Mechanical Traveller

	Mechanical Traveller A traveller is a part of the rigging of a boat or ship that provides a moving attachment point for a rope, sail or yard to a fixed part of the vessel. It may take the form of anything from a simple ring on a metal bar or a spar to, especially in a modern yacht, a more complex "car" – a component with bearing-mounted wheels running on a shaped aluminium extrusion. There are three common examples of the use of a traveller. The sheet of a sail is attached to a traveller on the horse, allowing the sail's clew to be positioned to leeward on each tack, thereby giving a more aerodynamically efficient position of the sail. A jib may be attached to a bowsprit with a traveller. This allows the sail to be set and handed without having to go out onto the bowsprit. Lastly, the yard of a lugsail is usually attached to the mast using a traveller. This often consists of a metal ring around the mast with a hook above and below the ring for, respectively, the halyard and the yard to fasten. A tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Traveller (sailing) A traveller is a part of the rigging of a boat or ship that provides a moving attachment point for a rope, sail or yard to a fixed part of the vessel. It may take the form of anything from a simple ring on a metal bar or a spar to, especially in a modern yacht, a more complex "car" – a component with bearing-mounted wheels running on a shaped aluminium extrusion. There are three common examples of the use of a traveller. The sheet of a sail is attached to a traveller on the horse, allowing the sail's clew to be positioned to leeward on each tack, thereby giving a more aerodynamically efficient position of the sail. A jib may be attached to a bowsprit with a traveller. This allows the sail to be set and handed without having to go out onto the bowsprit. Lastly, the yard of a lugsail is usually attached to the mast using a traveller. This often consists of a metal ring around the mast with a hook above and below the ring for, respectively, the halyard and the yard to fasten. A tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	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]
picture info	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]
picture info	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]
picture info	Tension (mechanics) In physics, tension is described as the pulling force transmitted axially by the means of a string, a rope, chain, or similar object, or by each end of a rod, truss member, or similar three-dimensional object; tension might also be described as the action-reaction pair of forces acting at each end of said elements. Tension could be the opposite of compression. At the atomic level, when atoms or molecules are pulled apart from each other and gain potential energy with a restoring force still existing, the restoring force might create what is also called tension. Each end of a string or rod under such tension could pull on the object it is attached to, in order to restore the string/rod to its relaxed length. Tension (as a transmitted force, as an action-reaction pair of forces, or as a restoring force) is measured in newtons in the International System of Units (or pounds-force in Imperial units). The ends of a string or other object transmitting tension will exert forces on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Deck (ship) A deck is a permanent covering over a compartment or a hull of a ship. On a boat or ship, the primary or upper deck is the horizontal structure that forms the "roof" of the hull, strengthening it and serving as the primary working surface. Vessels often have more than one level both within the hull and in the superstructure above the primary deck, similar to the floors of a multi-storey building, that are also referred to as decks, as are certain compartments and decks built over specific areas of the superstructure. Decks for some purposes have specific names. Structure The main purpose of the upper or primary deck is structural, and only secondarily to provide weather-tightness and support people and equipment. The deck serves as the lid to the complex box girder which can be identified as the hull. It resists tension, compression, and racking forces. The deck's scantling is usually the same as the topsides, or might be heavier if the deck is expected to carry heavier loads ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
picture info	Jackstay A jackstay is a cable or bar between two points to support and guide a load between those points, or as an anchor to attach something to be constrained along that line. The term is mostly used in a marine context and originated on sailing ships. Note the use of "stay" implies load bearing working rigging. In diving it is also a line to guide the movements of a diver between the endpoints. Nautical applications Jackstays are used in several maritime applications. These include: * Support and guidance for transfer of personnel and materials between vessels at sea (Replenishment at sea), suspended from a traveller block and controlled by lines running in both directions. * Support and guidance for rescue or transport by breeches buoy, * A rope or rod secured along a vessel's spar to attach an edge of a sail or the end of a gaff, * A rope or rod running vertically on the forward side of the mast on which the yard moves. * A stay for racing or cruising vessels used to steady the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]