Stavanger, Wed.
That sling-point
David and Peter
I have found that getting the sling-point right is important, and not always easy. On the more high AR sails like those on the schooner Samson or my little Broremann (AR=2.15) it is no problem. Here the sail goes up and comes down perfectly and will also accept a bit tug in the sheets while hoisting.
Not so on Johanna and Edmond Dantes (AR=1.87). On low AR sails the CG of the sail generally sits further aft of the mast top, angle-wise.
The dilemma is like this (I think):
If I fit the sling-point aft of the middle of the yard, Johana’s fanned-top sail goes up very nicely by lifting the peak and fanning up the top section first. However, when the sail is fully up, even on the 70° yard the halyard will point a lot aft with the sail fully hoisted. When I start dropping the sail, this halyard angle will lead to about 25cm forward movement of the sail at the first reef. This I have compensated for by cutting Johanna’s and ED’s sail 25cm short at the clew. However, if the sling point is set too far aft, the sail will continue to move forward as next panel(s) comes down until the halyard goes vertical or the batten parrels limits the movement (..forget about the maths of batten stagger in PJR - it doesn’t work like that with fully cambered panels...)
If we on the other hand fit the sling-point forward of the middle, at some point the throat will lift first instead of the peak. This not only looks bad, but may even get you in trouble with the peak falling inside the lazyjacks. This is particularly problematic if it happens while lowering the sail.
In both cases of sling-point positioning the situation can be kept under control with a light tug on the throat parrel, but that calls for another hand and is very awkward when hoisting the sail.
(..on Johanna and ED the masts are a bit too short and this adds to the fun...)
The trick is to fit the sling-point just far enough aft to avoid a "tailheavy" sail. This will hopefully lead to an acceptably low friction from the batten parrels, moderate negative batten stagger when reefing (only with the first reef) and lets one drop the sail quickly without needing to use the throat hauling parrel.
I think I have achieved that delicate balance in Johanna’s sail. In practice when hoisting and lowering her sail, I take care to have slack sheets. Only when the throat h. parrel and yard h. parrel have been set up,(after hoisting) do I touch the sheets. When furling the sail, I mostly do it in the middle of a tack, just as the sheets go slack.
I guess I could reef downwind with the sail working (auto-pilot or a crew needed) by easing the halyard and by keeping the sail peaked up with the throat hauling parrel, but for my inshore sailing I rather let go the tiller, and when the sheets go slack, I drop the panel quickly, adjust the parrels and then grab the tiller again.
Arne
PS: Some of this may be useful on the low AR fanned sails too, so be prepared to do a bit moving of the sling-point until you get it right. As little as 10cm may make the difference.
PPS: Peter, could i suggest that you use a rope sling at first and save the drilling until you have got it right?