I have a Hirondelle catamaran fitted with an Aerorig, which was a commercial carbon fibre ballestron rig.
The ballestron is allowed to rock in a vertical direction a small amount and is only lightly restrained from twisting round the rotating mast. This is done by two raised rectangles with semi-circular bottoms on the mast and two matching cutouts on the part of the boom that surrounds the mast. As the mainsail is raised, the boom is aligned by the above keys.
There is a topping lift which is connected to the end of the boom when the mainsail is lowered. It seems that the mainsail tension is enough to keep the fractional jib foil straight.
The ballestron boom is rectangular, tapering in the vertical direction away from the mast (i.e. thickest at the mast).
I would say that it is an excellent rig for singlehanding, and is especially worry free when the wind is aft, being like an inverted square sail; you can sail by the lee by letting the boom go forward a bit, and there's never any chafe.
For a slightly different approach, see http://www.freewing
regards
Nuvaslacker
--- In harryproa@yahoogrou
>
> Any words on vangs? I realise it will be free to bend in the unconstrainmed direction, - I guess this is heading towards the Wishbone style that was on harrigami, or was that just loaads of ropes but not really stays?
> Even if the booms were stayed in both dimensions that could make it plenty stiff..
>
> Rob, are you inthe Sydney to Hobart this year?
> Or is Rare Bird?
>
> Doug
>