sail

　 　 　 　 　

WordNet

1. traverse or travel on (a body of water); "We sailed the Atlantic"; "He sailed the Pacific all alone"
2. a large piece of fabric (usually canvas fabric) by means of which wind is used to propel a sailing vessel (同)canvas, canvass, sheet
3. any structure that resembles a sail
4. travel on water propelled by wind; "I love sailing, especially on the open sea"; "the ship sails on"
5. a palace built in the 17th century for Louis XIV southwest of Paris near the city of Versailles (同)Palace of Versailles
6. a city in north central France near Paris; site of the Palace of Versailles that was built by Louis XIV in the 17th century
7. a sail (or either of a pair of sails) immediately above the lowermost sail of a mast and supported by a topmast
8. a boys ensemble; copied from a sailors uniform
9. gliding in a parasail (同)paragliding
10. riding in a sailboat
11. the departure of a vessel from a port

PrepTutorEJDIC

1. 〈C〉〈U〉『帆』;《集合的に》一隻の帆全部 / 〈C〉帆のような物;風車の羽根,カエデの種子の羽根など / 〈C〉《単複同形で》帆船;船 / 〈C〉《単数形で》(短い)船旅,船遊び;〈U〉《時にa sail》航程 / 《副詞[句]を伴って》〈船が〉『航海する』 / (…から…へ)『出航する』《+『from』+『名』+『for』(『to』)+『名』》 / 《副詞[句]を伴って》〈人が〉『船で旅をする』,航海する / ヨットを操る,帆走する / 《副詞[句]を伴って》すべるように進む(飛ぶ);〈人が〉さっそうと歩く / 〈人・船などが〉〈海・川など〉‘を'渡る / 〈船〉‘を'操る,走らせる
2. ベルサイユ(フランス北部の都市,ルイ14世の宮殿がある)
3. (船の)中檣帆,トップスル
4. 〈U〉帆走,ヨット遊び / 〈C〉航海 / 〈C〉〈U〉出航,出帆 / 〈U〉航海術

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2019/06/28 18:20:05」(JST)

wiki en

[Wiki en表示]

Sail rigs

Square rigged frigate.

Lateen-rigged dhow.

Lug-rigged vessel (lugger).

Bermuda-rigged yawl.

Sailing hydrofoil catamaran with wingsail.

For other uses, see Sail (disambiguation).

See also: Sail components, Sailing, Sailboat, and Sailing ship

A sail is a tensile structure—made from fabric or other membrane materials—that uses wind power to propel sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles. Sails may be made from a combination of woven materials—including canvas or polyester cloth, laminated membranes or bonded filaments—usually in a three- or four-sided shape.

A sail provides propulsive force via a combination of lift and drag, depending on its angle of attack—its angle with respect to the apparent wind. Apparent wind is the air velocity experienced on the moving craft and is the combined effect of the true wind velocity with the velocity of the sailing craft. Angle of attack is often constrained by the sailing craft's orientation to the wind or point of sail. On points of sail where it is possible to align the leading edge of the sail with the apparent wind, the sail may act as an airfoil, generating propulsive force as air passes along its surface—just as an airplane wing generates lift—which predominates over aerodynamic drag retarding forward motion. The more that the angle of attack diverges from the apparent wind as a sailing craft turns downwind, the more drag increases and lift decreases as propulsive forces, until a sail going downwind is predominated by drag forces. Sails are unable to generate propulsive force if they are aligned too closely to the wind.

Sails may be attached to a mast, boom or other spar or may be attached to a wire that is suspended by a mast. They are typically raised by a line, called a halyard, and their angle with respect to the wind is usually controlled by a line, called a sheet. In use, they may be designed to be curved in both directions along their surface, often as a result of their curved edges. Battens may be used to extend the trailing edge of a sail beyond the line of its attachment points.

Other non-rotating airfoils that power sailing craft include wingsails, which are rigid wing-like structures, and kites that power kite-rigged vessels, but do not employ a mast to support the airfoil and are beyond the scope of this article.

Rigs

Main articles: Square rig and Fore-and-aft rig

Sailing craft employ two types of rig, the square rig and the fore-and-aft rig.

The square rig carries the primary driving sails are carried on horizontal spars, which are perpendicular or square, to the keel of the vessel and to the masts. These spars are called yards and their tips, beyond the last stay, are called the yardarms. A ship mainly so rigged is called a square-rigger. The square rig is aerodynamically most efficient when running (sailing downwind).

A fore-and-aft rig consists of sails that are set along the line of the keel rather than perpendicular to it. Vessels so rigged are described as fore-and-aft rigged.

History

Egyptian sailing ship, ca. 1422–1411 BCE

Main article: Ship § History

Archaeological studies of the Cucuteni-Trypillian culture ceramics show use of sailing boats from the sixth millennium BCE onwards. Excavations of the Ubaid period (c. 6000–4300 BCE) in Mesopotamia provides direct evidence of sailing boats.

Square rigs

Sails from ancient Egypt are depicted around 3200 BCE, where reed boats sailed upstream against the River Nile's current. Ancient Sumerians used square rigged sailing boats at about the same time, and it is believed they established sea trading routes as far away as the Indus valley. The proto-Austronesian words for sail, lay(r), and other rigging parts date to about 3000 BCE when this group began their Pacific expansion. Greeks and Phoenicians began trading by ship by around 1200 BCE.

Fore-and-aft rigs

Main articles: Fore-and-aft rig and Lateen

Triangular fore-and-aft rigs were invented in the Mediterranean as single-yarded lateen sails and independently in the Pacific as the more efficient bi-sparred crab claw sail, and continue to be used throughout the world. During the 16th-19th centuries other fore-and-aft sails were developed in Europe, such as the spritsail, gaff rig, jib, genoa, staysail, and Bermuda rig mainsail, improving the upwind sailing ability of European vessels.

The fore-and-aft rig began as a convention of southern Europe and the Mediterranean Sea: the generally gentle climate made its use practical, and in Italy a few centuries before the Renaissance it began to replace the square rig which had dominated all of Europe since the dawn of sea travel. Northern Europeans were resistant to adopting the fore-and-aft rig, despite having seen its use in the course of trade and during the Crusades. The Renaissance changed this: beginning in 1475, their use increased and within a hundred years the fore-and-aft rig was in common use on rivers and in estuaries in Britain, northern France, and the Low Countries, though the square rig remained standard for the harsher conditions of the open North Sea as well as for trans-Atlantic sailing. The lateen sail proved to have better upwind performance for smaller vessels.

Aerodynamic forces

Aerodynamic forces for two points of sail.
Left-hand boat:
Down wind—predominant drag propels the boat with little heeling moment.
Right-hand boat:
Up wind (close-hauled)—predominant lift both propels the boat and contributes to heel.

Sail angles of attack and resulting (idealized) flow patterns that provide propulsive lift.

Main article: Forces on sails

Aerodynamic forces on sails depend on wind speed and direction and the speed and direction of the craft. The direction that the craft is traveling with respect to the true wind (the wind direction and speed over the surface) is called the "point of sail". The speed of the craft at a given point of sail contributes to the apparent wind ( V_A)—the wind speed and direction as measured on the moving craft. The apparent wind on the sail creates a total aerodynamic force, which may be resolved into drag—the force component in the direction of the apparent wind—and lift—the force component normal (90°) to the apparent wind. Depending on the alignment of the sail with the apparent wind, lift or drag may be the predominant propulsive component. Total aerodynamic force also resolves into a forward, propulsive, driving force—resisted by the medium through or over which the craft is passing (e.g. through water, air, or over ice, sand)—and a lateral force, resisted by the underwater foils, ice runners, or wheels of the sailing craft.

For apparent wind angles aligned with the entry point of the sail, the sail acts as an airfoil and lift is the predominant component of propulsion. For apparent wind angles behind the sail, lift diminishes and drag increases as the predominant component of propulsion. For a given true wind velocity over the surface, a sail can propel a craft to a higher speed, on points of sail when the entry point of the sail is aligned with the apparent wind, than it can with the entry point not aligned, because of a combination of the diminished force from airflow around the sail and the diminished apparent wind from the velocity of the craft. Because of limitations on speed through the water, displacement sailboats generally derive power from sails generating lift on points of sail that include close-hauled through broad reach (approximately 40° to 135° off the wind). Because of low friction over the surface and high speeds over the ice that create high apparent wind speeds for most points of sail, iceboats can derive power from lift further off the wind than displacement boats.

Downwind sailing with a spinnaker

• Spinnaker set for a broad reach, mobilizing both lift and drag.

• Spinnaker cross-section trimmed for a broad reach showing air flow.

• Spinnaker downwind, primarily mobilizing drag.

• Spinnaker cross-section with following apparent wind, showing air flow.

Types

Different sail types.

A. Square: Course
B. Square: Topsail
C. Lateen
D. Staysail
E. Gaff-rigged
G. Quadrilateral on spar
H. Loose-footed on gaff
J. Spritsail
K. Standing lug
L. Triangular
M. Dipping lug
N. Junk

See also: Sail plan

Each rig is configured in a sail plan, appropriate to the size of the sailing craft. A sail plan is a set of drawings, usually prepared by a naval architect which shows the various combinations of sail proposed for a sailing ship. Sail plans may vary for different wind conditions—light to heavy. Both square-rigged and fore-and-aft rigged vessels have been built with a wide range of configurations for single and multiple masts.

Types of sail that can be part of a sail plan can be broadly classed by how they are attached to the sailing craft:

• To a stay – Sails attached to stays, include jibs, which are attached to forestays and staysails, which are mounted on other stays (typically wire cable) that support other masts from the bow aft.
• To a mast – Fore-and-aft sails directly attached to the mast at the luff include gaff-rigged quadrilateral and Bermuda triangular sails.
• To a spar – Sails attached to a spar include both square sails and such fore-and-aft quadrilateral sails as lug rigs, junk and spritsails and such triangular sails as the lateen, and the crab claw.
• To a halyard – Spinnakers are the predominant sail supported solely by a halyard.

High-performance yachts, including the International C-Class Catamaran, have used or use rigid wing sails, which perform better than traditional soft sails but are more difficult to manage. A rigid wing sail was used by Stars and Stripes, the defender which won the 1988 America's Cup, and by USA-17, the challenger which won the 2010 America's Cup. USA 17's performance during the 2010 America's Cup races demonstrated a velocity made good upwind of over twice the wind speed and downwind of over 2.5 times the wind speed and the ability to sail as close as 20 degrees off the apparent wind.

Shape

Corners and sides of a quadrilateral fore-and-aft sail

Main article: Sail components § Shape

The shape of a sail is defined by its edges and corners in the plane of the sail, laid out on a flat surface. The edges may be curved, either to extend the sail's shape as an airfoil or to define its shape in use. In use, the sail becomes a curved shape, adding the dimension of depth or draft.

• Edges – The top of all sails is called the head, the leading edge is called the luff on fore-and-aft sails and on windward leech symmetrical sails, the trailing edge is the leech, and the bottom edge is the foot. The head is attached at the throat and peak to a gaff, yard, or sprit. For a triangular sail the head refers to the topmost corner.

A fore-and-aft triangular mainsail achieves a better approximation of a wing form by extending the leech aft, beyond the line between the head and clew on an arc called the roach, rather than having a triangular shape. This added area would flutter in the wind and not contribute to the efficient airfoil shape of the sail without the presence of battens. Offshore cruising mainsails sometimes have a hollow leech (the inverse of a roach) to obviate the need for battens and their ensuing likelihood of chafing the sail. The roach on a square sail design is the arc of a circle above a straight line from clew to clew at the foot of a square sail, which allows the foot of the sail to clear stays coming up the mast, as the sails are rotated from side to side.

• Corners – The names of corners of sails vary, depending on shape and symmetry. In a triangular sail, the corner where the luff and the leech connect is called the head. On a square sail, the top corners are head cringles, where there are grommets, called cringles. On a quadrilateral sail, the peak is the upper aft corner of the sail, at the top end of a gaff or other spar. The throat is the upper forward corner of the sail, at the bottom end of a gaff or other spar. Gaff-rigged sails, and certain similar rigs, employ two halyards to raise the sails: the throat halyard raises the forward, throat end of the gaff, while the peak halyard raises the aft, peak end.

The corner where the leech and foot connect is called the clew on a fore-and-aft sail. On a jib, the sheet is connected to the clew; on a mainsail, the sheet is connected to the boom (if present) near the clew. Clews are the lower two corners of a square sail. Square sails have sheets attached to their clews like triangular sails, but the sheets are used to pull the sail down to the yard below rather than to adjust the angle it makes with the wind. The corner where the leech and the foot connect is called the clew. The corner on a fore-and-aft sail where the luff and foot connect is called the tack and, on a mainsail, is located where the boom and mast connect.

In the case of a symmetrical spinnaker, each of the lower corners of the sail is a clew. However, under sail on a given tack, the corner to which the spinnaker sheet is attached is called the clew, and the corner attached to the spinnaker pole is referred to as the tack. On a square sail underway, the tack is the windward clew and also the line holding down that corner.

• Draft – Those triangular sails that are attached to both a mast along the luff and a boom along the foot have depth, called draft, which results from the luff and foot being curved, rather than straight as they are attached to those spars. Draft creates a more efficient airfoil shape for the sail. Draft can also be induced in triangular staysails by adjustment of the sheets and the angle from which they reach the sails.

Material

Laminated sail with Kevlar and carbon fibers.

Main articles: Sailcloth and Sail components § Materials

Sail characteristics derive, in part, from the 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: initial modulus, breaking strength (tenacity), creep, and flex strength. 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. 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. Woven materials, like Dacron, may specified as either high or low tenacity, as indicated, in part by their denier count (a unit of measure for the linear mass density of fibers).

Construction

Cross-cut genoa jib with sail components.

Main articles: Sail components § Construction, and Sail components § Fittings

Conventional sails comprise panels, which are most often stitched together, 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 least 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 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.

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.

Higher-performance sails may be laminated, constructed directly from multiple plies of filaments, fibers, taffetas, and 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.

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.

Whereas textiles are typically sewn together, other sail materials may be ultrasonically welded—a technique whereby high-frequency ultrasonic acoustic vibrations are locally applied to workpieces being held together under pressure to create a solid-state weld. It is commonly used for plastics, and especially for joining dissimilar materials.

Sails feature reinforcements of fabric layers where lines attach at grommets or cringles. A bolt rope may be sewn onto the edges of a sail to reinforce it, or to fix the sail into a groove in the boom, in the mast, or in the luff foil of a roller-furling jib. They may have stiffening features, called battens, that help shape the sail, when full length, or just the roach, when present. They may have a variety of means of reefing them (reducing sail area), including rows of short lines affixed to the sail to wrap up unused sail, as on square and gaff rigs, or simply grommets through which a line or a hook may pass, as on Bermuda mainsails. Fore-and-aft sails may have tell-tales—pieces of yarn, thread or tape that are affixed to sails—to help visualize airflow over their surfaces.

Running rigging

Running rigging on a sailing yacht:
1. Main sheet
2. Jib sheet
3. Boom vang
4. Downhaul
5. Jib halyard

Square sail edges and corners (top). Running rigging (bottom).

Main article: Running rigging

The lines that attach to and control sails are part of the running rigging and differ between square and fore-and-aft rigs. Some rigs shift from one side of the mast to the other, e.g. the dipping lug sail and the lateen. The lines can be categorized as those that support the sail, those that shape it, and those that control its angle to the wind.

Fore-and-aft rigged vessels

Fore-and-aft rigged vessels have rigging that supports, shapes, and adjusts the sails to optimize their performance in the wind, which include the following lines:

• Supporting – Halyards raise sails and control luff tension. Topping lifts hold booms and yards aloft. On a gaff sail, brails run from the leech to the spar to facilitate furling.
• Shaping – Barber haulers adjust a spinnaker/jib sheeting angle inboard at right angles to the sheet with a ring or clip on the sheet attached to cordage which is secured and adjusted via fairlead and cam cleat. Kicking straps/boom vangs control a boom-footed sail's leech tension by exerting downward force mid-boom. Cunninghams tighten the luff of a boom-footed sail by pulling downward on a cringle in the luff of a mainsail above the tack. Downhauls lower a sail or a yard and can adjust the tension on the luff of a sail. Outhauls control the foot tension of a boom-footed sail.
• Adjusting angle to the wind – Sheets control angle of attack with respect to the apparent wind, the amount of leech "twist" near the head of the sail, and the foot tension of loose-footed sails. A preventer attaches to the end of the boom from a point near the mast to prevent an accidental gybe. Guys control spinnaker pole angle with respect to the apparent wind.

Square-rigged vessels

Square-rigged vessels require more controlling lines than fore-and-aft rigged ones, including the following.

• Supporting – Halyards raise and lower the yards. Brails run from the leech to the spar to facilitate furling. Buntlines serve to raise the foot up for shortening sail or for furling. Lifts adjust the tilt of a yard, to raise or lower the ends off the horizontal. Leechlines run to the leech (outer vertical edges) of a sail and serve to pull the leech both in and up when furling.
• Shaping – Bowlines run from the leech forward towards the bow to control the weather leech, keeping it taut and thus preventing it from curling back on itself. Clewlines raise the clews to the yard above.
• Adjusting angle to the wind – Braces adjust the fore and aft angle of a yard (i.e. to rotate the yard laterally, fore and aft, around the mast). Sheets attach to the clew to control the sail's angle to the wind. Tacks haul the clew of a square sail forward.

Gallery

Sails on high-performance sailing craft.

• International Moth on foils.

• Windsurfer.

• Formula 16 catamaran.

• DN class ice boat.

• Land sailing craft.

Sails on craft subject to low forward resistance and high lateral resistance.

See also

Components

• Marine canvas
• Sail Class Markings
• Baggywrinkle

Concepts

• Sail twist

Related

• Cruising (maritime)

Types of sails

• Mainsail
• Mizzen

Further reading

• Rousmaniere, John. The Annapolis Book of Seamanship. Simon & Schuster, 1999.
• Chapman Book of Piloting (various contributors), Hearst Corporation, 1999.
• Marino, Emiliano. The Sailmaker's Apprentice. International Marine, 1994.
• Herreshoff, Halsey (consulting editor). The Sailor’s Handbook. Little Brown and Company, 1983.
• Seidman, David. The Complete Sailor. International Marine, 1995.
• Jobson, Gary. Sailing Fundamentals. Simon & Schuster, 1987.
• Marchaj, Czeslaw A. Sail Performance, Techniques to Maximize Sail Power, Revised edition. London: Adlard Coles Nautical, 2003.
• Crothers, William L. (2014). The Masting of American Merchant Sail in the 1850s An Illustrated Study. Jefferson, North Carolina: McFarland Publishing. ISBN 9780786493999.

External links

• Sailboats database: sailing yacht specifications worldwide
• Sail Design Software
• The quest for the perfect sailshape
• FABRIC Sail Design Software
• Laminated Sails: Doyle Stratis
•  "Sail" . The New Student's Reference Work . 1914.

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 小児における肘関節の解剖学的構造および肘関節骨折の放射線学的診断 elbow anatomy and radiographic diagnosis of elbow fracture in children
• 2. 新生児における肺のエアリーク pulmonary air leak in the newborn
• 3. エブスタイン奇形の臨床症状と診断 clinical manifestations and diagnosis of ebstein anomaly
• 4. 骨折のマネージメントの一般原則：小児における骨折のパターンおよび種類 general principles of fracture management fracture patterns and description in children
• 5. 成人における橈骨頭および橈骨頚部の骨折 radial head and neck fractures in adults

English Journal

• The long-term direct and indirect economic burden among Parkinson's disease caregivers in the United States.

• Martinez-Martin P1, Macaulay D2, Jalundhwala YJ3, Mu F4, Ohashi E4, Marshall T3, Sail K3.
• Movement disorders : official journal of the Movement Disorder Society.Mov Disord.2018 Dec 27. doi: 10.1002/mds.27579. [Epub ahead of print]
• PMID 30589953

• HcCUB-Lec, a newly identified C-type lectin that contains a distinct CUB domain and participates in the immune defense of the triangle sail mussel Hyriopsis cumingii.

• Huang Y1, Ren Q2.
• Developmental and comparative immunology.Dev Comp Immunol.2018 Dec 25;93:66-77. doi: 10.1016/j.dci.2018.12.012. [Epub ahead of print]
• PMID 30590065

• Association of Hospital Employee Satisfaction with Patient Safety and Satisfaction within Veterans Affairs Medical Centers.

• Kang R1, Kunkel ST2, Columbo JA1, Goodney PP3, Wong SL4.
• The American journal of medicine.Am J Med.2018 Dec 20. pii: S0002-9343(18)31158-6. doi: 10.1016/j.amjmed.2018.11.031. [Epub ahead of print]
• PMID 30579740

• Developing consensus among movement disorder specialists on clinical indicators for identification and management of advanced Parkinson's disease: a multi-country Delphi-panel approach.

• Antonini A1, Stoessl AJ2, Kleinman LS3, Skalicky AM3, Marshall TS4, Sail KR4, Onuk K4, Odin PLA5,6.
• Current medical research and opinion.Curr Med Res Opin.2018 Dec;34(12):2063-2073. doi: 10.1080/03007995.2018.1502165. Epub 2018 Aug 20.
• PMID 30016901

Japanese Journal

• インドネシア帆走練習艦「ビマ・スーチ」来日!

• 世界の艦船 (911), 117-119, 2019-11
• NAID 40022027927

• Topics from special edition 高分子量蛋白質の溶液NMR解析法の開発

• 宮ノ入 洋平,武田 光広,寺内 勉,甲斐荘 正恒
• 細胞 51(12), 619-622, 2019-10
• NAID 40022083993

• ゼロエミッション帆船の概念設計

• 大内 一之
• 日本船舶海洋工学会講演会論文集 Conference proceedings, the Japan Society of Naval Architects and Ocean Engineers (28), 193-195, 2019-06
• NAID 40022064629

Related Links

• sailの意味・使い方｜英辞郎 on the WEB：アルク

《海事》詰め開きで帆走 ｛はんそう｝ する 危険なほど風上に向けて走行すること。【表現パターン】 sail close [near] to the wind 危険 ｛きけん｝ を冒す、冒険 ｛ぼうけん｝ をする 【表現パターン】 sail close [near] to the wind

• Sail (セイル) - 海外の方々と日本語で異文化交流をしよう

Sail (セイル) は、日本の皆さんが、日本語を使いながら、国も世代も違う海外の人々と異文化交流を楽しむサービスです ...

• sailの意味 - 英和辞典 - コトバンク

1 （船の）帆；((集合的に複数扱い))（一隻または数隻の）帆 put up [＝hoist] a sail 帆を揚げる haul down [＝lower] a sail 帆を降ろす pack on all sail 帆をすべて上げる, 満帆を張る a ship in full sail 帆を全部揚げた ...

Related Pictures

---

★リンクテーブル★

拡張検索	「sailor knot」「sailor's knot」

「sailor knot」

　　[★] 男結び。舟夫結節 船頭結び

「sailor's knot」

　　[★] 男結び。舟夫結節 船頭結び