Rob answered this quite succinctly in a mail some time ago. I paraphrase: if you want a light boat for its length then a proa is the preferred choice; if you want some more load then a catamaran makes the most sense; if you want to pile it on go for a monohull.
The Kelsall proa would fit your specs. It is of the second kind but retains hulls that are somewhat unequal in length and are bidirectional. I suppose it would ease the build to have equal hulls and it is only a small step to make them unidirectional and eliminate the complication in the rudders.
Luc
--- In harryproa@yahoogroups.com.au, gardner@... wrote:
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> I think I have asked this before, but I can't locate the response and I keep coming back to it.
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> The harryproa model seems perfect for racing and for cruising with 1 or two bunks, but once you go past that, it seems that you have to start adding things to the leeward hull. When the lw hull starts having accomodations, I wonder what the real advantage of a proa is.
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> The more I follow Rob's developments, the more I am impressed with his build techniques. I know they originated with the weight to windward proa concept, but they would seem to have much broader applicability.
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> As an example, I did a quick sketch of a 40x24' catamaran 4 double bunks, using simple hulls like used on the newer harrys. I then added kickup rudders, similar to the newest Solitarry, but not speer sections. Combine that with freestanding masts, either in a biplane rig or even centered on the beam if Rob's telescoping idea works out. This looks like a very simple to build and lightweight catamaran. The total surface area ended up at about 3000 sq ft.
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> I am trying to understand why this isn't a good idea (for bigger boats). Are there more racking forces that make a significant difference? By eliminating the standing rigging, the vertical load on the crossbeams has gone away. Do the simple hulls not work for a catamaran?
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> - Gardner
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