Retort in reverse to Robs post.
When I usually ask for help I usually get a very general or vague answer.I stopped asking for help along time ago. I agree the beam thing is complicated but in theory my general statement still stands and you have yet to prove it wrong.
I said I don;t see how or why Robs beams would be any lighter than a pacific or a Atlantic. I would add that even if they where the significance would be nominal over what Robs Lends it to be. Tetter- totter ever play on one? The balanced beam weight plays very little roll It just needs to be strong enough to support weight at each end.
Luck had everything to do with it. Good thing more bulkheads didn't pop or worse yet have the hull tear when the bulk head popped.
Read your own post and for an example the latest one by another poster. Misrepresentation in communication turns into who can win an argument vs truth. Chess game really.
>Nothing has been said here making holy grail claims; only that a >weight-to-windward proa with a lee sail is a way of creating lower >stresses than most other designs. Don't agree? Fine.
Nothing against you Mike. But Holey grail was a In reference to Robs holding back on beam wall thickness tapering due to his assumption of my knowledge again. What he thinks I don't know! Trying to win his argument on deception vs truth.
If Rob you are referencing that your beams are lighter due to your boat having the middle platform that also is a support structure between hulls making your conventional beams lighter than need be. I'd agree, possibly.
--- In harryproa@yahoogroups.com.au, Rob Denney <harryproa@...> wrote:
>
> On Mon, Nov 15, 2010 at 4:02 AM, tsstproa <bitme1234@...> wrote:
>
> >
> >
> > I can see better now where your confusion has set in, at last once again.
> >
>
> Good for you, perhaps you could enlighten us.
>
> >
> > Nice, can't wait to hear what happens in a sea way couple 1,000 miles away
> > from shore. Just a popped bulkhead maybe they got lucky this time.
> >
>
> The bulkhead popped after 3 days in 45 knots plus. It was not built
> according to the plans, so luck did not have anything to do with it.
>
> >
> > Does your boat float when filled to interior capacity with water?
> >
> Not only floats, but could be sailed. As the hulls are each divided into 7
> watertight compartments , it would be pretty hard to fill it to capacity
> without using a hose.
>
> >
> > I ask for the general thickness from the beam you presented After I gave an
> > example of a 17' hollow fiberglass 8''x8'' beam with a 1/2 '' wall
> > thickness.
> >
> > Multiple thickness lay ups wooo whoooo whats new! like its a holy grail or
> > something when you could have just generalized...
> >
> Nobody said it was new. You said yours was lighter than "Rob's boat", I
> pointed out that you were mistaken. General thickness varies from 1.6mm to
> 12 mm. Hope this helps, but can't see how it will.
>
> rob
>
> >
> > Todd
> >
> > --- In harryproa@yahoogroups.com.au <harryproa%40yahoogroups.com.au>, Rob
> > Denney <harryproa@> wrote:
> > >
> > > On Sun, Nov 14, 2010 at 4:27 AM, tsstproa <bitme1234@> wrote:
> > >
> > > > Center of gravity and buoyancy. The more I can keep it that way the
> > >more it will resist heeling.
> > >
> > > This is meaningless.
> > >
> > > >Buoyancy along with a light weight craft the beams could be over built
> > >and still not effect the the intended use of design.
> > >
> > > The discussion was about harrys vs Atlantics and one mast vs two. The
> > > harry beams will always be lighter.
> > >
> > > >
> > > > Assume just one force to prove one point doesn't make sense.
> > >
> > > Maybe, but unless and until you grasp this point, further discussion
> > > is not going to achieve anything.
> > > >
> > > > So for your beams , your saying due to having a ww60/40lw displacement
> > and having an unstayed mast your beams can be built lighter than a pacific
> > or atlantic type using the same construction method being engineered for the
> > specific use on each craft.
> > >
> > > Assuming the mast is mounted in a hull, the overall boat weights are
> > > the same and it is a responsible design, the beams on a 60/40 proa
> > > will be the same as the beams on a 40/60 proa. They will be heavier
> > > than the beams on a 50/50 and lighter than the beams on a 70/30, a
> > > 30/70, a 20/80 or an 80/20, etc etc. The upper limit is if the
> > > windward hull is so small that it is submerged before the boat
> > > capsizes.
> > > >
> > > > You want me to pay 500.$ for what?
> > >
> > > I don't want you to pay for anything. You asked for the laminate of
> > > my beams. I told you it would cost you $500.
> > >
> > > rob
> > > >
> > > > Todd
> > > >
> > > > --- In harryproa@yahoogroups.com.au <harryproa%40yahoogroups.com.au>,
> > Rob Denney <harryproa@> wrote:
> > > >
> > > > > I don't understand your final paragraph. Or see what it or the video
> > has to
> > > > > do with this discussion. No idea what walla is, nor how it proves
> > that
> > > > > buoyancy to leeward of the mast makes a boat more stable, apart from
> > the
> > > > > added righting moment from the mast weight. Assuming the force on the
> > sail
> > > > > acts horizontally through the coe (and ignoring the rig weight), it
> > makes no
> > > > > difference to the force required to fly a hull where the mast is
> > located
> > > > > across the boat. Maybe your rig is a greater component of the
> > righting
> > > > > moment than it would be on a full size boat? Again, draw a picture
> > (or try
> > > > > to unbalance a chair by pushing or pulling it sideways) and this will
> > be
> > > > > obvious.
> > > >
> > > >
> > >
> >
> >
> >
>