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Old 10-16-2009, 12:25 PM
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BobBill BobBill is offline
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Test/Experiment

Some SA people convinced me dreadnaught bows as worn by 18s and mega cats Alinghi and the BMW beast, were more efficient than traditional bows.

I must take it to the extreme, what works for one, ...

What would it take to convert the below stem to the right side configuration of yellow dinghy hulls to resemble that of hull on Nice Pair, in upper left of bow series shots?

Small dinghy sailboat.

This is simply an experiment of straight-line sailing versus wave-riding.

Need ideas on how to build to reasonable strength.

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Old 10-16-2009, 12:50 PM
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Originally Posted by BobBill View Post

I must take it to the extreme, what works for one, ...
...............does´nt for all! Goes the text!
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Old 10-16-2009, 01:12 PM
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Quote:
Originally Posted by BobBill View Post
Some SA people convinced me dreadnaught bows as worn by 18s and mega cats Alinghi and the BMW beast, were more efficient than traditional bows.

I must take it to the extreme, what works for one, ...

What would it take to convert the below stem to the right side configuration of yellow dinghy hulls to resemble that of hull on Nice Pair, in upper left of bow series shots?

Small dinghy sailboat.

This is simply an experiment of straight-line sailing versus wave-riding.

Need ideas on how to build to reasonable strength.

B-B:

Any design element like the dreadnaught/wave piercing bow has to be executed in concert with the whole boat design. You can't simply mix and match features to arrive at optimal performance, although many people seem to think so.

A typical dinghy design generally has lots of width and volume up front, to facilitate buoyancy over waves. Adding a wave piercing bow would probably slow this type of boat down, as the bow would enter the wave cleanly, and then a large volume of water would be stopped by the wide shoulders and volume of the boat. Kind of like putting a ball point pen in front of an apple body to improve the apple's aerodynamics.

Boats with wave piercing designs are generally very narrow, and the hull passes more through waves than over them.

--
Bill
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Old 10-16-2009, 01:41 PM
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BobBill BobBill is offline
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Piercing Bows

Yes, thanks, Bill.

Kind of advice I have been looking for, besides structural. I understand. And, I do not disagree with you.

But then I got to thinking about the old I-14 I used to sail as crew, with its perpendicular bow.

We called that bow a cutter, and wondered what would have been the result if we had bent it a bit forward? That 14 had typical forward 14 (Proctor) flair with very flat aft run.

Was a wooden boat and we literally tore it apart and stitched (epoxied) it back together, adding a rear chine, copying someone who did it for One-Design Mag in the 60s. boat was fast and strong but still...

If a cutter, why not a bit "Dread Naughty?"

My sense is that the boat will plane normally in a breeze, and cut the wave tops a bit easier without the high horse rock; the down side being, literally hitting the trough and not coming up as fast...the physics being what they are for a heavier hull.

I have an old formula around here someplace, for planing and amplitude sustain or something like that, but way too techy for this, I think.

Still, even if I move to only a cutter bow, I would like to read what some might think about the alteration physically.


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