Editing Sail components (section)

==Construction==
[[File:Kevlar-Carbon-Sail.JPG|thumb|Laminated sail with Kevlar and Carbon fibers.]]
[[File:Bladef16-1up.jpg|thumb|[[Catamaran]] with full-length ''battens'' in a ''laminated'' sail.]]
Sails are constructed of fabrics that may be woven or manufactured as films. The sail are often assembled of multiple panels that are arrayed in a manner that transfers the load from the wind to the sail's attachment points—a combination of corners and edges—that transmits the load into the mast and powers the boat. Construction of such sails requires stitching, bonding, reinforcements and other features to achieve this. Other sails are constructed directly from fibers, filaments and films.

===Materials===
{{See also|Sailcloth}}
The characteristics of a sail are due to design, construction and the attributes of the fibers, which are woven together to make the sail cloth. There are several key factors in evaluating a fiber for suitability in weaving a sail-cloth:<ref name=Textor/><ref name = Hancock>
{{cite book
 | last1 = Hancock
 | first1 = Brian
 | last2 = Knox-Johnson
 | first2 = Robin
 | title = Maximum Sail Power: The Complete Guide to Sails, Sail Technology, and Performance
 | publisher = Nomad Press
 | date = 2003
 | pages = [https://archive.org/details/maximumsailpower00hanc/page/288 288]
 | url = https://archive.org/details/maximumsailpower00hanc
 | url-access = registration
 | isbn = 9781619304277 }}</ref>
*''[[Elastic modulus|Initial modulus]]'' – The ability to resist stretching. Higher resistance is better for upwind sails.
*''[[Tensile strength|Breaking strength (tenacity)]]'' – Measured as a force per cross sectional area of fiber. Higher is better for sails.
*''[[Creep (deformation)|Creep]]'' – Describes the long term stretch of a fiber or fabric.  A material with creep may have a superior modulus, but lose its shape over time.
*''Resistance to [[Ultraviolet|ultraviolet light]]'' – Strength loss from exposure to the Sun’s UV rays measured by a standardized exposure test.
*''[[Fatigue (material)|Flex strength]]'' – Strength lost due to bending, folding, or flogging, which is frequently measured with an industry standard 50 fold test.
*''[[Cost-effectiveness analysis|Cost-effectiveness]]'' – Both the initial cost and its durability of the material define its cost-effectiveness over time.
Traditionally, sails were made from [[flax]] or [[cotton]] [[canvas]].<ref name = Hancock/> Materials used in sails, as of the 21st Century, include [[nylon]] for spinnakers—where light weight and elastic resistance to shock load are valued—and a range of fibers, used for triangular sails, that includes [[Dacron]], [[aramid]] fibers—including [[Kevlar]], and other [[liquid crystal polymer]] fibers—including [[Vectran]].<ref name = Hancock/><ref name=Textor/>

Woven materials, like Dacron,<ref>{{Cite web |title=Dacron sails {{!}} Elvstrøm Sails since 1954 |url=https://elvstromsails.com/sail-technology/sail-materials/woven-sail-material-dacron/ |access-date=2024-09-16 |website=elvstromsails.com |language=en-US}}</ref> may be specified as either high or low ''tenacity'', as indicated, in part by their [[Units of textile measurement#Denier|denier]] count (a unit of measure for the [[linear mass density]] of fibers). High-tenacity Dacron comes in multiples of 220, 350 and 570 deniers, whereas low-tenacity Dacron comes in multiples of 150, 250, and 400 deniers. Sailcloth is typically heat-shrunk to tighten the weave and then receives a chemical bonding finish of [[melamine]]. Such cloth is typically specified by deniers for [[Warp (weaving)|warp]] and fill ([[weft]]), e.g. 220/570.<ref name = Rice>
{{Citation
 | last = Rice
 | first = Carol
 | title = A first-time buyers checklist
 | newspaper = Cruising World
 | pages = 34–35
 | volume = 21
 | issn = 0098-3519
 | date = January 1995
 | url = https://books.google.com/books?id=cbA2Sw1wqGQC&pg=RA5-PA35
 | access-date = 2017-01-13 }}</ref>

===Panels and laminations===
[[File:Hals (Großsegel).jpg|thumb|Sail detail at the tack of a mainsail, showing various types of seam stitches where ''panels'' join, ''bolt ropes'' in the luff and foot, and two ''[[cringle]]s''.]]
Conventional sails comprise panels, which are most often stitched together, at other times adhered. There are two basic configurations, ''cross-cut'' and ''radial''. ''Cross-cut'' sails have the panels sewn parallel to one another, often parallel to the foot of the sail, and are the less expensive of the two sail constructions. Triangular cross-cut sail panels are designed to meet the mast and stay at an angle from either the warp or the weft (on the [[Grain (textile)#Bias|bias]]) to allow stretching along the luff, but minimize strutting on the luff and foot, where the fibers are aligned with the edges of the sail.<ref name = Colgate>
{{cite book
 | last = Colgate
 | first = Stephen
 | title = Fundamentals of Sailing, Cruising, and Racing
 | publisher = W. W. Norton & Company
 | date = 1996
 | pages = 384
 | url = https://books.google.com/books?id=MMP841X5Ke4C&pg=PA258
 | isbn = 9780393038118 }}</ref>

''Radial'' sails have panels that "radiate" from corners in order to efficiently transmit stress and are typically higher-performance than cross-cut sails. A ''bi-radial'' sail has panels radiating from two of three corners; a ''tri-radial'' sail has panels radiating from all three corners. Mainsails are more likely to be bi-radial, since there is very little stress at the tack, whereas head sails (spinnakers and jibs) are more likely to be tri-radial, because they are tensioned at their corners.<ref name = Hancock/>

Higher-performance sails may be laminated, constructed directly from multiple plies of [[Thread (yarn)|filament]]s, [[fiber]]s, [[taffeta]]s, and [[Plastic film|films]]—instead of woven textiles—and adhered together.  ''Molded sails'' are laminated sails formed over a curved mold and adhered together into a shape that does not lie flat.<ref name = Hancock/>

Where a sail may rub against a spreader on the mast, a [[spreader patch]] may be placed on a jib, when it overlaps with the mast,<ref>{{Cite book |url=https://books.google.com/books?id=7TVvAAAAQBAJ&pg=PA111 |title=The Annapolis Book of Seamanship: Fourth Edition |last=Rousmaniere |first=John |date=2014-01-07 |publisher=Simon and Schuster |isbn=9781451650242 |language=en}}</ref> or on the mainsail, where it may interfere when [[Furl (sailing)|furled]]<ref>{{Cite book |url=https://books.google.com/books?id=cbA2Sw1wqGQC&pg=RA7-PA25 |title=There's the rub |last=Neal |first=Tom |date=January 1995 |work=Cruising World |location=Newport, Rhode Island |pages=25 |language=en}}</ref> or when the sail is backwinded against the [[Mast (sailing)|mast]].<ref>{{Cite book |url=https://books.google.com/books?id=2JIbS0c1XPwC&pg=PA185 |title=The New Book of Sail Trim |last=Textor |first=Ken |date=1995 |publisher=Sheridan House, Inc. |isbn=9780924486814 |pages=185 |language=en}}</ref>
<gallery>
 Zagiel horyzont.svg|Cross-cut panels
 Zagiel birad.svg|Bi-radial panels
 Zagiel gwiazda.svg|Tri-radial panels
</gallery>

===Stitching and bonding===
Conventional sail panels are sewn together. Sails are tensile structures, so the role of a seam is to transmit a tensile load from panel to panel. For a sewn, textile sail this is done through thread and is limited by the strength of the thread and the strength of the hole in the textile through which it passes. Sail seams are often overlapped between panels and sewn with zig-zag stitches that create many connections per unit of seam length.<ref name = Hancock/> Measures for seam structural attributes—shown with a typical value for a sewn seam—include:<ref name = JonesStylios>
{{Citation
 | last1 = Jones
 | first1 = I.
 | last2 = Stylios
 | first2 = G.K.
 | title = Joining Textiles: Principles and Applications
 | publisher = Elsevier
 | series = Woodhead Publishing Series in Textiles
 | year = 2013
 | pages = 624
 | url = https://books.google.com/books?id=mw9IAgAAQBAJ&pg=PA457
 | access-date = 2017-01-12
 | isbn = 9780857093967 }}</ref>
*''Breaking force'' ([[newtons]]) – {{convert|630|N|lbf}}
*''Elongation'' (percent) – 22%
*''Strength'' (newtons/millimetre) – {{convert|14|N/mm|lbf/mm}}
*''Modulus of elasticity'' (newtons/millimetre) – {{convert|1.2|N/mm|lbf/mm}}
Whereas textiles are typically sewn together, other sail materials may be [[Ultrasonic welding|ultrasonically welded]]—a technique whereby high-frequency [[Ultrasound|ultrasonic]] [[Acoustics|acoustic]] [[vibration]]s are locally applied to workpieces being held together under pressure to create a solid-state [[Welding|weld]].  It is commonly used for [[plastics]], and especially for joining dissimilar [[Materials science|materials]].<ref name = JonesStylios/>

===Edge construction===
[[File:Liekleine.jpg|thumb|Leech line with jam cleat to control the tension on the leach of a foresail.]]
{{See also|Bolt rope|Roller furling}}
Sails have a variety of treatments at their edges, either to attach the sail to a stay, spar or mast or to prevent a free edge from fluttering or fraying.
*''[[Bolt rope]]s'' are sewn onto the edges of the sail to reinforce them, or to fix the sail into a groove in the boom, in the mast, or in the luff foil of a [[Roller furling|roller-furling]] jib.<ref name="Kipping1847">{{cite book |first=Robert |last=Kipping |title=The Elements of Sailmaking: Being a Complete Treatise on Cutting-out Sails, According to the Most Approved Methods in the Merchant Service... |url=https://books.google.com/books?id=3n8EAAAAQAAJ |year=1847 |publisher=F.W. Norie & Wilson |pages=58–72}}</ref>
*''Leech lines'' are found on mainsails and large jibs to tighten the leech and prevent fluttering. They run through a sleeve on the leech from the head to the clew, where there is usually a clam cleat to tighten it. Occasionally, ''foot lines'' perform an analogous function on a loose-footed sail.<ref name = Nicolson>
{{cite book
 | last = Nicolson
 | first = Ian
 | title = A Sail for All Seasons: Cruising and Racing Sail Tips
 | publisher = Sheridan House, Inc.
 | date = 1998
 | pages = 124
 | url = https://books.google.com/books?id=nO3M-8JAhH4C&pg=PA93
 | isbn = 9781574090475 }}</ref>
*''UV protection panels'' are usually affixed to the leech and foot of roller furling jibs to prevent ultraviolet rays from reaching the sailcloth while the sail is not in use. These are typically a dark color to absorb the harmful rays.<ref name = Pinney>
{{cite book
 | last = Pinney
 | first = Tor
 | title = Ready for Sea!: How to Outfit the Modern Cruising Sailboat and Prepare Your Vessel and Yourself for Extended Passage-making and Living Aboard
 | publisher = Sheridan House, Inc.
 | date = 2002
 | pages = 256
 | url = https://books.google.com/books?id=KbIDXWJZ610C&pg=PA45
 | isbn = 9781574091441 }}</ref>

===Reinforcements at attachment points===
[[File:Kopfbrett1.jpg|thumb|''Headboard'' on a mainsail.]]
The corners of triangular sails are typically areas of high stress and consequently often have reinforced layers and tape radiating from, whether cross-cut or radial in construction. Their corners are always attached to a [[shackle]], attached to a line or spar—the [[halyard]] at the head, a shackle at the tack, and the [[outhaul]] at the clew. The connecting shackle runs through a [[grommet]] at each of these points. There are additional points where reinforcing and grommets may occur: at the [[Cunningham (sailing)|cunningham]], a [[downhaul]] used to flatten a mainsail (jibs may have a similar feature), and along the foot of a [[Genoa jib]] to allow a line to lift it out of the waves. The head of a triangular sail may have a rigid ''headboard'' riveted to it in order to transfer load from the sail to the halyard.<ref name = Colgate/>

Square sails and gaff-rigged sails also have grommets at corners. Only the clews on a square sail take a comparatively large amount of stress, because the head is supported along the spar. Three sides of gaff-rigged sails are attached to a mast or spar.{{sfn|King|Hattendorf|Estes|2000|page=146}}

===Battens===
[[File:Verschiedene Segellatten.jpg|thumb|Sail battens made from a variety of materials.]]
{{Main|Sail batten}}
{{See also|Junk rig}}

A ''sail batten'' is a flexible insert in a fore-and-aft sail that provides added stiffness and definition to the sail's airfoil cross-section.<ref name=Textor/> The most common use of sail battens is in the [[Roach (sail)|roach]] of a mainsail. The batten extends the leech past the line that runs from the head and the clew of the sail to create a wider sail towards the top. Cruising sailboats may have four to six battens. Racing sailboats may have full-length battens, as well, that allow for better sail shape.<ref name=Textor/> Battens are also found in jibs of [[Beachcat|beach-cat]] catamarans.<ref name = Berman>
{{cite book
 | last = Berman
 | first = Phil
 | title = Catamaran Sailing: From Start to Finish
 | publisher = W. W. Norton & Company
 | date = 1999
 | pages = [https://archive.org/details/catamaransailing00phil/page/219 219]
 | url = https://archive.org/details/catamaransailing00phil
 | url-access = registration
 | isbn = 9780393318807 }}</ref> Most battens are fiberglass [[pultrusion]]s with a thin, rectangular cross section.<ref name=Textor/>

[[Junk rig]]s feature full-length battens that facilitate short-handed sail handling, including reefing. The battens are attached loosely to the mast with lines called ''batten parrels'' that allow fore-and-aft motion as the sail is controlled by individual sheets leading to multiple battens.<ref name = Mudie>
{{Citation
 | last1 = Mudie
 | first1 = Rosemary
 | last2 = Mudie
 | first2 = Colin
 | title = The history of the sailing ship
 | publisher = Arco Publishing Co.
 | year = 1975
 | pages = 152
 | isbn = 9780668037808
 | url = https://books.google.com/books?id=SyFUAAAAMAAJ
 }}</ref>