look at firefly. the forestay and backstay are well inside the overhangs to avoid this twisting ( or thats what makes sense to me ). the loads while broadreaching / running are nothing compared to closehauled but then again firefly is only 60tons compared with 178.
Clear ! I guess it all comes down to designers and engineers designing to the forces they expect a part/section of the boat to be submitted to.
When new techniques bring these forces well over what had been originally expected .... shapes and engineering are challenged, and on the Js one can improve engineering but geometry is here to stay.
Looking at day 1 of the Solent cup, I doubt the pre WW II J's would have raced and/or sailed under full sail; strong chances masts could have tumbled down, too.
OK moody but even with stronger new sails, with the same stiff keel, forces will be about the same on the hull because, the only difference ll be the boat to heel some more, no ? No stiffer Class J boat , no problem with new forces no ?
As far as i understand it, if, previously, part of the power imposed on the rig dissipated through sails "bagging and opening" and/or mast leeward bend, the ultimate forces transmitted to the hull via the rigging stalled at a given limit.
These boats have a huge RM and now, with stiffer/stronger masts & rigging + stiffer sails, transmitted forces can only increase and while the lead copes with it, the next weaker link (between wind-force and lead-keel) has to reach its deformation point.
Dirty is, of course, right: these old boats have been enormously improved, designers did extensive and sophisticated work on figures and loads. Now my questioning which goes beyond Js is the increase in loads just by going from 3DL to 3DI. I was guessing that Js RM was somehow quite exceptional and that % differences may show more clearly. Just armchair reflexion I guess.