Subject: Re: [harryproa] Re: Rig - windward or leeward?
From: Dennis Cox
Date: 11/11/2010, 4:25 PM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

 

Todd,
 
I guess I should field that one...
All the 3D images showing the boat in the water were for the same load condition. 
 
(1) They depict the boat at gross weight 10,000 lbs, with the windward hull "just" flying.  That waterline you see on the lee hull accounts for the full 10,000 lb displacement. 
(2) It also accounts for drive trying to bury the nose.  It accounts for the drag predictions out of Godzilla at 30 knots and the COE height shoving the nose down.  This should be conservative since Rick's analyses using Flotilla indicates there should be some dynamic lift at the front due to wave theory.
 
So... with a lot of hand waving, rose colored glasses and number crunching... the nose should float no lower than this.
 
THEN the real worlds comes in and smacks it around with waves and gusts and ALL bets are off!
 
Me... I'd be happy as a clam with 20 knots and a Mai Tai in hand.
You'll note... I switched the wings to the lee hull.  I rode the fence for a long time... until Rob mentioned, "imagine sitting on your upper bridge between the wings and check out the view."  So I'm not all about speed.  Aesthetics are important too.  :)

Dennis
 
 

From: tsstproa <bitme1234@yahoo.com>
To: harryproa@yahoogroups.com.au
Sent: Thu, November 11, 2010 2:07:18 PM
Subject: [harryproa] Re: Rig - windward or leeward?

 

Yeah the Indian Prao is kool. I love to see a full size boat that reinforces an inkling.

The 60 foot trailerable proa in this forum is awsome too although it looks to be alittle loaded on the leeward hull in the drawings is this static or sailing depiction. Static displacement looks off. If you lowered your windward hull BY raising your leeward hull you will get a better balance all around. As is it looks your center of gravity is starting high on the wheel of rotation before heeling ever begins. Just a thought.

I've always like the idea of relating a proa to a bidirectional open 60 trimaran. Taking off windward ama and using buoyancy vs weight as a common factor in designing a shunting craft.

Or using all three hulls like this ;)
http://www.youtube.com/watch?v=pbScETxFMOU

Or even an bidierctional open 60 mono hull. Even a 30'ter could have 2 queens a galley and a head with space to spare.
http://www.youtube.com/watch?v=spK28yj5cEo

Todd

--- In harryproa@yahoogroups.com.au, "John" <jrwells2007@...> wrote:

the French prao kicked off the current train of thoughts plus the discussions about balancing the centre of effort and centre of lateral resistance.
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