I have questions similar to the OP's. I'd like a traveler to reduce heel and weather helm on this SJ21, and to keep the mainsheet out of the cockpit on runs and deep reaches. The current setup is boom-end; thru dual blocks near the transom on either coaming; then down to a swiveling block with cam cleat on the aft cockpit floor.
If I understand correctly, the traveler performs at least two functions: it lets you vary the angle of the mainsheet, which affects tension on the leech (like a vang) and flatness of the sail; and it changes the point where the boom's upward force is transmitted to the hull.
So in heavy air, moving the traveler outboard means the sheet pulls vertically down hard on the boom, flattening the sail and reducing its power. In return, the boom pulls up hard on the leeward rail, which stands the boat up straighter, reducing heel and weather helm. This lift increases as the traveler moves farther outboard from the mast (centerline).
In light air, pulling the traveler to windward puts the mainsheet at a lower angle, allowing the boom to lift slightly, resulting in a fatter sail when close hauled. Same reason you vang off when pointing in light winds, right? It may also induce a bit of heel, which is desirable on many boats.
Does the above sound anything like correct?
I see alot of hybrid travelers, some of which up attach to the cockpit centerline. While that may place the sheet in your proper hand, won't it also partly reduce the effectiveness of a traveler? Here's one on a San Juan:
It uses 2:1 blocks on a line as the traveler, but then anchors the boom's midpoint to the centerline. Seems to somewhat defeat the purpose. Though it is a handy location.
Sooo.... Keeping in mind I'll have a tiller coming over the transom, what's the best traveler setup for my boat? I'm not keen on putting one mid-boom, across the cockpit. Want to keep a clean seating area. Across the back of the coamings? Right across the transom, blocked way up?
And where should the traveler controls cleat off, esp. for singlehanding in high winds? Does the above "double-ended mainsheet" prototype look feasible?
How far can a traveler beam span unsupported? And how far can it be behind the boom end? The X-shaped tracks claim to resist up to 20 degrees of lateral pull -- but aren't ALL travelers subjected to worse angles than that when running downwind?