|Subject: Re: [harryproa] design performance|
|From: "Rob Denney" <email@example.com>|
|Date: 4/8/2008, 10:07 PM|
Tricky question, due to the flexing of the mast and the different
weights in the windward hull. From memory, the wind speed if the sail
and mast were rigid was 25 and 22 knots. Reality is closer to 30 and
high twenties. There is a formula (and some really interesting
articles) on John Shuttleworth'
For some reason, some of your posts (and occasionally some other
people's) get stuck in the Yahoo filter and I have to unstick them
Not a big deal, but this explains why sometimes they take a while to
appear. If any posts don't appear, please let me know.
On Tue, Apr 8, 2008 at 4:46 PM, Doug Haines <doha720@yahoo.
> What is the hull flying speed thoretical in Vis and Harry?
> What would it be optimal for racing , cruising. Recall solitarry was 10
> knots or something. Is this best for racing in 10-12 knot winds?
> Rob Denney <harryproa@gmail.
> Not only better load carrying, but better hydrodynamics (higher
> prismatic) and easier to build. My early hulls were drawn to have
> the bow just clear when the stern lifts up, but this does not allow
> for surfing big waves, power reaching and nervous crew. 1m is good,
> the 66'ter in Portugal has 1.3 but it is a pretty heavy boat.
> Solitarry has 600 and it looks very low. Although it is a very light
> boat so will be heaps.
> On Mon, Apr 7, 2008 at 9:35 PM, Robert <cateran1949@
> > I was wondering about the shape of the hulls. If the hulls are
> > completely parallel for the middle two thirds or even 3/4,4/5? and
> > then tapered, the load carrying is increased without going wider. I
> > was also thinking about how high the bows need to be for the lw hull.
> > I can't see why they need to be any heavier than required to have a
> > little reserve bouyancy at the point where the stern just starts to
> > leave the water. This gives approximately 1m for a 15m lw hull fairly
> > loaded with about 4.5 tonnes, but could be only 60cm if you kept the
> > kitchen sink pretty light --- In harryproa@yahoogrou
> > "gardner.pomper" <gardner@...
> > >
> > > Hi,
> > >
> > > My earlier posting, on the Liveaboard 55, kept growing and was getting
> > > too close to being the same boat that Rob is already building for the
> > > 60' charter version. I wanted to give this another try, cutting back
> > > some of the feature creep to get closer to what I (and/or my wife
> > > <grin>) needs, as opposed to everything we both want.
> > >
> > > Along with that, I am adopting Rob's concept of keeping all the living
> > > space out of the hulls, which I am beginning to understand better,
> > > since it would elminate all the interior finishing, which is very time
> > > consuming (read expensive). So, I decided to just draw the bridgedeck,
> > > which can then just be plopped onto the appropriately sized hulls for
> > > the displacement (oversimplification
> > > length, we can just allow the bunks to overhang the ww hull.
> > >
> > > For the weight calculations, I could use some info on what a rule of
> > > thumb is for structure. I have about 600 sq ft of deck (since I want
> > > an exterior walkway from the help to the windward hull) and about 500
> > > sq ft of hardtop. I then estimate 200 sq ft of counter/bunk top and
> > > 400 sq ft of counter/cabinet sides. How do I figure the weights of
> > > this, assuming I use resin infusion over foam, which seems to be the
> > > simplest, lightest way to go?
> > >
> > > Beyond that, I have the following weights (in pounds) for equipment:
> > > 12' catamaran dingy 160
> > > 25HP outboard 150
> > > Propane Stove w/oven 75
> > > diesel generator 350 ?
> > > Lectrasan 25
> > > Head 50
> > > Microwave 30
> > > Fridge/freezer 50
> > > batteries 300
> > > solar panels 150
> > > crew 500
> > > 200 gal water/fuel 1600
> > > provisions 1000 ?
> > > Total 4500 lbs (approx)
> > >
> > > So, if I want to sail at 15 knots in 15 knots of wind, what size hulls
> > > do I need?
> > >
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