Subject: Re: [harryproa] Timber spar
From: "Rob Denney" <>
Date: 2/24/2008, 6:27 AM


It will be heavier, possibly more expensive and will either bend more or be a bigger section than a carbon one, but none of these are deal breakers if you want a wooden stick.  Take lots of pictures and let us know how it goes.  Compare the righting moment of the Bolger with the proa to be sure you are in the right ball park.



On Sun, Feb 24, 2008 at 2:59 PM, proaconstrictor <> wrote:

I was wondering if any have given any further thought to a timber
spar. Don't freak, I know the carbon spar business is in need of
support. and that the carbon spar is the key to the whole design for
90% of the people contenplating this design. I was just thinking of an
unstayed Bolger spar I have the scantlings for, and it uses an
interesting constrution where the back of the spar is solid timber
boards and the front section is light plywood. The rig was something
like a lug or just a leg o mutton where the loads would pull forward on
the spar in a single direction. It occured to me that a similar thing
might be feasible on the aero rig since the spar rotates and the loads
could thus be kept in line with the heavier section. Not sure what
this would be useful for, possibly the original idea of a low
resistance cruiser of low cost. It would presumably just be an interim
rig until some time had passed and experience piled up and a move to a
better rig could be arranged.

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