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

From: Robert

To: harryproa@...

Sent: Monday, November 28, 2005 7:42 AM

Subject: [harryproa] Re: Plane(ing) Proa

ed to design a foil suitable for getting the ww hull up on the plane.
I think it can be done but becomes pretyy mechanically complex as you
have to have means to adjust the foil angle depending on which end is
going forward. The most promising idea I came up with was a pivot
round about the center of the ww hull with the foil at the top having
two long levers, one at each end of the ww hull which is stepped on
and locked down to hold the foil forward and angled for the new
direction. Otherwise cables and a highfield lever. This would be one
more thing to think about with every shunt. Part of the dificulty in
design was keeping the weight sufficently far back to avoid tipping.
This meant having the pivot fairly high. Ideally it would be nice to
have a sensorfoil as in the Hobie foilers to keep the foil angle
optimum but then you need a sensor at each end and a means to connect
and disconnect them. Theoretically this could be done with tensioned
sensor foil that sprung forwared. When loaded going forward the
sensor presses against the tension andd loads the main foil. When
going backwards the sensor foil is sprung out of the way with no load
on the main foil. It may need a foil at each crossbeam to get the
foil sufficiently far forward.
I think it can be done but not easily and not cheaply and would be a
drag at low speeds.
My thoughts on a planing hull design is a fairly flatV bottom but
that the drive from the rig loads the bows and so you would need to
get on a trapeze over the back crossbeam to keep it up.
Robert

 




I tri--- In harryproa@..., "Rob Denney" <proa@i...>
wrote:
> Sailing in my case.  Tried a beam mounted rudder today.  Steers the
boat very well, but a few details still to sort.  Max speed 12 knots
in 10 knots of breeze so I am slowly getting the bugs out.  Went past
an International 14 sailing higher and faster which was very
satisfying.
>
> I tried planing hulls on U (see www.harryproa.com) and they did not
work.  The boat tended to tip forward on the rocker rather than get
up and plane.  The narrow waterplane did not help either.
>
> Rather than having the windward hull plane, you would be better
shifting weight so it flies.  In theory a Harry will beat any of the
F boats, asssuming the standard of gear and crew is the same. 
>
> Spitfire is still down the club as far as I know.  Contact Brett at
Windrush catamarans to make an offer, or I can if you are serious.. 
All the bits are there, and the rumour is that Brett, who built it,
now owns it.  It reached very quickly (30+ knots by some reports) but
was never raced.
>
> regards,
>
> Rob
>   ----- Original Message -----
>   From: jocroome
>   To: harryproa@...
>   Sent: Friday, November 25, 2005 12:02 AM
>   Subject: [harryproa] Plane(ing) Proa
>
>
>   Hi All,
>
>   BacK after a while. See the list is somewhat quiet. Must be all
building or sailing I guess. I
>   see Farrier is finally going to make the 22 footer availablle,
with 4 (maybe a bit tight)
>   berths. I was thinking, one of the reasons the trimaran design is
so fast is because the
>   middle hull planes, thus reducing the wetted area. I wonder, is
it possible to get a HP ww
>   (or both) hull to plane? I would really like an HP that makes a F-
boat look slow, or
>   marginally slow on a wetted area comparison when going fast.
Still dreaming of a no sail,
>   dry, very fast, unequal length (twin float) wind driven boat.
What's the story with Spitfire?
>   Is it still sailable, for sale, and what about the first owner?
Is he/she contactable, was it a
>   dog or what? Love to know (drooling).
>
>   Happy building, sailing, dreaming...
>
>   If it's not a Proa, it's probrably sloa. (thanks Chip for the
spelling lesson, won't do it again)
>   Can't spell in the Southern drawwwwwwl, sorry.
>
>   RC
>
>
>
>
>
> --------------------------------------------------------------------
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