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main sheet traveler further to windward
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Author:  fpichel [ Sun Jul 24, 2011 12:54 pm ]
Post subject:  main sheet traveler further to windward

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I was wondering today if I could increase my upwind sailing angle if I could cleat the traveler car for the main sheet further to windward than the center of the boat.
The current set up does not allow this. Has this been tried before? Is there some reason this wouldn't work?
If you can see my illustration the angle of the boom is the same on each boat, but the one with the car further to windward seems like it could beat upwind better.

Thoughts?

thanks
frank

Author:  OlderBowman [ Sun Jul 24, 2011 3:18 pm ]
Post subject:  Re: main sheet traveler further to windward

you can in some cases increase windward pointing by raising the boom above centerline, but the amount is small, maybe up to 2 inches, speed will suffer becasue of the high pointing. beyond that the relationship between the main and jib becomes way unbalanced, the slot becomes less effective trying to pull in the jib far enough to match the angle of attack of the main. cross sheeting the jib can help.

a more effective way to point high is to develop 'speed wrinkles', where the downhaul is eased off, sheeting is way in. you get diagonal wrinkles running down and back from the mast in the lower third of the main, whereas the upper half of the sail is trim very tight.

Author:  srm [ Mon Jul 25, 2011 4:25 am ]
Post subject:  Re: main sheet traveler further to windward

I don't think you're going to see any upwind improvement by moving the traveler to windward. Yea the bows might point closer to the wind, but you'll be going slower and have a higher leeway angle. Overall upwind performance is likely to suffer. These boats go better upwind (better VMG) when you take advantage of the increased speed from footing off rather than trying to pinch real high like a monohull.

sm

Author:  MBounds [ Mon Jul 25, 2011 9:00 pm ]
Post subject:  Re: main sheet traveler further to windward

fpichel wrote:
Has this been tried before?
Actually, it has.

When Hobies were first introduced, the traveler system had that capability. However, the complexity involved proved to be unworkable (two traveler lines, two cleats and a traveler that wouldn't move under load). The "self tacking" system that's on the boats now (and used on nearly every beach cat today), has proven to be idiot proof and significantly faster.

fpichel wrote:
Is there some reason this wouldn't work?
Depends on your definition of "work". Sure it will "work", but is it faster? No. Is it easy to use? No.

Sailboats going upwind are a balancing act - the sail's sideforce is countered by the lift generated by the hull (and boards - if the boat is so equipped). In order to generate lift, there has to be some sideslip. It's a very complex situation and just pulling the sail higher to weather has all sorts of unintended consequences - like increased sideslip.

The bottom line is that Hobies (and catamarans in general) do not respond well to weather sheeting the traveler.

Author:  Karl Brogger [ Fri Jul 29, 2011 6:44 am ]
Post subject:  Re: main sheet traveler further to windward

Can you so a split tail traveler on the H16? Virtually every modern design is setup this way, makes getting the traveler actually centered easier.

Author:  MBounds [ Sat Jul 30, 2011 7:51 am ]
Post subject:  Re: main sheet traveler further to windward

Karl Brogger wrote:
Can you so a split tail traveler on the H16? Virtually every modern design is setup this way, makes getting the traveler actually centered easier.
Class rules prevent tapering lines, and I think a split-tail traveler line qualifies as that.

However, there's no reason for it on a Hobie 16. The traveler is almost never fully centered anyway. Most of the time, we're traveled out 4" or so upwind. Helps keep the upper part of the sail from stalling, especially in lighter air.

Author:  fpichel [ Sun Aug 14, 2011 1:59 pm ]
Post subject:  Re: main sheet traveler further to windward

MBounds wrote:
However, there's no reason for it on a Hobie 16. The traveler is almost never fully centered anyway. Most of the time, we're traveled out 4" or so upwind. Helps keep the upper part of the sail from stalling, especially in lighter air.


Thanks. That's good to know. I'm still learning about the aerodynamics of a sail, and its relationship to the boat.
To be clear, you're saying the traveler should almost always be at least 4" to the leeward side of center? I've been doing it wrong! When beating to windward I've been centering the traveler, trying to get the telltales to stream back.

thanks

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