Unbalanced Lines Sought

[bhnautika]

Earl I think we need to clarify the style of boat we are taking about and the difference between older style boats and new, model and full size. Older full keelboats tracked pretty well, were general point at both ends and tended to have slack bilges all of which don’t change the waterlines much when heeled.
The philosophy of modern boats is to give them some weather helm so the rudder can provide extra lift, the exact opposite to the balanced hull.
How you want to get stability also plays a roll in the shape of the hull either through form stability or ballast.

[Wardi]

Hello Earl,
Here is a link to a previous discussion in this forum on this topic;

http://boatdesign.net/forums/showthr...l+balance+ward

[tri - star]

.....Perhaps one of the mosts famous " unbalanced " boats ever, was
sailed to Cape Town from Eng. Where the defect was finaly corrected.

Singled Handed by a fellow, who was subsequently, knighted by the Queen
after completing his voyage, in '67.
- Sir Francis Chichester's boat was called Gypsey Moth.

An idication of what a skilled sailor he was - is evidenced - by the fact;
that when a company made a model, of Gypsey Moth: to the orig. specs
....they found it to be virtually uncontrolable !
When they did the same Cape Town mods. the model was transformed.
- The company was much relived, as now they had a product they
could sell, after all.

[Earl Boebert]

Thanks to all for the comments and links and FWIW, my slides and notes are up at:

http://www.usvmyg.org/SlidesWithNotes.pdf

Cheers,

Earl

[Earl Boebert]

Originally Posted by bhnautika

Earl I think we need to clarify the style of boat we are taking about and the difference between older style boats and new, model and full size. Older full keelboats tracked pretty well, were general point at both ends and tended to have slack bilges all of which don’t change the waterlines much when heeled.
The philosophy of modern boats is to give them some weather helm so the rudder can provide extra lift, the exact opposite to the balanced hull.
How you want to get stability also plays a roll in the shape of the hull either through form stability or ballast.

I agree; this might turn out to be nothing more than naval architecture equivalent of those projects that figured out how old catapults worked. It still could be fun, and it would still be interesting to put a scientific basis under Turner's inspired guessing.

Cheers,

Earl