How much travel does a Traveler need?

Probably me, but I dont quite understand that bit. Presumably the two mainsheet tackles that both pull on the boom are called vangs? If that is the case, then I would have thought that pulling on either or both of them would reduce twist in the mainsail. And pulling on the leeward one only would both reduce twist and free off the boom whereas pulling on the windward one would both reduce twist and move the boom to windward. If you need to reduce heeling moment one might think that it would be good to both free off the boom and allow twist to increase, so as to lower the center of effort, this would suggest playing the windward vang only to cope with gusts - is that right?

 

I was calling them "vangs" because they do the job of twist control. But they aren't really vangs because they aren't led to the mast step.

There's no point in pulling on the windward one. The mainsheet pulls to windward and has more of a downward component. It's really the mainsheet that is providing the leech tension to control the twist. The vang/preventer is taking out the horizontal component of the mainsheet tension that would otherwise move the boom to windward.

You can get the same effect from a double-mainsheet arrangement that uses two main sheets led to opposite sides of the aft beam. By coordinated use of the mainsheets, you can put the boom wherever you want. I think the system Chris White designed for my boat is easier to use because you still mainly use the single mainsheet for trimming the sail. The vang/preventer is a secondary control.

When I first had the boat, I rigged up the system differently. Instead of having the ends of the vang/preventer attached to the boom, rigged it as a bridle, running through a block on the boom with the ends in the cockpit. The bridle effectively became an elliptical traveler with the foci of the ellipse at the blocks at the ends of the beam. This worked fairly well, but when the bridle was tightened down, it would limit how far the boom went out when the sheet was eased. And the loads on the bridle were high. An accidental jibe as a squall approached ripped one of the blocks right off the beam. So after the block mountings were reinforced, I rigged it back the way Chris White had designed it. Pulling on the leeward one is easier than increasing the tension in the bridle.

 

I think you can legitimately call them that- so similar to a gaff vang that goes nowhere near the mast step.

J.

 

Thanks for posting your setup Tom. I was going to rig a double mainsheet but will try this first.

 

Question for Tom. From what I'm reading about your system a tackle isn't needed for the outboard vang/preventer just a single block because the mainsheet can add the muscle once the location is set?

 

@ Tom so thats like a double preventer kinda?


Barry

 

My boat has some small secondary winches on the cockpit coaming and clutches on the beams. If needed, I can winch in the vang and then the clutch will hold it. But more often than not, all I need to do is ease the mainsheet, give a good pull on the vang by hand, and then sheet in the main hard. Hand tension is enough to remove a lot of twist from the main.

The same secondary winches are used to hold the running backstays. Of course, when using the runners, it's the windward winch that's occupied and the leeward winch is still available for the vang. On my to-do list is adding clutches for the runners so the winches can be completely free when jibing.

 

Yes. On the plans, Chris White's callout says vang/preventer.

 

very cool! i love the idea of it? I suppose if there was a windlass in the middle somehow, you could actuate them both as if it was a track setup with benefits. And if there was a stressed vang link in that too (Like a idler pulley) you could unclasp both for setting angle in sail. And you still get all the out back room of no track.

Barry

 

I'm going to try it though I'll skip the clutches and try cleats, I figure I can un- cleat and use the horn as a brake when easing if I need to. I use my secondaries for the barber haulers, you never know I might evolve towards the clutch route.

 

I'm also going to put in a more forward location for the vang/preventer when running dead downwind. Our running backs use tackle and at that point I need to release the lee one and move around anyway. Most of the time if down wind tacking the main doesn't need to go out that far.