The failure to see how a relative single narrow hull proa would drive with less effort through the water vs two hull is where the confusion always starts.

Besides being heavier over all with two large volume/displacement / structure surface areas with weight and accommodations to windward.
length for length the two different types would require different sail areas to drive each through the water for a set speed. I don't agree with the one with more weight to windward would be faster or be more forgiving safer. I have explained why before here's another take of an advantage involved. It could be used on either craft regardless

To me over turning/heeling moment is not only in sail area vs weight to windward or any type of weight there abouts. Sure weight is an issue but so too is the effort required for hulls to move forward through the water with least amount of impact on forward drive! The sails ability to maintain forward drive with out excessive heeling force is also crusial. Sail/s draft stability in all trim angles. Hard to do with a soft sail. Unless its a kitesurf kite. Anyone that has used post 2002 kitesurfing four/5 line kites know that by leting go of the bar the wing sheets out its trailing edge. Thus flying off front lines with a forward draft and center of gravity stable position. To gain in power the bar is eased back progressively depending on wind strengths. It doesn't need to be reshaped for forward drive Thus in light winds pull back bar to far and kite shift its draft aft and flys backwards. Revolution kites have the fastest reverse speeds of all the kites. They fly almost as fast back wards as they do foward. Hows this realate to Sails on a sail boat or proa for that matter. The traditional western style sails can't match the draft stability and ease of control ability like that of the kite. But the solid wing can!!! Very same principal as kite, with its more precise draft control with angle of attack (not sail shape), with out losing forward drive to over turning moment for the widest wind range possible for any given point of sail. Forward maximum drive in all sheet angles for widest wind range possible.

Todd

I no most will think its hog wash but what the hell its there plan as day. Sounding like a broken record, if I only had the money!!!

How do you get forward drive with out excessive heeling moment with least amount of hull drag from western traditional rigs? With a forward set sail/s CoE!!!

--- In harryproa@yahoogroups.com.au, "John" <jrwells2007@...> wrote:
>
> With the rig in the ww hull you have the type of stresses that are found with a trimaran.
> With a Harryproa the beams take the stress of the leverage of the mass of the ww hull plus the drag of the windward through the water and air.
> A pacific proa setup has the leverage of the ww hull plus the drag of the lw hull that becomes greater as the ww hull lifts. Eventually as the ww hull comes out of the water the full drive pushing the proa along goes via the beams whereas with a Harryproa this drive does not stress the beams.
> I would have thought that the pacific proa has to be able to cope with greater stress in the beams than the Harryproa.
>
> --- In harryproa@yahoogroups.com.au, Doug Haines <doha720@> wrote:
> >
> > Hi Dennis and Rob and all,
> >
> > I am looking at Dennis's Maxi trailer 60'er a bit more and see how this could be a better design with the rig in the ww hull.
> > Secondly I am not sure, but it seems that there is going to be less stress on the beams if you have the sails on the hull that is getting lifted up. Instead of the sails over on lw hull.
> > This is intuitive - I have to mull over a bit on that, but i think the hull and beams will see less loadwhen the wind starts to push the ww hull up out of the waater. It seems an even simpler way of sailing than standard HP - if that was possible.
> >
> > The down side is having to look up at your sails. I don't know what other changes it would mean.
> >
> > Doug
> >
> > --- On Tue, 28/12/10, Dennis Cox <dec720@> wrote:
> >
>