On Sat, Nov 20, 2010 at 11:39 AM, tsstproa <bitme1234@yahoo.com> wrote:

The weight of the rig is marginal over all especially for a stay rig.

On Solitarry, the rig weight is about 100 kgs.  Significant in a 700
kg boat.  On Visionarry, it is close to 250 kgs, significant on a 2.5
tonne boat.  A stayed mast would be lighter, but the rest of the boat
would be heavier.

Pacific proa the ama sinks to compensate its not held up by the same amount of buoyancy so there is a margine for play there as well. Even if beams were built to the what ever standard you guys are using the pacific would still be lighter over all even with the overly built beams.

If ama sinks on pacific why would hull lift out of water and if the Pacific were to fly leeward >hull when back winded(Not even likely)if it did wouldn't your torsion load pivot hull back into >water nose down back onto LW HULL, being as the leeward hull the heavier of the two.

Sounds to me you all believe alot of here say!!!

How many on here have ever sailed a pacific style proa?

Many of us, including me, but it is not really relevant,.  As a
conscientious designer, you have to design for the worst case
scenario.  If you want a boat where the beams can break in an unlikely
but possible scenario, that is your call.

A windward hull small enough to sink on a caught aback cruising
Pacific proa would be very small.

Rob

Todd

--- In harryproa@yahoogroups.com.au, "John" <jrwells2007@...> wrote:

- "What I still don't get is Rob saying there is no way beams on an Atlantic or Pacific would be lighter than on his craft due to lower forces at play. To me it still seams its based on weight, and where it is located."

Take a simplified aspect of weight and where it is located.

In an Atlantic proa the windward hull will weigh at least the same as on a Harryproa plus the weight of the rig. When the forces on the sail are sufficient to lift the windward hull out of the water, the greater weight of the Atlantic configuration will put greater stress on the beams than for the Harryproa. This is ignoring the greater stress due to torsion loads.

In the Pacific proa configuration, when it is caught aback you have a similar situation as the Atlantic proa - accommodation-hull weight plus rig weight being lifted out of the water. Although some Pacific proas may never be caught aback in high winds, the beam strength required needs to assume that this might happen on safety grounds especially offshore.

In both Atlantic and Pacific proa configurations the beams will need to be sized for worst case scenario - hull being lifted out of the water.

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