i think we should walk/talk more conservatively; any error in calcs; could multiply on the next error, a string of these errors/assumptions would not put us where we claim to be.
When did rope strength /synthetics requirement drop to 5000?
Is a line wrapped around, rubbing itself (as basket doesn't do) still the same as basket strength?
Samson told me that it wasn't as strong as 2 lines (rope slung over support to hitch load in basket lacing); that they calculate strength in that position at 1.65x tensile not 2x. Saying that the round sling qoted as 2x has more legs, and that is more of a convention to quote 2x, than science.
if we wrap a 5/16" line around anything, wouldn't we still want at least 4x diameter for the host it constricts; which would be over 1"; really to quote at 100%; host should be 8x diameter; and some chords might be a lil'stiff for that general formulae?
So what is the compounding mistake of all these 'errors'?
Everything is being assumed at full strength; yet is prolly comrpomised here and there.
Taking 1/2 of the metal strength; assuming full basket strength even though baskets don't bend over themselves rubbing, assuming a line as a roundsling will be calculated at 2x strength assuming no loss from bend: all could have compounding error; on perhaps the piece taking the most friction?
i'm not saying that they aren't safe, just that a publically proclaimed 2500# isn't conservative/high enough to say that you are staying with the whole rest of the philosophy of SWL; in the smallest, thinnest, newest piece of synthetic gear we may have; that might take the most friction abuse in the smallest area. i think that (at least publically quoted) shold be more towards 3500-4000; why not? Brian's chord recomendation hits that,and is smaller diameter, so could retain more strength wrapping around a 1/2" host.
i believe as Bradley does, that descending on a hitch tests it more than sitting ascending. True sit/ascend has to grip harder and hold so muenter though a descending hitch, and up to those riggers, is not good enuff for the sit/ascend; but i general if it can take the rigors of descending is the true strength and sturdy test to me.
i think that a system is as strong as it's weakest link; if we will cut corners here, why not lower the strength of the whole system?
i think for a lot of non-JP type climbers; the SWL ratio for lifeline gear ends up closer to 20/1. Even though the arguement can be made chord is a temp; i think we should maintain/raise/lower the standards in a planned way across the board.
