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Luffing (crane)
In sailing, luffing refers to when a sailing vessel is steered far enough toward the direction of the wind ("windward"), or the sheet controlling a sail is eased so far past optimal trim, that airflow over the surfaces of the sail is disrupted and the sail begins to "flap" or "luff" (the luff of the sail is usually where this first becomes evident). This is not always done in error; for example, the sails will luff when the bow of the boat passes through the direction of the wind as the sailboat is tacked. A sailboat can also be "luffed" slightly without completely de-powering the sails. Often this occurs on the point of sail known as close hauled, this is sometimes referred to as pinching or "feathering" and is sometimes done deliberately in order to make a more direct course toward an upwind destination (see: " beating to windward"), or to "de-power" a sail on a windy day to maintain control of the sailboat. "Luffing" can also be used to slow or stop a sailboat in a con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sailing
Sailing employs the wind—acting on sails, wingsails or kites—to propel a craft on the surface of the ''water'' (sailing ship, sailboat, raft, Windsurfing, windsurfer, or Kitesurfing, kitesurfer), on ''ice'' (iceboat) or on ''land'' (Land sailing, land yacht) over a chosen Course (navigation), course, which is often part of a larger plan of navigation. From prehistory until the second half of the 19th century, sailing craft were the primary means of maritime trade and transportation; exploration across the seas and oceans was reliant on sail for anything other than the shortest distances. Naval power in this period used sail to varying degrees depending on the current technology, culminating in the gun-armed sailing warships of the Age of Sail. Sail was slowly replaced by steam as the method of propulsion for ships over the latter part of the 19th century – seeing a gradual improvement in the technology of steam through a number of developmental steps. Steam allowed schedul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Windward
In geography and seamanship, windward () and leeward () are directions relative to the wind. Windward is ''upwind'' from the point of reference, i.e., towards the direction from which the wind is coming; leeward is ''downwind'' from the point of reference, i.e., along the direction towards which the wind is going. The side of a ship that is towards the leeward is its "lee side". If the vessel is heeling under the pressure of crosswind, the lee side will be the "lower side". During the Age of Sail, the term ''weather'' was used as a synonym for ''windward'' in some contexts, as in the '' weather gage''. Since it captures rainfall, the windward side of a mountain tends to be wetter than the leeward side it blocks. The drier leeward area is said to be in a rain shadow. Origin The term "windward" has roots in both Low German and Old English. The word "lee", which means a place without wind, comes from the Old Norse "hle" for "cover" and has been used in marine navigation ... [...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] |
Parts Of A Sail
Sail components include the features that define a sail's shape and function, plus its constituent parts from which it is manufactured. A sail may be classified in a variety of ways, including by its orientation to the vessel (e.g. ''fore-and-aft'') and its shape, (e.g. ''(a)symmetrical'', ''triangular'', ''quadrilateral'', etc.). Sails are typically constructed out of flexible material that is shaped by various means, while in use, to offer an appropriate airfoil, according to the strength and apparent direction of the wind. A variety of features and fittings allow the sail to be attached to lines and spars. Whereas conventional sails form an airfoil with one layer of fabric, wingsails comprise a structure that has material on both sides to form an airfoil—much like a wing placed vertically on the vessel—and are beyond the scope of this article. Classifications Sails may be classified as either ''triangular'', which describes sails that either come to one point of suspen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tack (sailing)
A tack is the windward side of a sailing craft (side from which the wind is coming while under way)—the starboard or port tack. Generally, a craft is on a starboard tack if the wind is coming over the starboard (right) side with sails on port (left) side. Similarly, a craft is on a port tack if the wind is coming over the port (left). Tack is also a nautical term both for the lower, windward corner of a sail. Windward side of course sailed As a point of reference, tack is the alignment of the wind with respect to a sailing craft under way. If the wind is from the starboard side of the sailing craft, it is on ''starboard tack'', and if from port, on ''port tack''. The International Regulations for Preventing Collisions at Sea for vessels underway declare that when the courses of two sailing vessels converge, the vessel on ''port tack'' must give way to a vessel on ''starboard tack''. The maneuver of changing a sailing craft's course from one tack to the other during which t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Points Of Sail
A point of sail is a sailing craft's Course (navigation), direction of travel under sail in relation to the true wind direction over the surface. The principal points of sail roughly correspond to 45° segments of a circle, starting with 0° directly into the wind. For many sailing craft 45° on either side of the wind is a ''no-go'' zone, where a sail is unable to mobilize power from the wind. Sailing on a course as close to the wind as possible—approximately 45°—is termed ''beating'', a point of sail when the sails are ''close-hauled''. At 90° off the wind, a craft is on a ''beam reach''. The point of sail between beating and a beam reach is called a ''close reach''. At 135° off the wind, a craft is on a ''broad reach''. At 180° off the wind (sailing in the same direction as the wind), a craft is ''running downwind''. A given point of sail (beating, close reach, beam reach, broad reach, and running downwind) is defined in reference to the #True wind versus apparent win ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tacking (sailing)
Tacking or coming about is a sailing maneuver by which a sailing craft ( sailing vessel, ice boat, or land yacht), whose next destination is into the wind, turns its bow toward and through the wind so that the direction from which the wind blows changes from one side of the boat to the other, allowing progress in the desired direction. Sailing vessels are unable to sail higher than a certain angle towards the wind, so "beating to windward" in a zig-zag fashion with a series of tacking maneuvers, allows a vessel to sail towards a destination that is closer to the wind than the vessel can sail directly. A sailing craft whose course is downwind jibes (or "wears" if square-rigged) by having the apparent wind cross the stern from one tack to the other. High-performance sailing craft may tack, rather than jibe, downwind, when the apparent wind is well forward. Beating to windward Sails are limited in how close to the direction of the wind they can power a sailing craft. The ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Kite
A power kite or traction kite is a large kite designed to provide significant pull to the user. Types The two most common forms are the foil, and the leading edge inflatable. There are also other less common types of power kite including rigid-framed kites and soft single skin kites. There are several different control systems used with these kites which have two to five lines and a bar or handles. Foil kites consist of a number of cells with cloth ribs in each cell. It is the profile of these ribs that gives the kite its aerofoil shape and enable it to generate lift. The most common type is the ram-air foil, where each cell has a gauze-covered opening at the front, meaning air is forced in during flight, giving the kite its stiffness and enabling it to hold its profile. Some ram-air foils are closed-cell, where a one-way valve locks the air inside the cells, giving some increased water relaunch capability. Leading edge inflatable kites (LEIs) are made of a single skin of f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
