Traveler and sail shape

From the Hunter Sailboat Owners Forum:

I know many crusing sailors are not aware that there are actually THREE separate sets of tackle pulling down along the foot of the mainsail. The traveller is only ONE of them, and the FACT is that for optimum sailing ability it must be located with regard to how the other two work. The first one that many people tend to overlook is the downhaul, pulling the sliding gooseneck down at the aft edge of the mast. Once you peak the halyard, take up on this like a ‘fine adjustment’. On boats over about 30 ft you had better be able to lead this to a winch– it has that much power and that much importance. The downhaul takes care of the tack of the main and front end of the boom for that all-important flat mainsail shape on the wind. The next one a lot of people forget to think about is the outhaul, drawing the mainsail clew aft on the boom. It is NOT, as many believe, a ‘set it and forget it’ thing although it’s easiest to draw it snugly before you peak the halyard and then let it out a little as you need to, as you will for a slab reef. On some racing boats this is led to a winch as well. The outhaul takes care of keeping the foot of the main straight (thus flat). The third one is the mainsheet, which pulls down on the aft end of the boom in complement with the downhaul at the forward end. These two work together– the only reason why you even have a traveller is to continue to pull STRAIGHT DOWN on this end, following the arc of the boom’s swing as you go off the wind. The downhaul doesn’t need one because it’s at the fulcrum of the boom’s arc and doesn’t swing round. Otherwise they are the same. Travellers located incorrectly will impose the wrong angle of pull and so require far too much effort on the tackle. If it is too far aft, the mainsheet begins to act as another outhaul, but not just pulling on a dacron sail to keep it straight– it is now pulling partly in tension on a T-6066 aluminium boom– as though any 4:1 purchase of 1/2″ line could effect that!! So there’s wasted work there, and poor sail shape as a result of the wrong angle of pull. A traveller too far forward (like ‘mid-boom sheeting’) will pull too much in the middle– too close to the downhaul which is already doing its half of the job, and again involve wasted effort with the lack of leverage from not pulling at the end of the boom where it’s easier. Again even a hefty aluminium boom has been known to break from inappropriate pull on the centre of it (in bad weather with mid-boom sheeting you have no other choice but to pull from there). I have said this before: do not underestimate the value of a flat mainsail. Modern sailors are going to full battens and Kevlar materials, NOT as gimmicks but sincere efforts to keep mainsail shape FLAT. At Cherubini we used to dread shakedowns with our late sailmaker John Eggers (who also did early Hunters) because he would crank everything in so tightly you swore half the cabintop would go to pieces. ‘Flat, flat, FLAT!’ he would insist– the main would be a like sheet of plywood (you could knock on it). In the 60s and 70s on the best race boats you would see a SECOND traveller for what you and I would call the preventer, arcing across the deck in a parallel arc to the sheet traveller (the fad of ‘mid-boom sheeting’ in the 70s was a cruisers’ pipe dream that they might combine the jobs of these two travellers into one– and some sailors actually believed it was better). Now they have huge hydraulic systems tied into the subframe or keel. Mainsail flatness really is that important to them. Sometimes I suspect that the ‘belly’ theories have only come round because of existing poor sail shape already– but if bellies were better than flatness, mainsails would probably never wear out. All the wear on old sails comes from keeping them under such tension. Relocating the traveller for ‘convenience’, such as to accommodate bimini tops, etc., must be viewed as a known compromise in sailing performance. Don’t be fooled into thinking the boat performs better with the traveller somewhere other than where it should be– know that the fact is it does NOT, and perhaps some have not realised it or maybe don’t care. That may be well and good for them. But there is only one correct place for the traveller and, before you decide to put it elsewhere, bear in mind you are moving a crucial piece of rigging and possibly for some unrelated reason. Would you move the mast to make the head bigger? –move the keel to get better headroom? –move the rudder post to accommodate an aft-cabin berth (or dinghy??). Neither should you consider moving something that essentially makes your boat go, saves on fuel, time, and stress on the hull, and ultimately shows you to be a knowledgeable sailor with a good-looking and well-performing boat.

J Cherubini II Cherubini Art