Décision 35.
       >   >
       >   >   I don't truly want one of those fast cats for a variety of
       reasons,
       >   > but they sure do make me drool.  I'm going to go look at some
       Décision
       >   > 35 photos now, and maybe watch that video again.
       >   >
       >   >
       >   >        - Mike
       >   >
       >   >
       >   >
       >   > dominiquebovey wrote:
       >   >
       >   > > Hi,
       >   > > Mike just wrote about an 8.5m "box rule". On Lake Geneva,
       switzerland,
       >   > > there are two multihull classes, M1 (10.8m hull length,
       >   > > Alinghi/Bertarelli is doing this) and M2 (8.5m), see this link:
       >   > > http://www.regates.ch/index.asp?ID=354.
       >   > > My conceptions of rig stiffness are somehow influenced by the
   sail
       >   > > areas you see on the diagram... And lake geneva is terrible
       for wind,
       >   > > with most summer races in ghosting conditions (including the
   "bold
       >   > > d'or"), but in spring and fall there can be quite a lot of
wind.
       >   > > What is the "box rule" you are talking about,Mike?
       >   > >
       >   > >
       >   >
       >
       >
       >
       >
       >
       >
       >


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From: David Howie

To: harryproa@...

Sent: Sunday, January 29, 2006 7:10 AM

Subject: Re: [harryproa] Re: 8.5m multi

Thanks, I was going to try High Modulus ( the boss lives just over the hill
from here), on the materials list for harrigami which I',m using as a guide
for harry you simply give a price for a prof. made spar and suggest a new
system that will reduce the figure significantly. I'm assuming that since that
was written the new system is up and running, care to comment on relative
price now it's been done.

------ Original Message ------
Received: Sat, 28 Jan 2006 12:02:16 AM MST
From: "Rob Denney" <proa@...>
To: <harryproa@...>
Subject: Re: [harryproa] Re: 8.5m multi

G'day,

The thicker the tow, the lower the cost.  200 gsm carbon cloth is made from 3k
tow k stands for thousand, 3k is 3,000 filaments per tow.  We use 48, 50 or 80
and I am trying to get some 160k.  T300 or equivalent is the grade you want.
Otherwise known as standard modulus.

There is a world wide shortage of carbon at the moment, probably till the end
of this year, when with new plants coming on line, there may be a glut.  The
price is high at the moment,. will reduce when the new plant come on line,
regardless of a glut or not. 

We were paying $US7.70 per pound, ex Texas a year or so ago.  Finding it very
hard to get any at all at the moment.  When we do get some, it will be a big
order.  You are welcome to include your order in ours and receive our price.


regards,

rob
  ----- Original Message -----
  From: David Howie
  To: harryproa@...
  Sent: Friday, January 27, 2006 9:40 AM
  Subject: Re: [harryproa] Re: 8.5m multi


  I'm going over the material list trying to get prices here, can you tell me
what I should be asking for regards the carbon tow, seems it comes in a
variety of shapes and sizes.

  Thanks


  ------ Original Message ------
  Received: Thu, 26 Jan 2006 03:30:13 AM MST
  From: "Rob Denney" <proa@...>
  To: <harryproa@...>
  Subject: Re: [harryproa] Re: 8.5m multi "box rule"




  G'day,

  When is the Bol d'Or this year?  Would be glad to sail it with you of we can
get the boat to and from Belgium to Switzerland.   Fun would be no problem,
beating the M2's may be.

  A una rigged El with carbon/nomex, pressure moulded everything looks like it
will be near enough 90 kgs.    An 8.5m would be less than 150% of this

  For light air sailing mast height is everything (see Bethwaites book) as
wind strength increases rapidly with height.  Therefore the highest mast
possible would be the aim, rather than the largest sail area.  The problem
then becomes what to do with the extra height in a breeze.  One possibility
with a mast with no external fittings (forestay, wishbone, etc) is a
telescoping mast.  Doing this with a round mast is pretty difficult, but with
a wing mast  it would a lot easier.  Would not be as quick as hoisting/dousing
a headsail, but in a race where it is either windy or not, it has some
potential. 

  regards,

  rob   ----- Original Message -----
    From: dominiquebovey
    To: harryproa@...
    Sent: Thursday, January 26, 2006 1:24 PM
    Subject: [harryproa] Re: 8.5m multi "box rule"


    Rob,
    I am DEFINITELY interested to sail the Elementarry, and yes you're
    probably right, do the bol d'Or unofficially with a crew of two.
    One one the goals is putting my company name on the sails o hulls, and
    even unofficially it will get some media coverage... The main goal
    being to have fun!
    The 8.5m EL would be less than 200kg racing, the 8.5m cats weigh a
    little less than 400kg, so EL needs about 2x less sail area for the
    same sail/displ ratio, Hence the Melges sails. Also a way to limit costs.

    But it might be possible to find sails designed for the 8.5m, therefor
    DOUBLING the ratio! Might be overkill, and difficult engineeringwise.

    --- In harryproa@..., "Rob Denney" <proa@i...> wrote:
    >
    > G'day,
    >
    > Fixed length is not a proa strong point.  I am not sure whether the
    weight and windage savings possible with a proa would offset that or
    not.  It would certainly cost a lot less.  I would love to have a go
    at designing something for it..   There are a few areas that proas can
    exploit that are not open to cats.  
    >
    > Maybe wait and see how the Elementarry being built in Belgium goes
    against the Tornados (this summer, I hope)  and then look at what
    should be scaled up and what can be reduced.  Incidentally, I will not
    be competing in  the Bol d'Or (hope to be racing Blind Date in
    Denmark), but the boat is available for charter if you or anyone is
    interested.  I would advise that you do it unofficially with two crew,
    rather than officially with three. 
    >
    > Could you let us know the beam, mast height and sail area of the M2
    class, please.  On the web page it looked like 70 sqm upwind, plus a
    similar size screecher, but this does not tally with the Melges sails.
    On this subject, I think the melges sails would be too light, and not
    of optimum plan form for a light air boat which would have a near
    rectangular main. 
    >
    > regards,
    >
    > rob
    >
    >
    >   Sorry for misquoting, David mentioned this box rule naturally.
    >
    >   Yes these crazy boats are incredible, I have seen them flying a hull
    >   on flat water, 8kn of speed with 5kn of wind. They work by creating
    >   their apparent wind. But their top speed is estimated at 30kn.
    >
    >   The last horrible wind-less Bol d'Or was done with "winds averaging 3
    >   knots", the winner took 18 hours for the 100 miles. That is beyond my
    >   nerves anyway.
    >
    >   There are two classes. the M1 (only Decision 35 today) are machines
    >   costing half a million swiss francs (about the same in AUD), with a
    >   racing budget of maybe half that on top of it every year. The
pre-preg
    >   hull skin is less tha a millimeter thick...
    >   And they are low cost machines versus the f40 they had before! A very
    >   well known owner of D35 is bertarelli, yes the poor guy who owns
    >   alinghi and the america cup... Well I do not have any prospect of
    >   competing (financially) for some time to come, even if I am a rather
    >   optimistic type.... But this might be a job for a Turbo-Harrigami.
    >
    >   But there is the M2 class, and the M2 are much more "accessible" (for
    >   a catamaran, around 100kCHF). The M2 are very close in performance to
    >   the M1, and I would be very happy to be in the 10 first of the Bol
    >   d'Or to start...
    >
    >   A HarryM2 would probably cost much less than that (Rob, am I right?),
    >   because of the structural advantage, and would be competitive with
    >   much less high tech gear than the cats and tris in this class. It
    >   would be nice to be competitive with wood-epoxy hulls and minimal use
    >   of carbon (only rig and beams), against all-carbon-kevlar racing
    >   machines. Kind of David against Goliath. But David still needs a good

    >   slingshot! And HarryM2 would still need a lot a sail.
    >
    >   To decrease cost while keeping good performance, I am wondering if
the
    >   whole rig for an 8.5m can be built around "standard" sails. For
    >   example, a melges 24 sail plan (24m2 main, 10m2 jib), of which you
    >   find (not very much) used sails for reasonable prices, while only
    >   needing to recut the jib a bit.
    >
    >   --- In harryproa@..., Mike Crawford <jmichael@g...>
    wrote:
    >   >
    >   >
    >   >   I think it was David Howie who wrote about the box rule, and
    it just
    >   > shows up in my posts because I keep on replying in the same thread.

    >   >
    >   >   Any ideas David?
    >   >
    >   >   BTW, If I wanted to race on Lake Geneva, I'd be much more
    likely to
    >   > want something like those Décision 35's for which you provided a
    >   link.. 
    >   > That was you, Dominique, wasn't it?  In any case, I'm astounded
    by the
    >   > sail area carried by those boats, and am truly amazed with the
    video
    >   > that shows them flying hulls and sailing at speed without a single
    >   > whitecap to be seen.  I'd simply love to sail one for a few days.
    >   >
    >   >   Those boats are way too finicky and fragile for something I'd
    get,
    >   > provided I could afford one in the first place, but there's no
    denying
    >   > that they are masterful speed machines, especially for light air.
    >   While
    >   > I love the schooner rig with flexible unstayed masts, I'm
    viewing this
    >   > from the perspective of racing single-handed in gusty
    conditions.  In a
    >   > real race, in low wind, with crews that know what they are
    doing, I'd
    >   > have a hard time imagining anything beating  a Décision 35.
    >   >
    >   >   I don't truly want one of those fast cats for a variety of
    reasons,
    >   > but they sure do make me drool.  I'm going to go look at some
    Décision
    >   > 35 photos now, and maybe watch that video again.
    >   >
    >   >
    >   >        - Mike
    >   >
    >   >
    >   >
    >   > dominiquebovey wrote:
    >   >
    >   > > Hi,
    >   > > Mike just wrote about an 8.5m "box rule". On Lake Geneva,
    switzerland,
    >   > > there are two multihull classes, M1 (10.8m hull length,
    >   > > Alinghi/Bertarelli is doing this) and M2 (8.5m), see this link:
    >   > > http://www.regates.ch/index.asp?ID=354.
    >   > > My conceptions of rig stiffness are somehow influenced by the
sail
    >   > > areas you see on the diagram... And lake geneva is terrible
    for wind,
    >   > > with most summer races in ghosting conditions (including the
"bold
    >   > > d'or"), but in spring and fall there can be quite a lot of wind.
    >   > > What is the "box rule" you are talking about,Mike?
    >   > >
    >   > >
    >   >
    >
    >
    >
    >
    >
    >
    >
  
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Guess you could attach an iflatable dinghy to a halyard and send it up/along
the mast top hold horizontal till you sorted the kite thing.
IMHO people spend way too much time obssessing over the capsize thing, in
larger than beach type multis it's not really that likely, certainly not from
wind pressure under normal sailing conditions. If you are offshore in serious
shit the waves will be what get ya.
Still it's interesting to follow all the suggestions, and it would definitely
be great if you could right the boat unaided if the worst were to happen, and
the kite with harry on it's side seems as promising as any.
BTW thought that Reynolds 33 someone sent us to was a cool boat too, think it
would beat harry for speed but not accomodation or price.

------ Original Message ------
Received: Sat, 28 Jan 2006 01:39:58 PM MST
From: Mike Crawford <jmichael@...>
To: harryproa@...
Subject: Re: [harryproa] kite traction

<<wouldn't an airtight/watertight spar be enough to keep from turtling?>>

   One would hope.  ;-)

   Rob once hinted at this in an article a few years back, but I haven't
seen anything since then.  Perhaps someone has done some calculations
along the way.  Once the boat is at 90-100 degrees, there won't be much
heeling moment from the windward hull, but the sail area of the deck
could be an issue, especially if a lot of it is close-weaved mesh or a
solid surface.

   Perhaps a wing-masted schooner rig might have enough buoyancy.  You'd
still have to figure out how to run halyards, though.  Maybe in a
separate sleeve/section?

   Even if the boat does want to keep rotating to turtle, the area of the
sails and the buoyancy of the sealed masts should still give you enough
time to deploy an inflatable righting system.  If you're still in the
boat, of course.

        - Mike



David Howie wrote:

> Wouldn't an airtight/watertight spar be enough to keep from turtling?
>
> ------ Original Message ------
> Received: Sat, 28 Jan 2006 09:53:45 AM MST
> From: Mike Crawford <jmichael@...>
> To: harryproa@...
> Subject: Re: [harryproa] kite traction
>
>
>   That's one of the more unique ideas I've heard.
>
>   Randy Reynolds claims to be perfecting his system for righting the R33
> cats when they go over, and says he has tested the system four times.
> Many people are waiting for the official unveiling.  It's briefly
> described towards the bottom of http://www.r33.com/en/update/index.asp .
>
>   The Firebird catamaran folks sell a compressed gas righting system for
> their 26' catamaran for $4,000, shown on their options page at
> http://www.firebirdcat.com/pricing_and_options.htm/pricing_options.htm .
>
>   I'm waiting to see what Randy claims is so wonderful before getting
> serious about a choice, either for a proa or for the current boat.
>
>   As for the kites, they are one of the few ways I can think of to right
> a boat on on your own.  If you can set up a compressed gas righting
> system to keep the boat from going turtle, then you won't need a large
> kite at all.  If the boat is all the way over, you'll need a lot more
> lift.
>
>   You could conceivably strap a carbon spar underneath the deck, erect
> it once the boat has turned turtle, stay it to the leeward hull, and fly
> either an outleader or a water-relaunchable traction kite from it.  I'd
> want the spar for two reasons:
>
>     - Outleaders won't likely want to launch, or relaunch, especially
> when wet, without something that will lift them off the deck/water.
>
>     - Any kite powerful enough to generate 400Kg of lift will likely be
> too dangerous to handle.  I've spent years traction kiting on land, and
> shudder to think about controlling that kind of force.  It will be safer
> to use a much smaller kite, with a more horizontal force, and use the
> righting moment of a spar to your advantage.
>
>   The outleader would certainly make sense if you already have it on
> board.   Of course, then you might have to swim to get it.  I'd probably
> have an emergency bag strapped or built into the underside of the deck,
> or along one of the beams, with the necessary kite, lines, cell phone,
> handheld vhf, flares, and so forth.  This is what I'm working on for the
> current catamaran, minus the traction kite, just in case.
>
>   You might need that spar for righting in any event, even with a
> support boat.  A number of racing and pocket cruising cats can be
> somewhat easily righted by reverse pitchpoling them, but i don't believe
> that a proa will lend itself to going end-over-end.
>
>   Everything would be easier if there were some sort of inflatable
> righting system to prevent the boat from going all the way over.  Plus,
> even if the boat were to turtle, flotation would still make righting it
> easier.
>
>        - Mike
>
>
> Robert wrote:
>
> > Looking at the kite boarders I started to think about how much traction
> > a kite has. It would not take a very large kite to lift the lw hull out
> > of the water and back over where it belongs if you were unlucky to be
> > flipped by a wave. For a Harry 12m lw hull it weighs less than 350kg. A
> > couple of powerfoils can generate that much lift, so surely an
> > outleader kite should be able to drag the lw hull up and over.
> > Is my arithmetic correct. I am not sure how easy it would be to turn
> > the boat upside down to try it but It would be an ineresting exercise.
> > It might need a little mast head bouyancy added using the halliards in
> > light airs. The concept could be tried out with a beach cat and a kite
> > from a kite board.
> > Regards,
> > Robert
> >
> >
> >
> >
> >
> > ------------------------------------------------------------------------
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> >
> >     * To visit your group on the web, go to:
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> >
> >
>
>
>
>
>
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>       Service <http://au.docs.yahoo.com/info/terms/>.
>
>

Thanks, I was going to try High Modulus ( the boss lives just over the hill
from here), on the materials list for harrigami which I',m using as a guide
for harry you simply give a price for a prof. made spar and suggest a new
system that will reduce the figure significantly. I'm assuming that since that
was written the new system is up and running, care to comment on relative
price now it's been done.

------ Original Message ------
Received: Sat, 28 Jan 2006 12:02:16 AM MST
From: "Rob Denney" <proa@...>
To: <harryproa@...>
Subject: Re: [harryproa] Re: 8.5m multi

G'day,

The thicker the tow, the lower the cost.  200 gsm carbon cloth is made from 3k
tow k stands for thousand, 3k is 3,000 filaments per tow.  We use 48, 50 or 80
and I am trying to get some 160k.  T300 or equivalent is the grade you want.
Otherwise known as standard modulus.

There is a world wide shortage of carbon at the moment, probably till the end
of this year, when with new plants coming on line, there may be a glut.  The
price is high at the moment,. will reduce when the new plant come on line,
regardless of a glut or not.

We were paying $US7.70 per pound, ex Texas a year or so ago.  Finding it very
hard to get any at all at the moment.  When we do get some, it will be a big
order.  You are welcome to include your order in ours and receive our price.


regards,

rob
   ----- Original Message -----
   From: David Howie
   To: harryproa@...
   Sent: Friday, January 27, 2006 9:40 AM
   Subject: Re: [harryproa] Re: 8.5m multi


   I'm going over the material list trying to get prices here, can you tell me
what I should be asking for regards the carbon tow, seems it comes in a
variety of shapes and sizes.

   Thanks


   ------ Original Message ------
   Received: Thu, 26 Jan 2006 03:30:13 AM MST
   From: "Rob Denney" <proa@...>
   To: <harryproa@...>
   Subject: Re: [harryproa] Re: 8.5m multi "box rule"




   G'day,

   When is the Bol d'Or this year?  Would be glad to sail it with you of we can
get the boat to and from Belgium to Switzerland.   Fun would be no problem,
beating the M2's may be.

   A una rigged El with carbon/nomex, pressure moulded everything looks like it
will be near enough 90 kgs.    An 8.5m would be less than 150% of this

   For light air sailing mast height is everything (see Bethwaites book) as
wind strength increases rapidly with height.  Therefore the highest mast
possible would be the aim, rather than the largest sail area.  The problem
then becomes what to do with the extra height in a breeze.  One possibility
with a mast with no external fittings (forestay, wishbone, etc) is a
telescoping mast.  Doing this with a round mast is pretty difficult, but with
a wing mast  it would a lot easier.  Would not be as quick as hoisting/dousing
a headsail, but in a race where it is either windy or not, it has some
potential.

   regards,

   rob   ----- Original Message -----
     From: dominiquebovey
     To: harryproa@...
     Sent: Thursday, January 26, 2006 1:24 PM
     Subject: [harryproa] Re: 8.5m multi "box rule"


     Rob,
     I am DEFINITELY interested to sail the Elementarry, and yes you're
     probably right, do the bol d'Or unofficially with a crew of two.
     One one the goals is putting my company name on the sails o hulls, and
     even unofficially it will get some media coverage... The main goal
     being to have fun!
     The 8.5m EL would be less than 200kg racing, the 8.5m cats weigh a
     little less than 400kg, so EL needs about 2x less sail area for the
     same sail/displ ratio, Hence the Melges sails. Also a way to limit costs.

     But it might be possible to find sails designed for the 8.5m, therefor
     DOUBLING the ratio! Might be overkill, and difficult engineeringwise.

     --- In harryproa@..., "Rob Denney" <proa@i...> wrote:
     >
     > G'day,
     >
     > Fixed length is not a proa strong point.  I am not sure whether the
     weight and windage savings possible with a proa would offset that or
     not.  It would certainly cost a lot less.  I would love to have a go
     at designing something for it..   There are a few areas that proas can
     exploit that are not open to cats.
     >
     > Maybe wait and see how the Elementarry being built in Belgium goes
     against the Tornados (this summer, I hope)  and then look at what
     should be scaled up and what can be reduced.  Incidentally, I will not
     be competing in  the Bol d'Or (hope to be racing Blind Date in
     Denmark), but the boat is available for charter if you or anyone is
     interested.  I would advise that you do it unofficially with two crew,
     rather than officially with three.
     >
     > Could you let us know the beam, mast height and sail area of the M2
     class, please.  On the web page it looked like 70 sqm upwind, plus a
     similar size screecher, but this does not tally with the Melges sails.
     On this subject, I think the melges sails would be too light, and not
     of optimum plan form for a light air boat which would have a near
     rectangular main.
     >
     > regards,
     >
     > rob
     >
     >
     >   Sorry for misquoting, David mentioned this box rule naturally.
     >
     >   Yes these crazy boats are incredible, I have seen them flying a hull
     >   on flat water, 8kn of speed with 5kn of wind. They work by creating
     >   their apparent wind. But their top speed is estimated at 30kn.
     >
     >   The last horrible wind-less Bol d'Or was done with "winds averaging 3
     >   knots", the winner took 18 hours for the 100 miles. That is beyond my
     >   nerves anyway.
     >
     >   There are two classes. the M1 (only Decision 35 today) are machines
     >   costing half a million swiss francs (about the same in AUD), with a
     >   racing budget of maybe half that on top of it every year. The
pre-preg
     >   hull skin is less tha a millimeter thick...
     >   And they are low cost machines versus the f40 they had before! A very
     >   well known owner of D35 is bertarelli, yes the poor guy who owns
     >   alinghi and the america cup... Well I do not have any prospect of
     >   competing (financially) for some time to come, even if I am a rather
     >   optimistic type.... But this might be a job for a Turbo-Harrigami.
     >
     >   But there is the M2 class, and the M2 are much more "accessible" (for
     >   a catamaran, around 100kCHF). The M2 are very close in performance to
     >   the M1, and I would be very happy to be in the 10 first of the Bol
     >   d'Or to start...
     >
     >   A HarryM2 would probably cost much less than that (Rob, am I right?),
     >   because of the structural advantage, and would be competitive with
     >   much less high tech gear than the cats and tris in this class. It
     >   would be nice to be competitive with wood-epoxy hulls and minimal use
     >   of carbon (only rig and beams), against all-carbon-kevlar racing
     >   machines. Kind of David against Goliath. But David still needs a good

     >   slingshot! And HarryM2 would still need a lot a sail.
     >
     >   To decrease cost while keeping good performance, I am wondering if
the
     >   whole rig for an 8.5m can be built around "standard" sails. For
     >   example, a melges 24 sail plan (24m2 main, 10m2 jib), of which you
     >   find (not very much) used sails for reasonable prices, while only
     >   needing to recut the jib a bit.
     >
     >   --- In harryproa@..., Mike Crawford <jmichael@g...>
     wrote:
     >   >
     >   >
     >   >   I think it was David Howie who wrote about the box rule, and
     it just
     >   > shows up in my posts because I keep on replying in the same thread.

     >   >
     >   >   Any ideas David?
     >   >
     >   >   BTW, If I wanted to race on Lake Geneva, I'd be much more
     likely to
     >   > want something like those Décision 35's for which you provided a
     >   link..
     >   > That was you, Dominique, wasn't it?  In any case, I'm astounded
     by the
     >   > sail area carried by those boats, and am truly amazed with the
     video
     >   > that shows them flying hulls and sailing at speed without a single
     >   > whitecap to be seen.  I'd simply love to sail one for a few days.
     >   >
     >   >   Those boats are way too finicky and fragile for something I'd
     get,
     >   > provided I could afford one in the first place, but there's no
     denying
     >   > that they are masterful speed machines, especially for light air.
     >   While
     >   > I love the schooner rig with flexible unstayed masts, I'm
     viewing this
     >   > from the perspective of racing single-handed in gusty
     conditions.  In a
     >   > real race, in low wind, with crews that know what they are
     doing, I'd
     >   > have a hard time imagining anything beating  a Décision 35.
     >   >
     >   >   I don't truly want one of those fast cats for a variety of
     reasons,
     >   > but they sure do make me drool.  I'm going to go look at some
     Décision
     >   > 35 photos now, and maybe watch that video again.
     >   >
     >   >
     >   >        - Mike
     >   >
     >   >
     >   >
     >   > dominiquebovey wrote:
     >   >
     >   > > Hi,
     >   > > Mike just wrote about an 8.5m "box rule". On Lake Geneva,
     switzerland,
     >   > > there are two multihull classes, M1 (10.8m hull length,
     >   > > Alinghi/Bertarelli is doing this) and M2 (8.5m), see this link:
     >   > > http://www.regates.ch/index.asp?ID=354.
     >   > > My conceptions of rig stiffness are somehow influenced by the
sail
     >   > > areas you see on the diagram... And lake geneva is terrible
     for wind,
     >   > > with most summer races in ghosting conditions (including the
"bold
     >   > > d'or"), but in spring and fall there can be quite a lot of wind.
     >   > > What is the "box rule" you are talking about,Mike?
     >   > >
     >   > >
     >   >
     >
     >
     >
     >
     >
     >
     >

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--- In harryproa@..., Mike Crawford <jmichael@g...>
wrote:
>
>
> Robert wrote:
>
> > I am not quite sure if I am on the same planet as those who
persist
> > in a lw pod for a sailing proa. Am I missing somethingin my
> > understanding of hydrodynamics and hydrostatics. My calculatons
for
> > the hydrostaics show the boat has a greater tendancy to keep going
> > over if slightly >90degrees as the ww hull is more likely to go
paast
> > top dead centre.
>
>
>   I think some of the pacific proa designs can be amazingly
efficient
> when given just the right conditions, which is probably why some
favor
> them.
In general we don't have a great deal of disagreement
I agree about the pacific proa. For example Elementarry. Though
Elementarry may be even faster though not as easy to sail in Atlantic
mode. keeping the lee hull just out of the water in low winds and
more righting moment with the ww hull just skimmming the water in
higher winds. Would not be easy but theoretically faster. I have
sketches for a monocoque proa with a fold out cockpit based on an
elementarry that I reckon would be a little bit better as an Atlantic
schooner  

>
>   With more weight in the large leeward hull, you can theoretically
cut
> down on hydrodynamic drag.  Check out the comparison chart halfway
down
> the page on
> http://proafile.com/view/weblog/comments/cheap_capable_cruisers_iii/
>
>   If you can get the weight in the long hull, and then either
lighten
> the windward hull, fly the windward hull, or use it as a vector
fin, you
> can probably get more speed for less sail area.  I've not taken
fluid
> mechanics, but I'll buy the argument.

I have actually taken fluid dynamics. I am suspending judgement on
the vector fin and generally agree that if you keep the weight on one
hull then you lessen drag. You can lessen drag at low speeds even
more by going to a fat mono. But you also need righting moment to
generate power. Probably this can be done with a vector fin but it
seems much more reliable to  use weight not needed in the lw hull. If
the vector fin works as claimed , then it is contributing to extra
downward force overall on the boat,ie  equivalent to extra overall
weight similar to water ballast. Jzerro used water ballast to get the
righting moment and needed more sail area than equivalent length harry
This doesn't tally with less weight less drag less sail area.
I spent a few years in PNG and had experience with some of their 40'
racing canoes. They had plenty of crew constantly racing backwards
and forwards keeping the canoe balanced but once a bit of wind came
up they were all, but the steersman, on the outrigger. This is in
steady trade wind conditions.
If you are going to rely on moving human ballast around constantly
then a Pacific proa works very nicely and using semistayed masts is
probably the lightest engineering. With the use of unstayed msats I
calculate things  change to an Atlantic rig. For a long term offshore
boat you don't want to be living on the edge constantly so for safety
considerations you put all the necessary weight that you can in the
ww hull as permanent righting moment- within reason- you need some
weight in lw hull. The Atlantic rig has the problem of interfering
with accommodation and sheeting arrangements that make it difficult
for weather cocking. The amount of weight in the rig seems a good
compromise for the lw hull and bouyant masts can help prevent
complete overturning if someone is mug enough to leave the sheets
cleated with ridiculous amounts of sail in lumpy seas.

My objection wasn't with the Pacific proa. I have great fondness for
it after my time in PNG. I believe it has its place but not for long
haul cruising. My objection is the use of the lee pod as I believe
that it is an unseaworthy attachment. I can almost see some value in
it for flat seas as training wheels and as a lee platform for
drifting conditions but not once there is any swell. I can't see how
it can help prevent combination wind/wave capsize. On the side of a
wave the boat would have to be about 90 degrees before the leepod
contributed to righting moment. In breaking seas, if hit from the
side by a breaking wave it could dig in and flip the boat. It also
makes the boat less likely to be stabilised by mast bouyancy from
going over further.
Rob has iterated most of these point many times. This is based on
his undertanding of the engineering and many years experience in all
sorts of sailing craft in all sorts of conditions. My experience of
the sea as a professional fisherman working in Bass Strait and many
years of surfing various craft, coupled with a degree in mathematics
fully support his reasoning.


  This would be why Jzerro can do
> 20 knots without a whole lot of righting moment.  It's kind of an
> evolution of the proa mantra: less weight, less drag, less sail
area,
> and yet more speed.
>
>   This really comes true in the vector fin proa that is shown at
> http://www.proadesign.com/ .  I'm sure that thing is wicked fast
given
> the right conditions.  The designer even claims it will hang on the
edge
> of a vertical wave face, which might even be true if you're moving
the
> right way.  This might be true, but since he won't let anyone sail
with
> him, or race against him, it's tough to tell.
>
>   However, we don't always sail in just the right conditions.  As
Rob
> has pointed out, if that windward vector fin were to come out of
the
> water, or get fouled with a plastic bag or seaweed, you could be in
a
> world of trouble.  Likewise, if you were to get a solid gust when
fying
> a hull on Jzerro, there wouldn't be much to stop you from going
over. 
> The leeward pod overhang would help, but I'm not sure I'd want to
try it.
>
>   The Harry proa might have more drag than a traditional pacific
proa,
> but there's more to a fast boat than drag.  A greater righting
moment
> means more sail area, and more lift, and that can mean a lot.  Then
> Imagine what you can do when skimming or flying the ww hull of a
harry!
>
>    It's also nice to have a greater righting moment if you're
heading
> windward in big weather, or trying to ride out a storm.  With
rudders up
> and sails or bare poles to leeward, the harryproa will tend to
itself
> quite nicely.
>
>   The "dutch proa" at http://www.bijlard.demon.nl/ is pretty
> interesting.  That additional leeward pod/ama would certainly help,
and
> would be a great point of balance where you could fly a hull, and
then
> adjust sheet loads to keep both amas out of the water without
worrying
> about imminent capsize.  As some have noted, though, it's really a
> stunted trimaran, and the extra weight would be better used for
righting
> moment.
>
>   In the end, the harryproa seems to be the best approach to a
series of
> conflicting design goals (including speed vs. safety), and as side
> benefits, it also manages to keep masts and daggerboards out of the
hull
> with the accommodations, and it can even be tacked or backwinded
without
> major issues.
>
>   However, i can see why the purists out there like the less-is-
more
> solution of the pod in the leeward hull.
>
>        - Mike
>

Wouldn't an airtight/watertight spar be enough to keep from turtling?

------ Original Message ------
Received: Sat, 28 Jan 2006 09:53:45 AM MST
From: Mike Crawford <jmichael@...>
To: harryproa@...
Subject: Re: [harryproa] kite traction


  That's one of the more unique ideas I've heard.

  Randy Reynolds claims to be perfecting his system for righting the R33
cats when they go over, and says he has tested the system four times. 
Many people are waiting for the official unveiling.  It's briefly
described towards the bottom of http://www.r33.com/en/update/index.asp .

  The Firebird catamaran folks sell a compressed gas righting system for
their 26' catamaran for $4,000, shown on their options page at
http://www.firebirdcat.com/pricing_and_options.htm/pricing_options.htm .

  I'm waiting to see what Randy claims is so wonderful before getting
serious about a choice, either for a proa or for the current boat.

  As for the kites, they are one of the few ways I can think of to right
a boat on on your own.  If you can set up a compressed gas righting
system to keep the boat from going turtle, then you won't need a large
kite at all.  If the boat is all the way over, you'll need a lot more lift.

  You could conceivably strap a carbon spar underneath the deck, erect
it once the boat has turned turtle, stay it to the leeward hull, and fly
either an outleader or a water-relaunchable traction kite from it.  I'd
want the spar for two reasons:

    - Outleaders won't likely want to launch, or relaunch, especially
when wet, without something that will lift them off the deck/water.

    - Any kite powerful enough to generate 400Kg of lift will likely be
too dangerous to handle.  I've spent years traction kiting on land, and
shudder to think about controlling that kind of force.  It will be safer
to use a much smaller kite, with a more horizontal force, and use the
righting moment of a spar to your advantage.

  The outleader would certainly make sense if you already have it on
board.   Of course, then you might have to swim to get it.  I'd probably
have an emergency bag strapped or built into the underside of the deck,
or along one of the beams, with the necessary kite, lines, cell phone,
handheld vhf, flares, and so forth.  This is what I'm working on for the
current catamaran, minus the traction kite, just in case.

  You might need that spar for righting in any event, even with a
support boat.  A number of racing and pocket cruising cats can be
somewhat easily righted by reverse pitchpoling them, but i don't believe
that a proa will lend itself to going end-over-end.

  Everything would be easier if there were some sort of inflatable
righting system to prevent the boat from going all the way over.  Plus,
even if the boat were to turtle, flotation would still make righting it
easier.

       - Mike


Robert wrote:

> Looking at the kite boarders I started to think about how much traction
> a kite has. It would not take a very large kite to lift the lw hull out
> of the water and back over where it belongs if you were unlucky to be
> flipped by a wave. For a Harry 12m lw hull it weighs less than 350kg. A
> couple of powerfoils can generate that much lift, so surely an
> outleader kite should be able to drag the lw hull up and over.
> Is my arithmetic correct. I am not sure how easy it would be to turn
> the boat upside down to try it but It would be an ineresting exercise.
> It might need a little mast head bouyancy added using the halliards in
> light airs. The concept could be tried out with a beach cat and a kite
> from a kite board.
> Regards,
> Robert
>
>
>
>
>
> ------------------------------------------------------------------------
> *Yahoo! Groups Links*
>
>     * To visit your group on the web, go to:
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>       
>     * To unsubscribe from this group, send an email to:
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>       Service <http://au.docs.yahoo.com/info/terms/>.
>
>

Wouldn't an airtight/watertight spar be enough to keep from turtling?

------ Original Message ------
Received: Sat, 28 Jan 2006 09:53:45 AM MST
From: Mike Crawford <jmichael@...>
To: harryproa@...
Subject: Re: [harryproa] kite traction


   That's one of the more unique ideas I've heard.

   Randy Reynolds claims to be perfecting his system for righting the R33
cats when they go over, and says he has tested the system four times.
Many people are waiting for the official unveiling.  It's briefly
described towards the bottom of http://www.r33.com/en/update/index.asp .

   The Firebird catamaran folks sell a compressed gas righting system for
their 26' catamaran for $4,000, shown on their options page at
http://www.firebirdcat.com/pricing_and_options.htm/pricing_options.htm .

   I'm waiting to see what Randy claims is so wonderful before getting
serious about a choice, either for a proa or for the current boat.

   As for the kites, they are one of the few ways I can think of to right
a boat on on your own.  If you can set up a compressed gas righting
system to keep the boat from going turtle, then you won't need a large
kite at all.  If the boat is all the way over, you'll need a lot more lift.

   You could conceivably strap a carbon spar underneath the deck, erect
it once the boat has turned turtle, stay it to the leeward hull, and fly
either an outleader or a water-relaunchable traction kite from it.  I'd
want the spar for two reasons:

     - Outleaders won't likely want to launch, or relaunch, especially
when wet, without something that will lift them off the deck/water.

     - Any kite powerful enough to generate 400Kg of lift will likely be
too dangerous to handle.  I've spent years traction kiting on land, and
shudder to think about controlling that kind of force.  It will be safer
to use a much smaller kite, with a more horizontal force, and use the
righting moment of a spar to your advantage.

   The outleader would certainly make sense if you already have it on
board.   Of course, then you might have to swim to get it.  I'd probably
have an emergency bag strapped or built into the underside of the deck,
or along one of the beams, with the necessary kite, lines, cell phone,
handheld vhf, flares, and so forth.  This is what I'm working on for the
current catamaran, minus the traction kite, just in case.

   You might need that spar for righting in any event, even with a
support boat.  A number of racing and pocket cruising cats can be
somewhat easily righted by reverse pitchpoling them, but i don't believe
that a proa will lend itself to going end-over-end.

   Everything would be easier if there were some sort of inflatable
righting system to prevent the boat from going all the way over.  Plus,
even if the boat were to turtle, flotation would still make righting it
easier.

        - Mike


Robert wrote:

> Looking at the kite boarders I started to think about how much traction
> a kite has. It would not take a very large kite to lift the lw hull out
> of the water and back over where it belongs if you were unlucky to be
> flipped by a wave. For a Harry 12m lw hull it weighs less than 350kg. A
> couple of powerfoils can generate that much lift, so surely an
> outleader kite should be able to drag the lw hull up and over.
> Is my arithmetic correct. I am not sure how easy it would be to turn
> the boat upside down to try it but It would be an ineresting exercise.
> It might need a little mast head bouyancy added using the halliards in
> light airs. The concept could be tried out with a beach cat and a kite
> from a kite board.
> Regards,
> Robert
>
>
>
>
>
> ------------------------------------------------------------------------
> *Yahoo! Groups Links*
>
>     * To visit your group on the web, go to:
>       http://au.groups.yahoo.com/group/harryproa/
>
>     * To unsubscribe from this group, send an email to:
>       harryproa-unsubscribe@...
>       <mailto:harryproa-unsubscribe@...?subject=Unsubscribe>
>
>     * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
>       Service <http://au.docs.yahoo.com/info/terms/>.
>
>

Looking at the kite boarders I started to think about how much traction
a kite has. It would not take a very large kite to lift the lw hull out
of the water and back over where it belongs if you were unlucky to be
flipped by a wave. For a Harry 12m lw hull it weighs less than 350kg. A
couple of powerfoils can generate that much lift, so surely an
outleader kite should be able to drag the lw hull up and over.
Is my arithmetic correct. I am not sure how easy it would be to turn
the boat upside down to try it but It would be an ineresting exercise.
It might need a little mast head bouyancy added using the halliards in
light airs. The concept could be tried out with a beach cat and a kite
from a kite board.
Regards,
Robert

Looking at the kite boarders I started to think about how much traction
a kite has. It would not take a very large kite to lift the lw hull out
of the water and back over where it belongs if you were unlucky to be
flipped by a wave. For a Harry 12m lw hull it weighs less than 350kg. A
couple of powerfoils can generate that much lift, so surely an
outleader kite should be able to drag the lw hull up and over.
Is my arithmetic correct. I am not sure how easy it would be to turn
the boat upside down to try it but It would be an ineresting exercise.
It might need a little mast head bouyancy added using the halliards in
light airs. The concept could be tried out with a beach cat and a kite
from a kite board.
Regards,
Robert

Looking at the kite boarders I started to think about how much traction
a kite has. It would not take a very large kite to lift the lw hull out
of the water and back over where it belongs if you were unlucky to be
flipped by a wave. For a Harry 12m lw hull it weighs less than 350kg. A
couple of powerfoils can generate that much lift, so surely an
outleader kite should be able to drag the lw hull up and over.
Is my arithmetic correct. I am not sure how easy it would be to turn
the boat upside down to try it but It would be an ineresting exercise.
It might need a little mast head bouyancy added using the halliards in
light airs. The concept could be tried out with a beach cat and a kite
from a kite board.
Regards,
Robert