Jamie Wrote:

The answer is 2 fold:

1. Apply backside mast rotation control at the front beam to prevent the mast from over-rotating in these conditions.

2. Add a little more downhaul to give the mast more support down the back preventing inversion.

Hi Jamie, we've met before, when I was over Forida's way for some regatta's so time ago.

I never analyzed the forces in my masts inversion, always chocked it up to alot of double trap, in conditions like you state, and alot of chute flying, metal fatigue, (my sail used alot was #111), etc.

Interesting your statement about the backside, or leeward rotation on to prevent over max rotations. The double trap scenario also acts as a rotary force, further overrotating the mast. As stated, I increased spreader rake, and wire tensions, after manually bending the bast back from inversion-(waht a chore that was!), and even with the chute, etc, sails great again.

I agree totally with your analysis, and measures to prevent it's occurrence. I now always use some degree of downhaul, even when it's light, and always keep the main sheeting tight with the chute up, using traveler if needed. I'll definitely be trying the leeward side rotation prevention as well.

Todd Bouton
N6.0na, +
#111