#gennaker

GLOSSARY OF TERMS

 ASPECT RATIO: The luff length of the sail divided by the foot length

 BIAS: The direction diagonally across a piece of fabric at 45 degrees to the warp and fill.

 COUNT: The number of fibres per inch in the warp or fill.

 CREEP: Permanent, continuous elongation of a fibre under a sustained load.

 CRIMP: The ‘waviness’ of the fibre or yarn when it is laid over and under fibres or yarns in a fabric. Crimp can contribute to the elongation of a fabric under load as it is pulled out of the loaded direction and pushed into the less heavily loaded direction.

 CROSS CUT: A sail panel layout in which the seams run roughly parallel to one another, typically perpendicular to the leech.

 DACRON (Polyester): A manufactured fiber introduced in the early 1950s, polyester has been the most common fiber used in sailcloth. It is most commonly referred to by its DuPont trade name Dacron®, the name given to the Type 52 high modulus fiber made specifically for sailcloth. Recent advancements by Allied Signal have produced a fiber called 1W70 polyester that has a 27% higher tenacity than Type 52. Other polyester trade names include Terylene®, Tetoron®, Trevira® and Diolen®. Polyester’s desirable properties include excellent resiliency, high abrasion resistance, high UV resistance, high flex strength and low cost. Low absorbency allows the fiber to dry quickly. Although polyester has been replaced by higher modulus fibers such as those used in the Doyle Stratis products, its proven durability and price point has seen it remain a popular cruising sailcloth fiber. Dacron sails are most popular sails.

 DENIER: A measure of the weight of a continuous fibre filament. It is the weight in grams of 9,000 metres of a given fibre. The lower the number the finer the fibre. Higher denier, heavier fabrics are generally more rugged and durable.

 DENIER PER INCH: Often referred to as DPI and is a measure of the fabrics relative weight and strength, expressed as the numbers of fibres over inch generally in the primary yarn direction.

 DYNEEMA: Equivalent to Spectra®, Dyneema® is produced by the Dutch company DSM. It is often used by European sailcloth manufacturers, is available in a wider variety of yarn sizes than Spectra, and is growing in popularity in North America.

 ELONGATION: The difference between the initial length of fabric sample and its length after stretching, expressed in 1/100ths of an inch.

 FIBRE: The basic entity that is twisted into yarns and then used in the production of a fabric.

 FILAMENT: A single fibril of natural or synthetic textile fibre. Filaments are twisted or bunched to form fibres.

 FILL (WEFT): The yarns or fibres that run across the width of the roll of fabric, perpendicular to the warp direction.

 FILM: An extruded sheet of plastic. Films desirable properties include low stretch, good bias stability, low porosity and good adhesion. Less desirable properties include low tear strength and relatively high physical shrinkage due to creases and folds in the film.

 FLEX STRENGTH: The ability of a fibre to retain its strength after being folded back and forth – commonly expressed as a percent loss in breaking strength after flutter or fold testing.

 GSM: Weight expressed in grams per square meter

 HAND: A subjective term for the way the fabric feels when touched. Terms like softness, crispness and dryness all describe the hand of the fabric.

 INITIAL MODULUS: A measure of a material's ability to resist stretch. Initial modulus is usually expressed as grams of load per unit stretch for a certain fibre denier. The higher the initial modulus, the less the fibre will stretch.

 INSERT: A yarn or fibre laid directly into a fabric without first being woven or put into a scrim.

 LAMINATE: Fabric constructed from layers of film, scrim and/or taffeta flued together under high pressure and/or heat to form a composite sail material.

 NYLON: First produced in 1938, nylon is the first completely synthetic fiber developed. In the sailcloth industry, it is used in full radial and asymmetrical spinnakers because of its light weight, high strength, superior abrasion resistance and flexibility. It does not, however, have good resistance to stretch, which is not a big factor in downwind sails, but makes it unsuitable for mains and headsails. Nylon is more susceptible to UV and chemical degradation than polyester and should never be washed with chlorine bleach. Also, its physical properties can change by as much as 100% due to moisture absorption.

 PRIMARY YARN DIRECTION: The direction that is most resistant to stretch, typically due to higher yarn count or a higher modulus fibre.

 RADIAL: A panel layout where the seams and panels radiate from the corners of the sail in the direction of the highest load.

 SAILMAKERS WEIGHT: Weight in ounces of a piece of fabric measuring 2.5 inches x 36 inches

 SCRIM: A base fabric component created by laying out fibres in a grid pattern with the fibres joined at their intersection. A scrim can be constructed by passing fill and warp yarns over and under one another; by knitting, in which the fibres and tied at each intersection, or by laying the fibres straight across one another and connecting them at the intersections with glue.

 TECHNORA: Produced in Japan by Teijin, Technora exhibits a similar or somewhat lower initial modulus than Kevlar 29 and slightly higher resistance to flex fatigue. The fiber’s lower UV resistance is enhanced by dying the naturally gold fiber black. Technora is most often used as bias support (X-ply) in laminate sailcloth.

 TAFFETA: An unfinished fabric employed as a covering, usually in a laminate sailcloth, often enhancing durability and chafe resistant.

 TENACITY: The tensile stress at rupture of a fibre expressed in grams or force per denier. Tenacity relates to the breaking strength of fibres and should not be confused with modulus, which relates more directly with a fibres ability to resist stretch.

 TENSILE STRENGTH: A measure of the ability of a fibre, yarn or fabric to withstand pulling stresses.

 THREADLINE: The direction of the fibres or yarns in the warp, fill or bias.

 UV RESISTANCE: A measure of the effect of sunlight on cloth. UV resistance is usually expressed as the time it would take for a material exposed to sunlight to lose half of its breaking strength.

 WARP: The yarns or fibres in a fabric that run the length of a roll or cloth and in a woven fabric are interlaced with the fill (weft) yarns.

 WOVEN: Material made by interlacing fibres over and under each other in a regular pattern. Types of weaves include: plain, leno and basket among others.

SPINNAKER e GENNAKER sono vele progettate apposta per le andature portanti e, sfruttando il vento al meglio, permettono di navigare con vento in poppa. Ne esistono innumerevoli varianti, con forme, colori, materiali e grammature studiate per una funzione specifica o precise intensità di vento.

Lo spinnaker è controllato da tre punti: il punto di drizza, con cui la vela viene issata e ammainata e i punti di mura e scotta che si alternano durante l’uso. Per mantenere la vela ben fuori dalla prua della barca occorre fissare sempre il punto di mura al tangone.

Il gennaker (il cui nome deriva dalla fusione di genoa e spinnaker) è sempre una vela di prua molto leggera, studiata per le andature portanti e spesso molto colorata. Presenta però delle notevoli differenze rispetto allo spinnaker: è asimmetrica,è generalmente più piccolo,il punto di mura è fissato ad un appendice di prua chiamata bompresso,non necessità di tangone.

Per queste sue caratteristiche il gennaker è molto più semplice da manovrare e mantiene la navigazione stabile e sicura.

Lo spinnaker e il gennaker non svolgono le stesse funzioni. Le forme, ben differenti, rendono il primo molto efficiente tra il granlasco e la poppa piena mentre il secondo lavora al meglio con andature tra il traverso e il lasco.

(Estratto da ormeggionline.it)

Sails Explained The different sails of a sailboat

While we tend to see only two most of the time, there are different sails that can be used on our sailing boats. Sailors change them for better performance, depending on the sea conditions. It is good to know the name of these sails and how each sail is used. The sails need to be adapted to the point of sail, depending on how close they are to the wind.

 The flat sails

 The Mainsail

This sail is attached to the boom and the back of the mast. The mainsail offers the essential property of being reduced depending on the strength of the wind, which involves taking in a reef or shaking one out, by lowering the sail on the mast. This sails is not always the biggest sail on board, as the spinnaker and big gennaker have a larger surface. The mainsail has different surface areas: full mainsail, 1 reef, 2 reefs or 3 reefs for some of them. Some racers even have a fourth reef !

  J1 or Solent

The J1 is attached to the biggest stay, which goes from the bow to the mast head. It’s a flat sail that suited to sailing close to the wind, when the wind is between 10 and 15 knots. As the J1 is a big sail, it can also go up to 120 or even 130 degrees to the wind.

The J3 or Staysail

The J3 is on the shortest stay of the boat. It is the smallest jib onboard  to be used in heavy weather. On the bigger boat, it can be used in combination with another headsail, from 90 degrees to 160 degrees to the wind, as well as being used downwind. It stabilises the boat and helps direct the flow of air towards the mainsail.

 J2 J3

J is quite used to refer to the jib sails. The numbers correspond to the attachment points on the stays, which are positioned closer or further away from the stern of the sailing boat. Number 1 is on the bow of the boat. Number 2 is slightly further back on the deck and number 3 quite some way back close to the mast, when smaller sails are required. The J2 is the sail that is attached to the main cable and is fitted to a furler. This is a rather flat sail with a wide range of uses from 45 to 110/120 degrees to the wind.

Downwind sails

 The Spinnaker

The spinnaker is the big balloon sail for use with the downwind. This huge sail is the biggest on board. The spinnaker is attached to the bowsprit. It can be an asymmetrical or symmetrical sail, with or without pole. It can be used with the wind from astern from 5 to 25 knots. When sailing alone, it must be bring down sooner.

The Gennaker

Attached to a furler, this big downwind sail is used in similar conditions to the spinnaker. Sailors use it between 15 and 30 knots, at between 120 and 160 degrees to the wind.

 Code Zero

Code zero is more flat sail. It is used when sailing close to the wind in lighter airs.

 The Storm Sail

Storm sail is very small and strong sail for use in storms.