Rotating Keel

Hello,

On a monohull, if you make the keel to rotate under a monohull, when the boat leans by the wind pushing it over, if you could rotate the keel some in the direction it leans to, why won't it have an uprighting force for the monohull ?
The rotating keel angle may tend to push the mono hull sideways some but could well keep the boat more upright and even more speed may be possible.

The angle of rotation would be a function of the hull speed at that point and the angle it is leaning over. Yeah yeah I know keels are heavy, but hydraulics are wonderfull things too.

If this works then a monohull could probably get away with less weight in the keel as well. Maybe someone tried this before ?

 

It's called a canting keel.

Pericles

 

Ok, I didn't know they existed. Any advantage on them ?

 

Guess so. They set the fastest times. Here is Wild Oats:
http://wwos.ninemsn.com.au/article.aspx?id=317301
About 12 seconds into the clip you can see the keel tilted to windward. She went on to win for the third time in a row.

It enables the boat to have a righting moment without any heel so they can keep sails upright and hull level. The main benefit is that sailing monohulls is now more suited to average people who have both legs the same length. Before cats and tris were invented average people had no way to enjoy sailing. Now they can choose any type without need for the lopsided leg surgery.

Rick W.

 

Well considering the 24 hour record in a monohull is set in a canter, I would think that there is some certain advantage to having a canting keel.

TC

 

And on occasion, they drop off.

Pericles

 

Average people don't sail these boats.

TC

 

I was wondering why the mono-hullers don't have v-ed decks for the people with equally long legs... you can stand upright on the one side and when you tack you stand on the other wall I mean halve of the deck...

I must admit I was never interested in sailing until I've seen some multi-hulls.

 

Remember all non Aussies, The Syd/hobart ritual is restricted to monohulls - they don't want to be embarrassed by cruising multi's, let alone the racing ones in the 'round globe etc........

 

Fanie
The helmsman's position on the larger yachts often have a curved deck for exactly that reason.

Rick W.

 

I have a boat with a "rotating keel" (well I choose to call it that, others may choose to call it a propellor.) Like the Sydney - Hobart boats the keel is driven by a motor that runs whenever the boat is underway. My boat can go much faster than the Sydney - Hobart boats though. If I could improve the "sailing" range I think it could give all those supermaxi's a real run for their money.

Of course it's not really a sailboat, but then that's not a requirement anymore is it?

 

How embarrassed would they be? VERY embarrassed. : http://au.youtube.com/watch?v=k90uvFENVcY