The first clue I had suggesting that your analysis needs revision comes from the contributor to this forum wo said his I20(?) came up so quick the high daggerboard slid down into his harness, pinning him under the hull. Fortunately for the rest of us (not to mention him), he survived to write a warning.



Second, my dry weight, 150 lbs, is sufficient to raise my 5.0 on land. Without going to the end of the pole. I'm with Steve on the fire extinguisher thingy.



So I took a second look at your analysis, to see where it's... um.... imprecisely alligned with the real-world system.



For one thing, while the halfway point for mast length is maybe 16 ft, or 14 on mine, you know well that half the sail's area isn't halfway up the pole! I don't now how to do the math, but let's guess (gasp!) a third of the mast's height = 1/2 of the combined mast/sial weight. Certainly, the top third twists off and dumps the wet stuff much faster than the bottom, and the jib doesnt get above the middle third, or very little. Sure it's got moer moment, but there's so little of it... I dunno, I took a wild guess at a third.



Thus, heeling moment while flat over is 65 X 11 = 715 lbs. So 4 feet of pole should just do it for a 180# guy. Absent other considerations. And at 65X10=650, my 150 only needs to be a smidgen over 4 feet of pole out, and that's what I experienced. This in non-wind conditions; ie, no aero - righting, no wind on the tramp trying to turtle etc etc.



This suggest to me that it's dynamic factors at work here, like wind load, water weight, etc.



As for the rivets, I told Steve at Murray's the attachment plate was a near-infinite force multiplier for popping the rivets as soon as I opened my kit. HIs reply "Nobody's complained of any attachment failures, though the pole will knock off the striker and cause the occasional mast failure." I ignored his advice to just "rivet it on, you'll be fine" and built up a platform with epoxy, and used 4 rivets instead of 2.



Done the way Steve suggested it, the assembly has the same force multiple as a claw hammer pulling nails, and for precisely the same structural reasons. Except this claw's got a compound handle with a 6 foot long business end and rigging to put over a thousand lbs of force into the claw, which then applies a 200x multiplier of it's own. .



Pop go the rivets!



Murray's should admit their falw and suplly a curved plate to replace the current flat one. Monel rivets and an insulating sheet for galvanic protection wouldn't hurt either.