Foils, Foiling & stuff..

There's a piece on foils and why the AC has the wind limit they do have on Sailing Anarchy

According to tonight's programme the AC72s weigh about 7 tons all-up, but the foils get loaded up to about double that during manoeuvres.

They do seem to have to work hard to keep the ride height stable, it must be especially difficult given that the rudder foil angle of attack is fixed. You can clearly seem them pitching bow down on the bear away as they accelerate and the rudder lift increases; and similarly waving their bows in the air when they round up at the leeward mark.

Also interesting to see what they are doing with the wing trim to have effects you wouldn't normally consider when sailing. Watching the other night Oracle seemed to have the new windward hull out of the water before they were even head to wind during their so called "roll tacks". I'm assuming they keep the wing over-rotated as they head up so it produces a windward heeling moment to pop the boat onto the inside hull, but they must have to be pretty smart getting it turned back again to stop it from capsizing the boat as they get onto the new tack!

Ah, I've met that guy, he has a workshop down at Weymouth that was almost a surface running foil as I recall, all in one thing, I've got a pic of it somewhere, too much drag I thought.

I was trying to get him to make me a set for a windsurfing race board, but the costs became prohibitive and it was around the time of lehmans when we all pretty much lost our mojo..

I wonder if he's still there, funny I was thinking of having a jolly down at speedweek with the Twin just to see what she'd top out at in her current form for a lark.

I so want to do this, it hurts, it's built for it I can vary the angle of the centreboard foil manually like those AC craft do, I could have one either side and twin rudders, it's got endless scope to be foiled.

Graeme

id like to see a moth try a c foil on the bottom of the vertical foil instead of the standard flat wing type.  has the self leveling and ability for veal heal.