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Old 03-07-2007, 05:24   #1
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Dealing with Wind Shifts

DEALING WITH WIND SHIFTS

HEADERS:
When the wind changes to a direction more to the bow of the boat it is called a header. A header will usually cause the sails to luff. You can do either of two things to adjust for a header. One is to bear away until the boat has the original wind angle again. The other is to trim the sheets so that the sails are correct for the closer wind angle. If you are already sailing close hauled when you get a header, you can't trim any more. In this case, you can either bear away or come about.

LIFTS:
When the wind shifts to a direction away from the bow, it is called a lift. When a lift happens, the sails will become over trimmed for the new wind angle. An over trimmed situation is more difficult to detect than a luffing situation. The way to be ready for a lift is by keeping an eye on the telltales so if a lift does occur, you will notice the change. You can adjust for a lift either by easing the sheets or by heading the boat up to meet the new wind angle. If you're not sure whether a lift has occurred, try easing the sheets anyway. When they are out too far, the sails will begin to luff. Then you can pull them back in to stop the luffing. Lifts are beneficial when you are beating to windward. They enable you to change your course to a direction closer to your destination.

How to Sail Fast Up the First Beat When You Have Oscillating Shifts
by David Dellenbaugh
How to Sail Fast Up the First Beat When You Have Oscillating Shifts

There is lot to can gain from wind shifts
There is a lot to gain from wind shifts in sail racing

Playing the Shifts ~ by Ron Sherry
http://www.sailtoronto.com/racetrain...yingshifts.pdf
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Old 03-07-2007, 10:26   #2
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this is great info, thanks!
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Old 03-07-2007, 11:47   #3
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Question:

Does "lift" refer to the telltails getting blown up as the sail tries to stall?

I'm trying to gather what happens to the boat in each case... first time I've heard these terms.
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Old 03-07-2007, 12:40   #4
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Aloha Zach,
I believe lift refers to lifting you upwind and more toward your upwind destination. Headers head you away and lifts lift you toward.
JohnL
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Old 03-07-2007, 12:52   #5
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Lift That Barge, Tote That Bale

Hey, Zach, good to see you out there.

Since you're pleading complete ignorance of the term, I'll throw in a quick mini-lesson:

Three, yes, three, different kinds of lift! You're really getting your money's worth for your question.
  1. There is the hydrodynamic lift that is created on the windward surface of the keel, just as lift is created on the upper surface of an airplane wing, which "sucks" the keel to windward when under way and fights leeward drift, illustrated by this diagram. You have to imagine looking up from under the boat: I find that holding my breath helps.
  2. There is also aerodynamic lift, created when the wind passes over the outer surface of the sail, also shown in the diagram.


Now more to your question: why the wind shift itself is called a lift.
I'm just taking a stab here, and could very well be schooled by someone who knows, but the word lift seems to me to refer to the ability to "lift" (or point "higher") the bow of the boat as a result of the wind shift, and so, like the term "point higher," is being used metaphorically, not literally (nothing is actually going up or is higher than before. I imagine the term was brought into use without reference to tell-tales, but I don't know how old or universally-used tell-tales are/have been. I'll be happy to be clobbered on this one.

How are your plans going? Would love an update.
Jeff

I was typing while John posted: he says what I say, but more economically.
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Old 03-07-2007, 16:49   #6
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Quote:
Originally Posted by Zach
Question:

Does "lift" refer to the telltails getting blown up as the sail tries to stall?

I'm trying to gather what happens to the boat in each case... first time I've heard these terms.
No, the telltales will rise when you are "headed". A "lift" will actually cause the telltales to fall.
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Old 03-07-2007, 16:53   #7
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Inside woolies flutter- pull tiller in
Outside woolies flutter- push tiller out (away from you).

My wife can't get used to the wheel though!
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Old 03-07-2007, 17:26   #8
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Seafox - If you're sitting on the windward side.
Regards,
JohnL
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Old 03-07-2007, 18:29   #9
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Just as an aside, there are 2 sorts of lifts: direction lifts and pressure lifts. The direction lift (or, indeed knock) is caused by a change in the wind direction, whereas a pressure lift (or knock) is caused by an increase (or decrease) in wind strenght. Bascially, you as wind strength increases you can "point higher" i.e. sail closer to the wind
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Old 03-07-2007, 19:32   #10
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The best way to learn about wind shifts is in a dingy. A small boat catches any changes faster and will telegraph them through the tiller, angle of heel, and I also seem to feel the breeze on my cheek better. Even better, race in a dingy, have fun.
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Old 04-07-2007, 14:52   #11
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Cool!

Thanks for the lesson.
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