A while back on another forum someone was wondering if it made a difference if you use the main halyard versus the downhaul to adjust the mainsail. I think the general consensus of the board was that it did not matter. I have often thought about this since that time and I have come up with some questions. (Caution: I am an analyst and yes I have heard all the jokes.) If we increase tension on the downhaul we change the angle of the luff/foot point. If we increase tension on the halyard we change the angle of the luff/leech point. Therefore, it seems that it would make a difference in sail shape depending on which adjustment was used. Would you agree or disagree and would you please share your wisdom? Thanks, Yeto
Halyard vs downhaul to adjust mainsail question
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hmmmm.....
I mostly use the downhaul after pulling the halyard all the way, but I've only sailed small boats. I'm 6'0, and that assures the boom is as high as it can be. Of course that increases the leverage of the sails, increaseing the need to hike out further, but also, the sails are higer and in better air. That's my thinking anyway. The bottom line is I don't think it matters much, as long as your sail shape is good. I may be missing something whaen you say "we change the angle", as I only see it as "we change the location" of the foot or leech. Take Care, Steve
I mostly use the downhaul after pulling the halyard all the way, but I've only sailed small boats. I'm 6'0, and that assures the boom is as high as it can be. Of course that increases the leverage of the sails, increaseing the need to hike out further, but also, the sails are higer and in better air. That's my thinking anyway. The bottom line is I don't think it matters much, as long as your sail shape is good. I may be missing something whaen you say "we change the angle", as I only see it as "we change the location" of the foot or leech. Take Care, Steve
Yeto--mainsail controls
Hi Yeto, You are right, the two controls do act differently--downhaul tightens luff selectively and removes fwd shelf at the boom; halyard reduces shelf and moves belly aft. I think that you can tweak each of these with the cunningham (tighten luff and enhance shelf) and clew outhaul (moves belly aft selectively down near the boom.) Cheers, Rod
Hi Yeto, You are right, the two controls do act differently--downhaul tightens luff selectively and removes fwd shelf at the boom; halyard reduces shelf and moves belly aft. I think that you can tweak each of these with the cunningham (tighten luff and enhance shelf) and clew outhaul (moves belly aft selectively down near the boom.) Cheers, Rod
Rod's got it right
Pulling on a corner (tack, head or clew), affects the opposite 'side' of a sail Also the luff attachment system (slugs, boltrope, or 'sliders') usually involves a lot of additive friction so the force of either downhaul, halyard is lessened the further away you go from the point of force application .... 'nutherwords': putting tension in the halyard 'more' affects whats happening at the 'top' of the sail; pulling on the downhaul or cunningham affects more whats happening at the 'bottom' of the sail .... all due to 'frictional' differences with the sail slugs, etc. When you tension a sail control, it takes some time for all the frictional forces to 'equilibrate'.
Pulling on a corner (tack, head or clew), affects the opposite 'side' of a sail Also the luff attachment system (slugs, boltrope, or 'sliders') usually involves a lot of additive friction so the force of either downhaul, halyard is lessened the further away you go from the point of force application .... 'nutherwords': putting tension in the halyard 'more' affects whats happening at the 'top' of the sail; pulling on the downhaul or cunningham affects more whats happening at the 'bottom' of the sail .... all due to 'frictional' differences with the sail slugs, etc. When you tension a sail control, it takes some time for all the frictional forces to 'equilibrate'.
Downhaul
My downhaul pulls the gooseneck down. The only effect I see is that the entire sail is moved up or down, with tension applied or released along the luff. There may be changes in sail shape if the downhaul is the ONLY control adjusted. I don't get too technical when I'm out, so I don't adjust the luff tension after the sail is hoisted. Downhaul is not conveniently located. I have enough fun playing with the traveller, mainsheet, vang, leech and outhaul.
My downhaul pulls the gooseneck down. The only effect I see is that the entire sail is moved up or down, with tension applied or released along the luff. There may be changes in sail shape if the downhaul is the ONLY control adjusted. I don't get too technical when I'm out, so I don't adjust the luff tension after the sail is hoisted. Downhaul is not conveniently located. I have enough fun playing with the traveller, mainsheet, vang, leech and outhaul.
Sail High
Seems to me that tightening the main halyard would raise the top of the sail a bit, up where wind speed is usually highest, that is in addition to shape changes others have mentioned. RK
Seems to me that tightening the main halyard would raise the top of the sail a bit, up where wind speed is usually highest, that is in addition to shape changes others have mentioned. RK
downhaul and cunningham
Ed's comment is good because we often confuse downhaul with cunningham. The downhaul is connected to the boom at the goosenect, which slides in the sail track. The cunningham is connected to the sail's luff a few inches above the tack with the gooseneck nomally fixed to the mast. I think the cunningham is much more effective as a luff control, that's why I converted when I bought a new main a few years ago.
Ed's comment is good because we often confuse downhaul with cunningham. The downhaul is connected to the boom at the goosenect, which slides in the sail track. The cunningham is connected to the sail's luff a few inches above the tack with the gooseneck nomally fixed to the mast. I think the cunningham is much more effective as a luff control, that's why I converted when I bought a new main a few years ago.
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