Sail shape test (REVISED)
Hi guys (and ladies)!
Check out this great shot of the mainsail from one of the Volvo 70's.
If you look at the top, middle, and bottom draft stripes, you should be able to have a graphic view of what I have talked so much about; the location of maximum draft as a function of the chord length (from the luff to the leech).
You can (hopefully) see that at the lower stripe, the draft is fwd of the middle (good) and at the middle stripe this is reversed (bad), and the max draft is aft of midpoint, or close to it. The top stripe is back to"normal". The upper leech is very open, indicating lots of "twist", meaning the traveller is not all the way down, and the sheet is slightly eased-this is fast in chop, and is an intermediate depowering technique.
This is a sail that has been pushed halfway around the world and is due for replacement...It is, however, possible to improve this via changing running back tension (adding) to make the top of the sail fuller, and also by dropping the jib lead back to reduce backwinding-which is often the cause of this look and can be deceptive in that you may not really have a sail or rig tune problem-just a bad lead on on the jib...
Please feel free to post away!!!
Cheers
Hi guys (and ladies)!
Check out this great shot of the mainsail from one of the Volvo 70's.
If you look at the top, middle, and bottom draft stripes, you should be able to have a graphic view of what I have talked so much about; the location of maximum draft as a function of the chord length (from the luff to the leech).
You can (hopefully) see that at the lower stripe, the draft is fwd of the middle (good) and at the middle stripe this is reversed (bad), and the max draft is aft of midpoint, or close to it. The top stripe is back to"normal". The upper leech is very open, indicating lots of "twist", meaning the traveller is not all the way down, and the sheet is slightly eased-this is fast in chop, and is an intermediate depowering technique.
This is a sail that has been pushed halfway around the world and is due for replacement...It is, however, possible to improve this via changing running back tension (adding) to make the top of the sail fuller, and also by dropping the jib lead back to reduce backwinding-which is often the cause of this look and can be deceptive in that you may not really have a sail or rig tune problem-just a bad lead on on the jib...
Please feel free to post away!!!
Cheers
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