Radical new mini

[ancient kayaker]

Originally Posted by Collin

If you heeled your boat until the sail was perpendicular to the water, you'd have 0 lift pulling you upwind. If your sail is 90 degrees to the water, you have maximum lift.

If we took an airplane, flying level gives maximum lift from the wings. As we tilt the plane, the lift goes down until the plane is flying on its side and it falls from the sky because the wings are no longer producing lift in the direction we want.

Collin, I think we are talking about different things. In my post #46 I was addressing the rep of scows for poor upwind performance, and wondering if a typical scow was unable to heel sufficiently to reduce hydrodynamic drag. This might be true in light airs, but in heavy conditions where the buoyant bow would make a difference there would be no difficulty getting enough lift from the sail to heel it. Insufficient wind on the beam would only apply on a reach, so my question was poorly phrased.

Nonetheless, the sail of a boat close to the wind produces the maximum lift and minimum drag. Just like an aircraft wing, a sail’s lift is produced normal to its surface. Unfortunately, when close hauled most of the lift goes into heeling the boat not driving it along.

[waikikin]

Here's another take on a rule length boat http://www.shf.org.au/SmlBt/Skiffs/YendPop.html from 80 or so years ago, still in nice condition but too precious as an example to sail. A replica has been built & sails regular now http://www.youtube.com/watch?v=fGwtTyRy0pw

[Perm Stress]

Originally Posted by viking north

Yup and that i can see now that is exactly what is occuring. Wonder what that ride to windward is like, one imagines a bucking bronco but the video seems to show otherwise. Should have put more sail area on those old bluffed bow lifeboats and entered the Trans Atlantic

And powerful grinding machine to grind off some skin thickness to make it lighter .

By the way, traditional Dutch boats look absolutely terrible shape in plan view -almost square ends -but sail quite well, when heeled.
And do not go forward readily with powerful engines -because engine push them with no heel .

[viking north]

One was aluminium and I had no alum. welding capability at the time-- so prefabed the keel at a local machine shop with a fastening flange. Fastened it with something like 400 sealed headed 3/16 marine pop rivets bedded in 3m 5200 caulking --not one leak--sold on 3m 5200 after that. The other ya could have grinded off 1/4 inch of the skin and still had lots.
Maybe those old builders knew their hull technology better than we thought-- cods head and all -- but just didn't have the little extra info to pull it all together. ---All in all Very interesting --Maybe i'll change the orientation of my keel by 180 deg. and present the blunter end as the bow