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GYN
A gyn is an improvised three legged lifting device used on sailing ships. It provides more stability than a derrick or sheers, and requires no rigging for support. Without additional support, however, it can only be used for lifting things directly up and down. Gyns may also be used to support either end of a ropeway. Two legs, called cheeks, are bound together as in the sheerlegs, with the third spar, called the prypole and is fixed under the cheek lashing to form the apex of the tripod. Alternately, a tripod lashing may be used to form the tripod, with the heel of the center spar pointing in the opposite direction of the cheeks to ensure a solid apex when raised. Only four tackles are required; three as 'splay tackles' to prevent the legs of the tripod from spreading, with the fourth tackle as lifting purchase. A timber hitch, six figure-of-eight turns, and a finishing clove hitch lash the cheeks into a crutch but not too tight because the cheeks need some room to sprea ...
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Block And Tackle
A block and tackle or only tackle is a system of two or more pulleys with a rope or cable threaded between them, usually used to lift heavy loads. The pulleys are assembled to form blocks and then blocks are paired so that one is fixed and one moves with the load. The rope is threaded through the pulleys to provide mechanical advantage that amplifies the force applied to the rope. Hero of Alexandria described cranes formed from assemblies of pulleys in the first century. Illustrated versions of Hero's ''Mechanica'' (a book on raising heavy weights) show early block and tackle systems. Overview A block is a set of pulleys or sheaves mounted on a single frame. An assembly of blocks with a rope threaded through the pulleys is called tackle. The process of threading ropes or cables through blocks is called "reeving", and a threaded block and tackle is said to have been "rove". A block and tackle system amplifies the tension force in the rope to lift heavy loads. They are comm ...
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Derrick
A derrick is a lifting device composed at minimum of one guyed mast, as in a gin pole, which may be articulated over a load by adjusting its guys. Most derricks have at least two components, either a guyed mast or self-supporting tower, and a boom hinged at its base to provide articulation, as in a ''stiffleg'' derrick. The most basic type of derrick is controlled by three or four lines connected to the top of the mast, which allow it both to move laterally and cant up and down. To lift a load, a separate line runs up and over the mast with a hook on its free end, as with a crane. Forms of derricks are commonly found aboard ships and at docking facilities. Some large derricks are mounted on dedicated vessels, and known as floating derricks and sheerlegs. The term derrick is also applied to the framework supporting a drilling apparatus in an oil rig. The derrick derives its name from a type of gallows named after Thomas Derrick, an Elizabethan era English executioner. ...
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Ropeway (sailing)
Ropeway may refer to: Cable transport * Cableway, or cable transport, a broad class of transport modes that have cables * Aerial lift, a means of cable transport in which cabins, cars, gondolas, or open chairs are hauled above the ground by means of one or more cables * Aerial tramway, a type of aerial lift which cabins shuttle back and forth on cables * Ropeway conveyor A material ropeway, ropeway conveyor (or aerial tramway in the US) is a subtype of gondola lift, from which containers for goods rather than passenger cars are suspended. Description Material ropeways are typically found around large mining conc ..., a subtype of aerial lift, from which containers for goods rather than passenger cars are suspended Other use * Ropeway (sailing), a form of naval lifting device used to transport light stores and equipment across rivers or ravines; see Gyn {{disambiguation ...
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Sailing Ship
A sailing ship is a sea-going vessel that uses sails mounted on masts to harness the power of wind and propel the vessel. There is a variety of sail plans that propel sailing ships, employing square-rigged or fore-and-aft sails. Some ships carry square sails on each mast—the brig and full-rigged ship, said to be "ship-rigged" when there are three or more masts. Others carry only fore-and-aft sails on each mast, for instance some schooners. Still others employ a combination of square and fore-and-aft sails, including the barque, barquentine, and brigantine. Early sailing ships were used for river and coastal waters in Ancient Egypt and the Mediterranean. The Austronesian peoples developed maritime technologies that included the fore-and-aft crab-claw sail and with catamaran and outrigger hull configurations, which enabled the Austronesian expansion into the islands of the Indo-Pacific. This expansion originated in Taiwan BC and propagated through Island Southea ...
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Sheers
Shear legs, also known as sheers, shears, or sheer legs, are a form of two-legged lifting device. Shear legs may be permanent, formed of a solid A-frame and supports, as commonly seen on land and the floating sheerleg, or temporary, as aboard a vessel lacking a fixed crane or derrick. When fixed, they are often used for very heavy lifting, as in tank recovery, shipbuilding, and offshore salvage operations. At dockyards they hoist masts and other substantial rigging parts on board. They are sometimes temporarily rigged on sailboats for similar tasks. Uses On land Shear legs are a lifting device related to the gin pole, derrick and tripod (lifting device). Shears are an A-frame of any kind of material such as timbers or metal, the feet resting on or in the ground or on a solid surface which will not let them move and the top held in place with guy-wires or guy ropes simply called "guys". Shear legs only need two guys whereas a gin pole needs at least three. The U. S. Army Fi ...
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Standing Rigging
Standing rigging comprises the fixed lines, wires, or rods, which support each mast or bowsprit on a sailing vessel and reinforce those spars against wind loads transferred from the sails. This term is used in contrast to running rigging, which represents the moveable elements of rigging which adjust the position and shape of the sails. Historical development Early sailing vessels used rope of hemp or other fibers, which gave way to wire ropes of various types. Galvanized steel was common for the first half of the 20th century, continuing as an inexpensive option to its 1960s successor material—stainless steel cables and rods. In the late 20th Century, racing yachts adopted composite fiber lines for standing rigging, with the goal of reducing weight and windage aloft. Materials On modern yachts, standing rigging is often stainless steel wire, Nitronic-50 stainless steel rod or synthetic fiber. Semi-rigid stainless steel wire is by far the most common as it combines extre ...
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Lashing (ropework)
A lashing is an arrangement of rope, wire, or webbing with linking device used to secure and fasten two or more items together in a somewhat rigid manner. Lashings are most commonly applied to timber poles, and are commonly associated with cargo, containerisation, the Scouting movement, and sailors. It has been imagined that the first lashing made by humans was wrapping a few strips of bark around a stone to hold it to a tree branch to make an ax to hunt and build with. In modern times, the same methods are used, but strips of bark and vines have been replaced with natural and synthetic fiber ropes. Scouts and campers use lashings to build camp gadgets and improve their campsites for comfort and convenience, including the building of rafts for transport and competitive events. Lashings are also used in pioneering, the art of creating structures such as bridges and towers, using ropes and wooden spars. There are still areas in the world where lashing spars (or poles) is the ba ...
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Timber Hitch
Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, window frames). Lumber has many uses beyond home building. Lumber is sometimes referred to as timber as an archaic term and still in England, while in most parts of the world (especially the United States and Canada) the term timber refers specifically to unprocessed wood fiber, such as cut logs or standing trees that have yet to be cut. Lumber may be supplied either rough- sawn, or surfaced on one or more of its faces. Beside pulpwood, ''rough lumber'' is the raw material for furniture-making, and manufacture of other items requiring cutting and shaping. It is available in many species, including hardwoods and softwoods, such as white pine and red pine, because of their low cost. ''Finished lumber'' is supplied in standard sizes, mostl ...
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British Army
The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gurkhas, and 28,330 volunteer reserve personnel. The modern British Army traces back to 1707, with antecedents in the English Army and Scots Army that were created during the Restoration in 1660. The term ''British Army'' was adopted in 1707 after the Acts of Union between England and Scotland. Members of the British Army swear allegiance to the monarch as their commander-in-chief, but the Bill of Rights of 1689 and Claim of Right Act 1689 require parliamentary consent for the Crown to maintain a peacetime standing army. Therefore, Parliament approves the army by passing an Armed Forces Act at least once every five years. The army is administered by the Ministry of Defence and commanded by the Chief of the General Staff. The Brit ...
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John Bell (artillerist)
John Bell (1 March 1747 – 1 June 1798) was an English artillerist. He was the eldest son of a hatter at Carlisle, Cumbria, where he was born. His father ruined himself in attempts to discover the longitude. In 1765 Bell joined the artillery. He served at Gibraltar and afterwards in England. He was at Southsea in 1782, and was an eye-witness of the foundering of the '' Royal George''. He invented a plan for destroying the wreck, which was the same as one carried out by Colonel Pasley in 1839. He also invented the 'sun proof' for testing the soundness of guns, long in use in the Royal Arsenal. The proof stages were 1. Instrumental proof; 2. Fire proof; 3. Searcher; 4. Water proof followed by 5. Sun proof: This followed the water proof and used the sun (or a special candle) and a mirror to detect any holes or sponginess. The flaws being wet were more easily detectable. He invented a ' gyn' called by his name. Bell's gyn was lighter weight and less powerful than the Gibraltar gyn. ...
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Gin Pole
A gin pole is a supported pole that uses a pulley or block and tackle on its upper end to lift loads. The lower end is braced or set in a shallow hole and positioned so the upper end lies above the object to be lifted. The pole (also known as a ''mast'', ''boom'', or ''spar'') is secured with three or more guy-wires. These are manipulated to move the load laterally, with up and down controlled by the pulley or block. In tower construction, a gin pole can also be “jumped” up the completed sections of a tower to lift the higher sections into place. The gin pole is derived from a gyn, and considered a form of derrick, called a standing derrick or pole derrick, distinguished from sheers Shear legs, also known as sheers, shears, or sheer legs, are a form of two-legged lifting device. Shear legs may be permanent, formed of a solid A-frame and supports, as commonly seen on land and the floating sheerleg, or temporary, as aboard a ... (or ''shear legs'') by having a single ...
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Sailing Rigs And Rigging
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 sailin ...
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