Boom Vangs and loose foot mains?
- Thread starter neilmcc
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The primary mainsail sail trim control for TWIST is the boom vang (mainsheet is scecondary) and the boom vang doesn't care if the main is bolt rope or loose footed. The other sail trim controls for the main --- outhaul, traveler, halyard/Cunningham, mainsheet and mast bend --- don't care either.
I race on a Hunter 336 Legend so knew the boat pretty well.
When the wind piped up, you'll ease the vang to spill air on the top part of the main sail. Thus keep the boat on her feet. When the heeling is under control, the vang should be harden to close the top of the main and get more power (speed).
When the boat heel too much (>25 degrees), it is actually slower because of side way slippage and less sail area expose to the wind.
If you have solid vang, then no need to mess with topping lift.
On a down wind, you'll harden the vang to help the main capture more air. It also help keep the main off the spreader. Hunter uses B&R rig, you can't swing the boom out more than 60 degrees.
When the wind piped up, you'll ease the vang to spill air on the top part of the main sail. Thus keep the boat on her feet. When the heeling is under control, the vang should be harden to close the top of the main and get more power (speed).
When the boat heel too much (>25 degrees), it is actually slower because of side way slippage and less sail area expose to the wind.
If you have solid vang, then no need to mess with topping lift.
On a down wind, you'll harden the vang to help the main capture more air. It also help keep the main off the spreader. Hunter uses B&R rig, you can't swing the boom out more than 60 degrees.
If your sail is in good shape, it will make a lot of difference, but if your sail is past it's prime and all stretched out, it won't do very much (at that point, nothing will short of replacing the sail)
As already mentioned loose vs bolt rope doesn't matter in this case.
We just got a new loose-footed main and while I'm sure there is little or no difference in the way various sail controls work on it vs a bolt rope sail, I must say that it's amazingly illustrative to be able to easily see the effect of of changing one or more of these controls. Especially in the case of the outhaul. With a bolt rope sail it was difficult to see the effect of easing or trimming outhaul. With the loose footed sail any change is very east to see! Also, my sail maker (North Loft) says that loose footed is "the way to go"...
What a mate has to be careful with is the use of the outhaul on a loose footed mainsail. It is very easy (and common) to induce too much DRAFT DEPTH to a point where it becomes counter productive.
So the question becomes "how much is too much"? The rule of thumb is generally over 25% is too much.
So the question becomes "how much is too much"? The rule of thumb is generally over 25% is too much.
Thanks for all of the answers so far. It all seems to make sense. We are still getting used to sailing Daydream. The morning is promising 15 knot breeze with gusts to 23 knots so some reefing is on the cards but I will get a chance to play with the controls to see the differences in shape and performance.
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