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Windlass
The windlass is an apparatus for moving heavy weights. Typically, a windlass consists of a horizontal cylinder (barrel), which is rotated by the turn of a crank or belt. A winch is affixed to one or both ends, and a cable or rope is wound around the winch, pulling a weight attached to the opposite end. The Greek scientist Archimedes was the inventor of the windlass. The oldest depiction of a windlass for raising water can be found in the Book of Agriculture published in 1313 by the Chinese official Wang Zhen of the Yuan Dynasty ( 1290–1333). Uses *Vitruvius, a military engineer writing about 28 BC, defined a machine as "a combination of timber fastened together, chiefly efficacious in moving great weights." About a century later, Hero of Alexandria summarized the practice of his day by naming the "five simple machines" for "moving a given weight by a given force" as the lever, windlass, screw for power, wedge, and tackle block (pulley). Until nearly the end of the nine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchor Windlass
A windlass is a machine used on ships that is used to let-out and heave-up equipment such as a ship's anchor or a fishing trawl. On some ships, it may be located in a specific room called the windlass room. An anchor windlass is a machine that restrains and manipulates the anchor chain on a boat, allowing the anchor to be raised and lowered by means of chain cable. A notched wheel engages the links of the chain or the rope. A trawl windlass is a similar machine that restrains or manipulates the trawl on a commercial fishing vessel. The trawl is a sort of big fishing net that is wound on the windlass. The fishermen either let-out the trawl or heave-up the trawl during fishing operations. A brake is provided for additional control. The windlass is usually powered by an electric or hydraulic motor operating via a gear train. Horizontal or vertical Technically speaking, the term "windlass" refers only to horizontal winches. Vertical designs are correctly called capstans. Horizon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential Pulley
A differential pulley —also called "Weston differential pulley", sometimes "differential hoist", "chain hoist", or colloquially "chain fall"— is used to manually lift very heavy objects like Internal combustion engine, car engines. It is operated by pulling upon the slack section of a continuous chain that wraps around two pulleys on a common shaft. (The two pulleys are joined together such that they rotate as a unit on the single shaft that they share.) The relative sizing of the two connected pulleys determines the maximum weight that can be lifted by hand. If the pulley radii are close enough, then the load will remain in place (and not lower under the force of gravity) until the chain is pulled. History The differential pulley was invented in 1854 by Thomas Aldridge Weston from King's Norton, England. The pulleys were manufactured in collaboration with Richard and George Tangye. According to Richard Tangye's autobiography, the Weston differential pulley evolved from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crossbow
A crossbow is a ranged weapon using an elastic launching device consisting of a bow-like assembly called a ''prod'', mounted horizontally on a main frame called a ''tiller'', which is hand-held in a similar fashion to the stock of a long firearm. Crossbows shoot arrow-like projectiles called '' bolts'' or ''quarrels''. A person who shoots crossbow is called a ''crossbowman'' or an '' arbalist'' (after the arbalest, a European crossbow variant used during the 12th century). Although crossbows and bows use the same launch principle, the difference is that an archer must maintain a bow's draw manually by pitching the bowstring with fingers, pulling it back with arm and back muscles and then holding that same form in order to aim (which distresses the body and demands significant physical strength and stamina); while a crossbow utilizes a locking mechanism to maintain the draw, limiting the shooter's exertion to only pulling the string into lock and then releasing the shot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capstan (nautical)
A capstan is a vertical- axled rotating machine developed for use on sailing ships to multiply the pulling force of seamen when hauling ropes, cables, and hawsers. The principle is similar to that of the windlass, which has a horizontal axle. History The word, connected with the Old French ''capestan'' or ''cabestan(t)'', from Old Provençal ''cabestan'', from ''capestre'' "pulley cord," from Latin ''capistrum'', -a halter, from ''capere'', to take hold of, seems to have come into English (14th century) from Portuguese or Spanish shipmen at the time of the Crusades. Both device and word are considered Spanish inventions. Early form In its earliest form, the capstan consisted of a timber mounted vertically through a vessel's structure which was free to rotate. Levers, known as bars, were inserted through holes at the top of the timber and used to turn the capstan. A rope wrapped several turns around the drum was thus hauled upon. A rudimentary ratchet was provided to hold t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lock (water Transport)
A lock is a device used for raising and lowering boats, ships and other watercraft between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the chamber itself (usually then called a caisson) that rises and falls. Locks are used to make a river more easily navigable, or to allow a canal to cross land that is not level. Later canals used more and larger locks to allow a more direct route to be taken. Pound lock A ''pound lock'' is most commonly used on canals and rivers today. A pound lock has a chamber with gates at both ends that control the level of water in the pound. In contrast, an earlier design with a single gate was known as a flash lock. Pound locks were first used in China during the Song Dynasty (960–1279 AD), having been pioneered by the Song politician and naval en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchor
An anchor is a device, normally made of metal , used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ''ancora'', which itself comes from the Greek ἄγκυρα (ankȳra). Anchors can either be temporary or permanent. Permanent anchors are used in the creation of a mooring, and are rarely moved; a specialist service is normally needed to move or maintain them. Vessels carry one or more temporary anchors, which may be of different designs and weights. A sea anchor is a drag device, not in contact with the seabed, used to minimise drift of a vessel relative to the water. A drogue is a drag device used to slow or help steer a vessel running before a storm in a following or overtaking sea, or when crossing a bar in a breaking sea.. Overview Anchors achieve holding power either by "hooking" into the seabed, or mass, or a combination of the two. Permanent moorings use large masses (common ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winch
A winch is a mechanical device that is used to pull in (wind up) or let out (wind out) or otherwise adjust the tension of a rope or wire rope (also called "cable" or "wire cable"). In its simplest form, it consists of a spool (or drum) attached to a hand crank. Traditionally, winches on ships accumulated wire or rope on the drum; those that do not accumulate, and instead pass on the wire/rope (see yacht photo above), are called capstans. Despite this, sailboat capstans are most often referred to as winches. Winches are the basis of such machines as tow trucks, steam shovels and elevators. More complex designs have gear assemblies and can be powered by electric, hydraulic, pneumatic or internal combustion drives. It might include a solenoid brake and/or a Mechanical brake stretch wrapper, mechanical brake or ratchet (device), ratchet and pawl which prevents it unwinding unless the pawl is retracted. The rope may be stored on the winch. When trimming a line on a sailboat, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archimedes
Archimedes of Syracuse (;; ) was a Greek mathematician, physicist, engineer, astronomer, and inventor from the ancient city of Syracuse in Sicily. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Considered the greatest mathematician of ancient history, and one of the greatest of all time,* * * * * * * * * * Archimedes anticipated modern calculus and analysis by applying the concept of the infinitely small and the method of exhaustion to derive and rigorously prove a range of geometrical theorems. These include the area of a circle, the surface area and volume of a sphere, the area of an ellipse, the area under a parabola, the volume of a segment of a paraboloid of revolution, the volume of a segment of a hyperboloid of revolution, and the area of a spiral. Heath, Thomas L. 1897. ''Works of Archimedes''. Archimedes' other mathematical achievements include deriving an approximation of pi, defining and in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tourniquet
A tourniquet is a device that is used to apply pressure to a limb or extremity in order to stop the flow of blood. It may be used in emergencies, in surgery, or in post-operative rehabilitation. A simple tourniquet can be made from a stick and a rope, but the use of makeshift tourniquets has been reduced over time due to their ineffectiveness compared to a commercial and professional tourniquet. This may stem the flow of blood, but side effects such as soft tissue damage and nerve damage may occur. Types There are three types of tourniquets: surgical tourniquets, emergency tourniquets, and rehabilitation tourniquets. Surgical tourniquets Silicone ring tourniquets, or elastic ring tourniquets, are self-contained mechanical devices that do not require any electricity, wires or tubes. The tourniquet comes in a variety of sizes. To determine the correct product size, the patient's limb circumference at the desired occlusion location should be measured, as well as their bloo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Machine
A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. Usually the term refers to the six classical simple machines that were defined by Renaissance scientists: * Lever * Wheel and axle * Pulley * Inclined plane * Wedge * Screw A simple machine uses a single applied force to do work against a single load force. Ignoring friction losses, the work done on the load is equal to the work done by the applied force. The machine can increase the amount of the output force, at the cost of a proportional decrease in the distance moved by the load. The ratio of the output to the applied force is called the ''mechanical advantage''. Simple machines can be regarded as the elementary "building blocks" of which all more complicated machines (sometimes called "compound machines") are composed. For example, wheels, levers, and pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whim (mining)
A whim, also called a whim gin or a horse capstan, is a device similar to a windlass which is used in mining for hauling materials to the surface. It comprises a capstan or a wide drum with a vertical axle. A rope is wound around the drum, with both ends traversing several pulleys and hanging down the mine shaft. As the drum is turned around, one end of the rope is lowered, carrying an empty bucket, while the other one is raised, carrying a full load. The major benefit of a whim is that its operation can be performed at a distance from the shaft, thus resolving some of the congestion. Early whims were horse-powered, but later they were powered by waterwheels or steam engines, including the most advanced Cornish engines. Whims were used in coal mines until the end of the nineteenth century. Horse whims were also used to power team boats. The gin wheel at Nottingham Industrial Museum dating from 1844, is a wooden drum, set on a vertical pole within a wooden frame, with a horizont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turnbridge Liftbridge RLH
Turnbridge is the area to the east of Huddersfield town centre ring road in West Yorkshire, England. It forms a corridor along which passes St Andrews Road, (B6432), and the Huddersfield Broad Canal to Aspley, where the Broad Canal meets Huddersfield Narrow Canal in the Aspley Basin. There are places for a limited number of narrowboat moorings. Some have electric and fresh water services. The area is reputed to have gained its name from a turning bridge across the canal. In 1865 this was replaced by Turnbridge Lift Bridge. File:Huddersfield Broad Canal RLH.jpg, Turnbridge Section of Huddersfield Broad Canal File:Turnbridge Liftbridge RLH.jpg, Turnbridge Lift Bridge over the Huddersfield Broad Canal The Huddersfield Broad Canal or Sir John Ramsden's Canal, is a wide-locked navigable canal in West Yorkshire in northern England. The waterway is 3.75 miles (6 km) long and has 9 wide locks. It follows the valley of the River Colne and c ... Areas of Huddersfield [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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