Self-Tackers: an Old Idea Revisited
The trend in boat design today is toward larger mainsails and easier-to-handle nonoverlapping headsails that, in many cases, take care of themselves.
In this sort of arrangement, there are several ways you can lead the sheet between the traveler, the sail, and a cleat or winch aft that will require the crew to make no adjustments as the boat comes about and falls off to the same sailing angle on the opposite tack. As with a jib boom, you can run a sheet between a traveler block and a clew block as many times as you want to produce the required mechanical advantage before running the sheet forward to a turning block at the tack, then aft. Today, though, a winch usually supplies most of the mechanical advantage, so sheets can be significantly shortened and routed more directly.
In an increasingly popular setup, the standing end of the sheet is secured to a padeye on one end of the traveler track. The lead then runs through a single block on the closest traveler car, up through a single sheave attached to the sail clew, then back through another single block on a separate traveler car and, finally, through a block on the opposite end of the track before running aft. This provides a 2-to-1 purchase, works very smoothly, and reduces deck clutter. The only drawback is that it requires a little longer track to allow space for two traveler cars for any given sheeting angle. Another basic option, which I first saw on Wally’s large boats, runs the sheet from the mast itself, usually well above the deck, down to one traveler block, up to the jib clew, down to the other traveler block, and back up the mast before turning back down to the deck via mast exits, much like an internal halyard. Similarly, one can run the sheet between blocks on the traveler and the clew before running the tail up to the mast.
Handling the Self-Tackers
Unlike a “normal” jib, which employs sheets that lead to cars that you can adjust fore and aft on tracks to maintain good sail shape no matter the height of the tack or strength or angle of the wind, the traveler position for self-tackers is fixed fore and aft. To set up and control the shape of a self-tacking jib, the sail requires a clew board with multiple positions to which to attach the sheet or sheet block.
Sailors will be wise to carry a temporary sheet or a handy billy (a tackle with one single and one double block) so they can take tension off the clew and change the position of the sheet on the clew board while under way. In actuality, though, once most cruisers get the sail adjusted properly for moderate airs, rarely will they change the clew block’s position.
The wider the boat, the longer the jib’s traveler track can be and the more a self-tacking jib will remain well shaped for work off the wind. Especially on a narrow boat that’s broad-reaching, the aft portion of the jib can still hook significantly back toward the rail, inducing drag rather than power. In that case, the crew on such a boat may want to use a reaching strut or some other type of pole to hold the clew outboard. On the other hand, when going upwind, the wider boats need to restrain the traveler cars from sliding too far outboard.
More important, there will be times a crew will want its jib not to self-tack. When the wind begins to roar, for example, you may want to heave to with a backed jib. Sailors can again employ a handy billy or rig a similar removable tackle to secure the jib in place. Some layouts, particularly for very wide travelers, include traveler control lines similar to those for a mainsail traveler. The crew can then fix the block positions or adjust the amount that the sheet blocks slide outboard.
Most boats can be retrofit with self-tacking arrangements, though this may require adding structural reinforcements for the track and any padeyes needed for blocks. But for those in the market for a more modern boat, chances are good that they’ll see an increasing number of self-tacking designs that offer a skipper greater ease and security for either a singlehanded outing on a sunny afternoon or a fully crewed offshore romp in a blow.
Steve Callahan, an occasional CW contributor, is a boat designer and author.