David wrote:
Arne,
My point is that they seem to be proof against F-U without anything to hold the top down.
I have halyard, sheet, YHP, LHP. A lower LHP is optional, as it is on H-M sails, but helps with keeping the luff taut when deep reefed. Again, it's something that inshore sailors may not need. Most of the time, it's redundant. A spanned downhaul is as good at doing that, and I may change back.
I agree, some camber in the panels helps to keep the leech from fluttering. That's one reason why I put some in, as well as hinges.
David, it could be that I as an inshore sailor don't know so much about this, but I doubt it. You know, there is inshore and there is 'inshore'. The fjords I sail may be protected from the swell from the North Sea, so very few people get seasick here. Still, the fetch can soon reach 10 N-miles or more, which is enough to develop a nasty, steep chop, big enough to provoke quite wild, rhythmic hoppy-horsing, even in just F4-F5 winds. Still, I have never felt any need for lower LHP. When I had hinged battens in Malena’s flat sail, I kept the original LHP over three battens in addition to the new THP that I then added, but I can’t remember why.
I think the HK-parrels help the lower part of the cambered panel sail from sawing back and forth on the mast when pitching. The top section has already been locked in its position, and can go nowhere. In addition, the luff from throat to tack is much shorter on Ingeborg's sail than on Weaverbird, only 4.86m versus 6.07m. In other words, there is much shorter length of luff to support, so I get away with the THP plus HKP.
Btw, from the top of F5 (offshore or inshore), the three lowest panels will already be nesting quietly in the lazyjacks, so no need for any lower LHP then.
I guess we end up with the same number of lines to tend. The new FUP line I have fitted may add a bit hassle, but I gladly live with that. It pays back in safely letting me rig that lovely, efficient, high-peaking, three-panel top section.
Arne
PS: As long as we both are happy with our rigs, there is no need to worry.