there's nothing wrong with wanting to eat your cake and have it too!
i've posted files of the "tilting" pantograph idea to the yahoo proa group. if anyone here is interested and not also on that list, let me know and i can cross post.
ben
--- In harryproa@yahoogroups.com.au, Mike Crawford <mcrawf@...> wrote:
>
> Ben,
>
> I hear what you're saying. Not only do you want the benefits of a
> proa, you want the benefits of a non-proa, too. Fair enough. I don't
> judge this because I want the same thing. I won't get 100% of it, but
> that's no reason to not aim high.
>
> But for the sake of discussion, I'll play devil's advocate with
> regards to weight aft.
>
> ---
>
> When compared to an equivalent trimaran in terms of weight and price,
> the proa is going to have a longer leeward hull. Yes, there will be
> more bow-down trim than if you move everyone to the transom, but all
> that extra waterline length will mean a lot.
>
> Take a Corsair F31, at 3,800 pounds, with a waterline length of 30',
> for $140k. If you go with flat-panel construction, you could easily
> build a 50' stretched Harry (halfway between the Harry and the
> Visionarry) with a lower weight and lower cost.
>
> When the weather gets rough, or when pushing the boat in a race, I'd
> rather be on that 50' Harry than on the 31' Corsair with my crew in back.
>
> Particularly because the Harry can be made with long, wave-piercing
> bows that that easily shed water. They'll be much more likely to slice
> through a wave, or bury and then rise gracefully, than the Corsair's
> main hull. No amount of weight aft is going to solve the problem of
> burying non-wave-piercing bows after surfing down a long wave face.
>
> And since the proa bows are so far out in front of the windward hull
> bows, the boat will be less likely to trip over them.
>
> Finally, with the right design, hydrodynamic lift will help with
> keeping the bow up, or at least not down as much as it otherwise would be.
>
> ---
>
> So I'd say weight location is an issue, but a secondary one given the
> design.
>
> Of course, you could always build a proa with splayed beams, like the
> Expeditionarry or the Wantoo, and put crew further aft that way.
>
> That said, I look forward to your new idea for shifting weight. If we
> can have a long waterline *and* be able to easily shift weight, so much
> the better.
>
> - Mike