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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 ...
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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, windsurfer, or kitesurfer), on ''ice'' (iceboat) or on ''land'' (land yacht) over a chosen 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 stepwise developments. Steam allowed scheduled services that ran at higher average speeds than sail ...
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Reefing
Reefing reduces the area of a sail, usually by folding or rolling one edge of the canvas in on itself and attaching the unused portion to a spar or a stay, as the primary measure to preserve a sailing vessel's stability in strong winds. Restoring full sail area is termed ''shaking out'' a reef. Whereas fore-and-aft rigged vessels store the unused portion of the sail on a boom, below the sail, square-rigged vessels stow the unused portion on a spar, above the sail. Reefing may occur by rolling the sail around its luff or foot, either on a rotating stay or within a spar. Fore-and-aft rigs Sails may have built-in alternative attachment points that allow their area to be reduced. In a mainsail, pairs of grommets, called reefing tacks, reefing clews, or reefing cringles may be installed in the sail; a cruising boat will typically have two to three pairs. Pulling these points down to the boom forms a new tack and clew, reducing the sail's area. Using the pair of grommets closest t ...
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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 ...
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Rope
A rope is a group of yarns, plies, fibres, or strands that are twisted or braided together into a larger and stronger form. Ropes have tensile strength and so can be used for dragging and lifting. Rope is thicker and stronger than similarly constructed cord, string, and twine. Construction Rope may be constructed of any long, stringy, fibrous material, but generally is constructed of certain natural or synthetic fibres. Synthetic fibre ropes are significantly stronger than their natural fibre counterparts, they have a higher tensile strength, they are more resistant to rotting than ropes created from natural fibres, and they can be made to float on water. But synthetic ropes also possess certain disadvantages, including slipperiness, and some can be damaged more easily by UV light. Common natural fibres for rope are Manila hemp, hemp, linen, cotton, coir, jute, straw, and sisal. Synthetic fibres in use for rope-making include polypropylene, nylon, polyesters (e.g. ...
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Yardarm
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 vesse ...
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Gasket Coil
Some seals and gaskets A gasket is a mechanical seal which fills the space between two or more mating surfaces, generally to prevent leakage from or into the joined objects while under compression. It is a deformable material that is used to create a static seal and maintain that seal under various operating conditions in a mechanical assembly. Gaskets allow for "less-than-perfect" mating surfaces on machine parts where they can fill irregularities. Gaskets are commonly produced by cutting from sheet materials. Given the potential cost and safety implications of faulty or leaking gaskets, it is critical that the correct gasket material is selected to fit the needs of the application. Gaskets for specific applications, such as high pressure steam systems, may contain asbestos. However, due to health hazards associated with asbestos exposure, non-asbestos gasket materials are used when practical. It is usually desirable that the gasket be made from a material that is to some deg ...
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Slippery Hitch
A slippery hitch is a knot used to attach a line to a rod or bar. It does not provide great strength compared to some other knots, but it can be tied relatively quickly and released very easily. These characteristics mean that it is used on square-rigged ships for securing the gaskets that bind stowed sails to the yards. The slippery hitch is effectively a clove hitch finished with a slipped loop. To tie one, begin as for a clove hitch, but instead of passing the end of the line through the loop in the final step, pass a bight instead, leaving the end on the original side. Pulling on this end will release the hitch. If tied in a gasket, this will quickly release the sail. See also *List of knots This list of knots includes many alternative names for common knots and lashings. Knot names have evolved over time, and there are many conflicting or confusing naming issues. The overhand knot, for example, is also known as the thumb knot. The ...
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Clove Hitch
The clove hitch is a type of knot. Along with the bowline and the sheet bend, it is often considered one of the most important knots. A clove hitch is two successive half-hitches around an object. It is most effectively used as a crossing knot. It can be used as a binding knot, but is not particularly secure in that role. A clove hitch made around the rope's own standing part is known as either two half-hitches or buntline hitch, depending on whether the turns of the clove hitch progress away from or towards the hitched object. Usage This knot is particularly useful where the length of the running end needs to be adjustable, since feeding in rope from either direction will loosen the knot to be tightened at a new position. With certain types of cord, the clove hitch can slip when loaded. In modern climbing rope, the clove hitch will slip to a point, and then stop slipping. When tied around a carabiner, the load should pull on the end closest to its spine. With smaller ...
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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 ...
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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 ...
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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 ...
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