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Clewlines And Buntlines
Clewlines and buntlines are lines used to handle the sails of a square rigged ship. Although the common perception of a traditionally rigged ship is that the sails are handled from "up in the rigging", the majority of the work is actually carried out from the deck. In particular, when sailors go aloft to stow the square sails by bundling them up and tying them to the yard (with gaskets) they don't have to pull the whole weight of the sail up towards them. That work has already been carried out from the deck using the clewlines and the buntlines. As the name suggests, clewlines are attached to the outer corners or clews of the sail. They lift more weight than the buntlines, and also have to pull against the sheets - although these will have been released there is still a certain amount of friction produced by the blocks and fairleads that they run through. For this reason the clewlines are usually fitted with blocks to increase the mechanical advantage. The clewlines are colour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sail
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 p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Rig
Square rig is a generic type of sail and rigging arrangement in which 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, outside the lifts, are called the ''yardarms.'' A ship mainly rigged so is called a square-rigger. The square rig is aerodynamically the most efficient running rig (i.e., sailing downwind), and stayed popular on ocean-going sailing ships until the end of the Age of Sail. The last commercial sailing ships, windjammers, were usually square-rigged four-masted barques. History The oldest archaeological evidence of use of a square-rig on a vessel is an image on a clay disk from Mesopotamia from 5000 BC. 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 be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yard (sailing)
A yard is a spar on a 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. ; 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 around the mast to allow the direction of the vess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gasket (sailing)
In sailing, gaskets are lengths of rope or fabric used for reefing a sail, or hold a stowed sail in place. In modern use, the term is usually restricted to square-rigged ships, the equivalent items on yachts being referred to by the more prosaic "sail ties". On most ships, gaskets are made of rope. They are attached to the top of the yard and, left loose, would hang behind the sail. Gaskets should never be left dangling, however, so when the sail is set they are brought around underneath the yard and up the back of it and then tied to the jackstay (metal rod) where they originated. Alternatively, longer gaskets - particularly the clew gaskets described below - can be secured using a gasket coil. When the sail is to be stowed it is first folded and bagged neatly within itself, pulled onto the top of the yard, and then the gaskets are brought round over it and secured to the jackstay to hold it in place. Gaskets should be tied with a slippery hitch to enable them to be let off quickl ... [...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] |
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 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fairlead
A fairlead is a device to guide a line, rope or cable around an object, out of the way or to stop it from moving laterally. Typically a fairlead will be a ring or hook. The fairlead may be a separate piece of hardware, or it could be a hole in the structure. There are two types of fairlead: roller and fixed. In a roller fairlead, there are four rollers in total. The first two are vertically mounted and the other two are horizontally mounted. A fixed fairlead is one piece of smooth, rounded metal with no moving parts. A fixed fairlead may be open or closed. Compared to a roller fairlead, a fixed fairlead is extremely simple. A fairlead can also be used to stop a straight run of line from vibrating or rubbing on another surface. An additional use on boats is to keep a loose end of line from sliding around the deck (''e.g.'' the windward (inactive) jib Sheet (sailing), sheet). If the line is meant to be moved while in the fairlead, the angle in the line created by the fairlead mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Block (sailing)
In sailing, a block is a single or multiple pulley. One or a number of ''sheaves'' are enclosed in an assembly between ''cheeks'' or ''chocks''. In use, a block is fixed to the end of a line, to a spar (sailing), spar, or to a surface. A line (rope) is ''reeved'' through the sheaves, and maybe through one or more matching blocks at some far end, to make up a Block and tackle, tackle. The ''purchase'' of a tackle refers to its mechanical advantage. In general the more sheaves in the blocks that make up a tackle, the higher its mechanical advantage. The matter is slightly complicated by the fact that every tackle has a ''working end'' where the final run of rope leaves the last sheave. More mechanical advantage can be obtained if this end is attached to the moving load rather than the fixed end of the tackle. There are various types of blocks that are used in sailing. Some blocks are used to increase mechanical advantage and others are used simply to change the direction of a li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Advantage
Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for this is the ''law of the lever.'' Machine components designed to manage forces and movement in this way are called mechanisms. An ideal mechanism transmits power without adding to or subtracting from it. This means the ideal machine does not include a power source, is frictionless, and is constructed from rigid bodies that do not deflect or wear. The performance of a real system relative to this ideal is expressed in terms of efficiency factors that take into account departures from the ideal. Lever The lever is a movable bar that pivots on a fulcrum attached to or positioned on or across a fixed point. The lever operates by applying forces at different distances from the fulcrum, or pivot. The location of the fulcrum determines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buntline Hitch
The buntline hitch is a knot used for attaching a rope to an object. It is formed by passing the working end around an object, then making a clove hitch around the rope's standing part and taking care that the turns of the clove hitch progress ''towards'' the object rather than away from it. Secure and easily tied, the buntline hitch will jam when subjected to extreme loads. Given the knot's propensity to jam, it is often made in slipped form. History Simple and effective, the buntline hitch dates to the age of sail, when it was used to secure buntlines to the foot of the sailsBrion Toss, ''Chapman's Nautical Guides: Knots'' (New York: Hearst Marine Books, 1990), 39.Clifford W. Ashley, ''The Ashley Book of Knots'' (New York: Doubleday, 1944), 310. on square-rigged ships. That the buntline hitch was the preferred knot speaks to its security and reliability.Geoffrey Budworth, ''The Complete Book of Knots'' (London: Octopus, 1997), 51. Once set, repeated jerking and slatting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
