Dara wrote:

- I am very curious as to why you have recommended an arrangement of 4 : 3 sheeted battens between the upper and lower sheets.  Perhaps my newcomer ignorance, I thought that using our upper sheet spanning the top two battens would allow more control of the sail including its twist as opposed to the upper sheet spanning 4 battens.  

I've found that it's easy enough to get a straight leech with control of twist under full sail, but it's harder to get a good sail shape with two or more reefs. That's where the upper and lower sheets come in. Once there are one or two reefs in, the lower sheet is taken out of play, and you're sailing on the upper sheet only. In which case, if there are two anti-twist spans with the upper one linked to two parts of the sheet and the lower one linked to just one part of the sheet, it's acting like a sail with four sheeted battens,  and then you maintain better control of the twist as you reef deeply. If you have the upper sheet controlling only two battens, and the lower sheet controlling five battens, then the lower sheet remains in play for longer, and I think you get a situation with one, two or three reefs where the centre of the leech falls away, while the top and bottom of it are being pulled more strongly.

However, I rarely got the sheeting right first time, for the full range of sailing conditions. All boats are not the same in their sheeting needs. That's why I recommend doing a temporary arrangement at first, and trying out some alternatives, before drilling holes and fastening blocks down. Looking at the 3D drawing and the old double sheeting drawing, I'd be inclined to try double upper sheets on the upper four battens, and a single central sheet on the lower three battens, four the best possible control.

Dara,

It would be useful to see a photo of this deck area, to see what's possible in practical terms. Pending that, I think that you need an upper 3-part sheet controlling the upper four sheeted battens, and a lower 2-part sheet controlling the lower three sheeted battens; both lead to a single large ST winch via two clutches, or to two ST winches. There are some different possible arrangements of the sheet spans, which can be experimented with, but it would be a good start if you can get the deck block positions established. I would try fixing two single blocks for the upper sheet to the middle of a rope span between the two uprights of the davits, if they are strong enough, to improve the angle between sheet spans and mainsail leech. Making a temporary arrangement is always good, when there is doubt about what will work best, so a simple rope span tied to the davits would be the basis of my first trial attempt. The lower sheet can be to a single and becket deck block forward of the lazarette, in the position as drawn.