How about increasing the mast balance?
When I hoisted my first junk sail with barrel-cut camber in each panel on my Malena, no less than thirty years ago, I was quite worried that the mast would ruin the camber and performance on the port tack, so I kept the mast balance to a minimum, around 10-12%. Since it worked well for my use, I kept it like that. On my Johanna, a decade later, I was forced to haul the sail far aft to avoid lee helm, so her mast balance was set to the minimum possible (diagram below).
Only when Paul Thomson rigged his La Chica with over 20% balance, did I start thinking. In the spring 2021 Ketil Greve constructed a 35 sqm JR for his Boudicca, this time with 60° yard angle, and rigged it with 21-22% mast balance.
This very sail was copied this spring by Paul Schnabel, and he and his Toni now sail around with it set with about 25 % balance.
That rig has turned their Maxi 77, Ilvy into a pocket rocket, even with an extra half a ton of cruising gear on board. Paul reports about great performance to windward. Moreover, he tells that they can also reef the sail when running downwind, without any need for downhauls. That surely would not work with my low-balance sails on Johanna or even Ingeborg.
This new knowledge opens new possibilities. Below I let you see Johanna with the rig she used, and also Graham Cox’s boat, with a tentative large rig set with as much as 29% mast balance.
Now, if such a high-balance JR turns out to work well on both tacks to windward, it would be a much better rig for offshore work, so there would be less need for splitting the rig into a ketch or schooner configuration.
Look at the diagram of Johanna and Mehitabel running before towards you.
- · With the CE of Mehitabel much closer to the mast (than on Johanna’s rig), the steering bias would be much reduced when running before.
- · The sheeting forces would be reduced.
- · Possibly the battens would see lighter load - until S-bending sets in at the mast...
- · The centre of gravity (CG) of the sail would also be closer to the mast and this will result in less friction when hoisting or reefing the sail (..just as Paul S. reports...)
- · With the rig sitting closer to the centreline, there will be much better ‘heeling clearance’ (37°) as well. I dipped the clew of Johanna’s sail quite frequently, and although this did not appear to cause any stress, it was still a bit annoying.
Conclusion, so far:
If these high-balance sails (up to 30%, so far) do not show any snags in handling or performance, I think I will advocate the use of them, in particular on sails above 30sqm. On smaller sails for lighter boats, I guess I will still suggest using the 70-degree yard and max 17% balance, as these sails lets one have a bit bigger sail area on a shorter mast. Weight counts more on smaller boats.
Something to consider?
Arne
(..go to my album, Anes's sketches Section 7-46/47 for full size diagram...)