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Sail ALOmari
A sail is a tensile structure, which is 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Rig
Square rig is a generic type of sail plan, sail and rigging arrangement in which a sailing ship, sailing vessel's primary driving sails are carried on horizontal spar (sailing), spars that are perpendicular (or wikt:square#Adjective, square) to the median plane of the keel and masts of the vessel. These spars are called and their tips, outside the lifts, are called the . A ship mainly rigged so is called a square-rigger. In "customs and traditions of the Royal Navy, Jackspeak" (Royal Navy slang), it also refers to the uniforms of the Royal Navy, dress uniform of Junior Ratings. History Single sail square rigs were used by the ancient Egyptians, the Phoenicians, the Greeks, the Romans, and the Celts. Later the Scandinavians, the Germanic peoples, and the Slavs adopted the single square-rigged sail, with it becoming one of the defining characteristics of the classic “Viking” ships.The Viking ship's single square-rigged sail. http://Longshipco.org/sail.html Retrieved 2018-8- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodynamic Drag
In fluid dynamics, drag, sometimes referred to as fluid resistance, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, two solid surfaces, or between a fluid and a solid surface. Drag forces tend to decrease fluid velocity relative to the solid object in the fluid's path. Unlike other resistive forces, drag force depends on velocity. Drag force is proportional to the relative velocity for low-speed flow and is proportional to the velocity squared for high-speed flow. This distinction between low and high-speed flow is measured by the Reynolds number. Drag is instantaneously related to vorticity dynamics through the Josephson-Anderson relation. Examples Examples of drag include: * Net force, Net Aerodynamic force, aerodynamic or Fluid dynamics, hydrodynamic force: Drag acting opposite to the direction of movement of a solid object such as cars, aircraft, and boat hulls. * Viscou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yard (sailing)
A yard is a spar (sailing), spar on a mast (sailing), mast from which sails are set. It may be constructed of timber or steel or from more modern materials such as aluminium or carbon fibre. Although some types of fore and aft rigs have yards, the term is usually used to describe the horizontal spars used on square rigged sails. In addition, for some decades after square sails were generally dispensed with, some yards were retained for deploying wireless (radio) aerials and signal flags. Parts of the yard ; Bunt : The short section of the yard between the ''slings'' that attach it to the mast. ; Quarters : The port and starboard quarters form the bulk of the yard, extending from the slings to the fittings for the lifts and braces (sailing), braces. ; Yardarms : The outermost tips of the yard: outboard from the attachments for the lifts. Note that these terms refer to stretches of the same spar, not to separate component parts. Controlling the yard The yard can rotate aro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keel
The keel is the bottom-most longitudinal structural element of a watercraft, important for stability. On some sailboats, it may have a fluid dynamics, hydrodynamic and counterbalancing purpose as well. The keel laying, laying of the keel is often the initial step in constructing a ship. In the British and American shipbuilding traditions, this event marks the beginning date of a ship's construction. Etymology The word "keel" comes from Old English language, Old English , Old Norse , = "ship" or "keel". It has the distinction of being regarded by some scholars as the first word in the English language recorded in writing, having been recorded by Gildas in his 6th century Latin work ''De Excidio et Conquestu Britanniae'', under the spelling ''cyulae'' (he was referring to the three ships that the Saxons first arrived in). is the Latin word for "keel" and is the origin of the term careening, careen (to clean a keel and the hull in general, often by rolling the ship on its side). An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square
In geometry, a square is a regular polygon, regular quadrilateral. It has four straight sides of equal length and four equal angles. Squares are special cases of rectangles, which have four equal angles, and of rhombuses, which have four equal sides. As with all rectangles, a square's angles are right angles (90 degree (angle), degrees, or Pi, /2 radians), making adjacent sides perpendicular. The area of a square is the side length multiplied by itself, and so in algebra, multiplying a number by itself is called square (algebra), squaring. Equal squares can tile the plane edge-to-edge in the square tiling. Square tilings are ubiquitous in tiled floors and walls, graph paper, image pixels, and game boards. Square shapes are also often seen in building floor plans, origami paper, food servings, in graphic design and heraldry, and in instant photos and fine art. The formula for the area of a square forms the basis of the calculation of area and motivates the search for methods for s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spar (sailing)
A spar is a pole of wood, metal or lightweight materials such as carbon fibre used in the rigging of a sailing vessel to carry or support its sail. These include yards, booms, and masts, which serve both to deploy sail and resist compressive and bending forces, as well as the bowsprit and spinnaker pole. In larger vessels during the age of sail, spare spars could be roped together to provide a temporary surface known as a "spar deck". These served as jury-rigged repairs for permanent decks, or as an additional platform under which to shelter goods or crew. The term was also informally applied to areas of the forecastle The forecastle ( ; contracted as fo'c'sle or fo'c's'le) is the upper deck (ship), deck of a sailing ship forward of the foremast, or, historically, the forward part of a ship with the sailors' living quarters. Related to the latter meaning is t ... or quarterdeck where spare spars were stored by laying them flat against the existing decking. In the moder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fore-and-aft Rig
A fore-and-aft rig is a sailing ship rig with sails set mainly in the median plane of the keel, rather than perpendicular to it, as on a square-rigged vessel. Description Fore-and-aft rigged sails include staysails, Bermuda rigged sails, gaff rigged sails, gunter rig, lateen sails, lug sails, tanja sails, the spanker sail on a square rig, and crab claw sails. Fore-and-aft rigs include: * Rigs with one mast: the proa, the catboat, the sloop, the cutter * Rigs with two masts: the ketch, the yawl * Rigs with two or more masts: the schooner Barques and barquentines are partially square rigged and partially fore-and-aft rigged. A rig which combines both on a foremast is known as a hermaphroditic rig. History Austronesia The fore-and-aft rig is believed to have been developed independently by the Austronesian peoples some time after 1500 BC with the invention of the crab claw sail. It is suggested that it evolved from a more primitive V-shaped "square" sail wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Rig
Square rig is a generic type of sail plan, sail and rigging arrangement in which a sailing ship, sailing vessel's primary driving sails are carried on horizontal spar (sailing), spars that are perpendicular (or wikt:square#Adjective, square) to the median plane of the keel and masts of the vessel. These spars are called and their tips, outside the lifts, are called the . A ship mainly rigged so is called a square-rigger. In "customs and traditions of the Royal Navy, Jackspeak" (Royal Navy slang), it also refers to the uniforms of the Royal Navy, dress uniform of Junior Ratings. History Single sail square rigs were used by the ancient Egyptians, the Phoenicians, the Greeks, the Romans, and the Celts. Later the Scandinavians, the Germanic peoples, and the Slavs adopted the single square-rigged sail, with it becoming one of the defining characteristics of the classic “Viking” ships.The Viking ship's single square-rigged sail. http://Longshipco.org/sail.html Retrieved 2018-8- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kite Rig
Kite rigs are wind-assisted propulsion systems for propelling a vehicle. They differ from conventional sails in that they are flown from kite control lines, not supported by masts. Vehicles driven by kites include boats, buggies, and vehicles with snow and ice runners. They may be as simple as a person flying a kite while standing on a specialized skateboard, or be large, complex systems fixed to the vehicle, with powered and automated controls. They have recreational and commercial uses. Structure Current kite rigs can be sailed within 50 degrees of the wind.Skysails Captain John Konrad, Mariner's Weather Log, April 2009, Volume 53, No. 1, This allows them to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kite
A kite is a tethered heavier than air flight, heavier-than-air craft with wing surfaces that react against the air to create Lift (force), lift and Drag (physics), drag forces. A kite consists of wings, tethers and anchors. Kites often have a bridle and tail to guide the face of the kite so the wind can lift it. Some kite designs do not need a bridle; box kites can have a single attachment point. A kite may have fixed or moving anchors that can balance the kite. The name is derived from the kite (bird), kite, the hovering bird of prey. There are several shapes of kites. The Lift (force), lift that sustains the kite in flight is generated when air moves around the kite's surface, producing low pressure above and high pressure below the wings. The interaction with the wind also generates horizontal Drag (physics), drag along the direction of the wind. The resultant force vector from the lift and drag force components is opposed by the tension of one or more of the rope, lines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sail Batten
On sailboats, a sail batten is a flexible insert in a sail, parallel to the direction of wind flow, that helps shape its qualities as an airfoil. Battens are long, thin strips of material, historically wooden but today usually fiberglass, vinyl, or carbon fiber, used to support the roach of a sail. They are also used on tall ships to form the ladders up the shrouds in a fashion similar to ratlines. History Battened sails are commonly found in junk ship. A junk is an ancient Chinese sailing ship design that is still in use today. Iconographic remains show that Chinese ships before the 12th century used square sails. A ship carving from a stone Buddhist stele shows a ship with square sail from the Liu Sung dynasty or the Liang dynasty (ca. 5th or 6th century). Dunhuang cave temple no. 45 (from the 8th or 9th century) features large sailboats and sampans with inflated square sails. A wide ship with a single sail is depicted in the Xi'an mirror (after the 9th or 12th centu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheet (sailing)
In sailing, a sheet is a line (rope, cable or chain) used to control the movable corner(s) (clews) of a sail. Terminology In nautical usage the term "sheet" is applied to a line or chain attached to the lower corners of a sail for the purpose of extension or change of direction. The connection in derivation with the root "shoot" is more clearly seen in "sheet-anchor", one that is kept in reserve, to be "shot" in case of emergency. Fore-and-aft rigs Fore-and-aft rigs comprise the vast majority of sailing vessels in use today, including effectively all dinghies and yachts. The sheet on a fore-and-aft sail controls the angle of the sail to the wind, and should be adjusted to keep the sail just filled. Most smaller boats use the Bermuda rig, which has two or three sets of sheets: * The mainsheet is attached to the boom, and is used to control the mainsail. In a rig with no boom on the mainsail, the mainsheet would attach directly to the mainsail clew. A mainsheet is a line con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
