Annie Hill wrote:

Jami Jokinen wrote:Actually I was hoping to be able to use batten length of 3000mm (because the al-tubes in Finland are sold as 6000mm). That would make some 2.2 or more, I suppose (SA of 24-25 sqm). This might be too optimistic, though. 

I don't suppose bamboo grows very well in Finland?

The problem with a high AR sail is that the upper parts of the sheet are pulling very strongly downwards, in the athwartships plane as well as the fore and aft plane, if you don't do something to improve the angle between sail and sheet. This pull has to be matched by an equally strong pull on the LHP, if the sail is not to set with distortion and creases.

This question of what is a satisfactory sheeting arrangement is very subjective. If you get three different sailors to try an anti-twist single sheet on a high AR sail, with the deck blocks on the centreline, you might get three different answers:

"It's fine, I'm happy with it"
"It's not perfect, but I can live with it"
"It's not good enough, I should try to find something better".

If you're really going for AR = 2.2, then I think you should start with an upper and a lower sheet, with the deck blocks central, and see what you think. Sheeting from the weather side always adds complication, and only you can decide whether that complication is justified by lower loads on the LHP and an easier sail to set.

Jami,

if it is the AR=2.10 rig in your album, that you are thinking of, then I think the Johanna-sheeting should be ok. You may not be able to sheet the furled bundle to the centre line, but you should be able to sheet a deeply-reefed sail for full close-hauled sailing.

Plan B, if the space is on the short side, is to have a separate upper lower sheet. Better that than a sheet track, in my opinion.

Arne

The Stellrechts' 'Flutterby' is in the upper reaches of aspect ratio and SA to Diplacement. While they were considering their sails' geometry, I remember, they looked forward to light-air goodness and reefing routinely for stronger breezes. I believe they're pleased... worth talking to them probably.

Cheers, Kurt

Richard Brooksby wrote:

Roughly what angle of sheet is too steep, in your experience(s)?

In the fore and aft plane, we can say that a minimum of 10 degrees between leech and upper shet is a reasonable figure, and of course, if the top sheeted batten is extended, this helps enormously.

In the athwartships plane, I would just say that the top  of a high sail really needs to sheeted to weather (however you do it), or you won't get full value in terms of windward ability from that height, and I would have to question the wisdom of making it so high.