Why so many differences in sail size designs?

Hi all. I need help, please.

Just got back from a transat crossing and my sails need to be replaced.
I'm looking to buy a new set of sails for my Elan Impression 514 and have been getting many quotes from different suppliers.

While I'm finally getting to grips with the differences in materials used and related performances and prices, I still can't understand why there are such discrepancies in the square meters that I got from each sailmaker. These range from 63m2 to 71m2. That's a huge difference so far as I'm concerned.
Same thing for vertical battens: Some propose 5 full + 4 short; others 3 full only; others 5 short ones; etc...

The Elan Impression 514 is at least 20 tons and any extra sail surface would be greatly appreciated. The problem is that the one sailmaker who can deliver the sails in time and at a good price is proposing 64 m² with 5 short vertical battens, whereas the boat was originally delivered with a 68 m² mainsail and five full vertical battens. I feel like I'm going to be losing performance.

My current conclusion is that the length and number of battens is what determines how much more roach the sail can have? Is there anything else that can impact the surface area of the sail? (everything else being equal, of course, i.e. same measurements, same fabric, same cut...). If I ask for longer battens, would this allow the sailmaker to increase the roach?

Can someone explain to me why there can be such differences or if size is determined by the design, number of battens, etc. -- assuming the same material and cut? These were given for laminate radial cut in-mast furling main (I= 18.99m; J= 5.48m; P = 18m; E= 6.65m) . Tks

 

Welcome to the forum.

You have it about right. The amount of roach you can carry, is tossing off the total area for the sail. Naturally, full length battens will permit different sail shapes, compared to short ones. This extra area is what you seeing, in the comparisons. Also, in regard to most sail plans, the area within the roach, unless excessive, usually isn't included in the total area for the sail, in as much as sail plan balance is concerned. Of course, this assumes typical shapes, not extreme roach and/or square tops. Lastly, some sail makers will provide the area, the sail plan suggests it should be, while others will provide the actual fabric area, which can swing off the figures comparatively.

 

others might be able to give you more specific information, but I can answer some general concepts:

the smaller sail areas will still perform well in at higher wind speeds, indeed likely better, but for that you will loose low end performance. the smaller sails should be lighter and I imagine costs less since there is less materals as well. the larger sails should have better light air performance, but it means you would have to reef sooner, have more weight aloft, and likely will be more work in handling it.

generally the more battens the better the performance, not just to get the larger roach, but also the battens help maintain a better shape of the sail surface to the wind. OTOH, most sail makers will tell you that the batten pockets are a constant source of wear and maintenance on the sail, so the more battens, the more areas on the surface that will need repairs and reinforcement.

As I see it, if you intend to do a lot of racing in all conditions, more and larger sails with lots of battens will give you an edge. If you intend to mostly do recreational sailing, than smaller sails with less battens would be a better choice.

Of course this all assumes the quality and the shape of the sails in all options are well designed and optimized for their size. A poorly cut sail, no matter the size, will not perform well in any conditions.

 

Thank you all for the valuable input.
How can I determine the size of a stabilizer sail for my boat? My sailmaker does not seem to know.
Tks

 

what is a Stabilizer sail used for? Not sure what you are asking.

 

Is this a steadying sail flown from the back stay?