T-Pain Is On A Boat: Re: [Electric Boats] hull design

Tuesday, August 3, 2010

Re: [Electric Boats] hull design

I was thinking too that a cat might be the best answer perhaps with a cross hull hydrofoil to get the hulls patrially out of the water at speed.
Chris S

--- In electricboats@yahoogroups.com, "dennis wolfe" <dwolfe@...> wrote:
>
> Ned, I think you will have to look at a catamaran or trimaran with a very slender center hull. Google "Human Powered Boats" for ideas. There are threads on the boatdesign.net forum that cold be helpful. Search there for posts from Rick Willoughby.
>
> You will not have a high enough power/weight ratio to get a boat to plane in the conventional sense so you are right to look at designs that do not follow the "hull speed" rule.
>
> A Bolger "Sneakeasy" might work; its about the right size. Have you seen the Etec outboard / Sneakeasy by J Rundholm? http://www.psnw.com/~jmrudholm/etekoutboard4.html
>
> He got 10.4 mph at 125 amps, 48v. With 600# batteries duration would be more like 30 minutes, though, not 3 hours. Maybe 600# of LI-ion batteries would hit your range goal.
>
> Good luck
>
> Denny Wolfe
> www.wolfEboats.com
>
> ----- Original Message -----
> From: nedfarinholt
> To: electricboats@yahoogroups.com
> Sent: Monday, July 19, 2010 3:55 PM
> Subject: [Electric Boats] hull design
>
>
>
> I am interested in building an electric runabout and would like help on hull design. Here are the basic requirements:
> Less than 30 feet in length, preferably 25'
> Strip hull construction
> Sufficient beam to accommodate two persons side by side, at least 3', prefer 4'
> Sufficient stability to handle a broach in 3' chop or powerboat wake.
> Prefer monohull.
> Cruising speed above 10 knots.
> Cruising duration 3 hours at 10 knots.
> Would like to accomplish the above with less than 600 lbs LA batteries.
>
> I understand the tradeoffs among battery chemistries, motor, and controller types.
> What I want help with is hull design. The trade offs between length to beam ratio, drafts, and hull geometry. I have purchased plans for 20 to 30 foot canoes and Atkin's Sergeant Faunce utility. By increasing the freeboard and decking the canoes, I think I can handle the open water, but my real issue is how much must I increase the L/B ratio to overcome the 1.3xsq rt of waterline? I would rather not go as far as the guy in the Wye Island marathon who used a 50' rowing scull!
>
> Any ideas or experience or can you refer me to some sites or literature. I have already scoured the web pretty thoroughly.
>