Neil Pryde Terminology

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n this discussion we use many technical terms with very specific meanings, While most arestandard terms, other sailmakers sometime use alternative terms. Glossary of TermsHalyards and cunninghams
Halyards are lines used to pull the sails up and to adjust the position of the draft (sail camber, curvatureor “fullness”) fore or aft in the sail. They don’t significantly alter whether the sail is more full or less full.More tension on the halyards brings the draft of the sail forward; less tension drops it back. (figure 1)Cunninghams are down haul lines for fine tuning luff tension after the halyard is tightened and cleatedoff. It has the same effect on the draft as the halyard. Figure 1 Mainsail outhaul
Halyard tension movesdraft forward and aft,with little effect on howfull the sail is. Line used to flatten or make fuller the bottom third of the sail. Tightening the outhaul flattens this part of the sail and makes the aft section (exit or leech) straighter. Loosening the outhaul makes the sail fuller in the bottom so the leech becomes a rounder, fuller exit, providing more power. (figure 2) Main sheet Figure 2
Line giving control over the movement of the boom. Upwind, it is used to control sail twist (tightermainsheet reduces twist, looser mainsheet increases it). Downwind it is used to control the lateral position of the boom in and out. (figure 3) Outhaul tension effectshow full the draft is, withlittle effect on it’sposition forward or aft. Boom vang
A line at 45 degrees from bottom of mast to underside of boom. This adjustment is predominantly used when sailing off the wind to control sail twist. Tightening boom vang reduces twist, loosening increases twist. Figure 3 Genoa fairlead
Block through which genoa sheet passes. This has two functions which are interactive: moving the fairlead aft will tend to increase twist and, at the same time, flatten the bottom third of the sail. Movingthe fairlead forward reduces twist and makes the bottom of the sail fuller. (figure 4) Genoa sheet
Increase sheet tension always reduces twist, but—and this depends on the position of the fairlead —genoa sheet tension also has an effect on the fullness of the sail. If the fairlead is a long way forward thesail will tend to get fuller as the sheet is tightened. If the fairlead is a long way back, the sail will getflatter, especially in the bottom third. Backstay
The backstay is the single most effective adjustment on any boat (except those with extremely stiffmasts). Increasingly backstay tension flattens both the mainsail and jib simultaneously, as follows: Itpulls the mast top backward, which flexes the middle of the mast forward, thus flattening the mainsail. This also makes the forestay tighter, which pulls the jib body forward, flattening it as well, especially inthe entry. (figure 5a and 5b) As the mainsheet istightened, the boom islowered, and the the twistis pulled out. Woven materials
Any material that is made up of individual yarns woven together to form a fabric. It can be finished todifferent levels of stiffness through the addition of a coating of hardener. (Tetoron, Dacron, polyester,Nylon, and other company trade names)