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Sluice
A sluice ( ) is a water channel containing a sluice gate, a type of lock to manage the water flow and water level. There are various types of sluice gates, including flap sluice gates and fan gates. Different depths are calculated when design sluice gates. Sluices are used for channeling water toward a water mill, including for transporting logs from steep hillsides. Different terms are used regionally for sluices; the terms ''sluice'', ''sluice gate'', ''knife gate'', and ''slide gate'' are used interchangeably in the water and wastewater control industry. Etymology The term "sluice" originates from the Middle English word scluse, which derived from the Old French escluse (modern French: écluse). This, in turn, came from the Late Latin exclusa, a shortening of aqua exclusa, meaning "excluded water" or "a shut-off water channel." The Latin exclusa is the feminine past participle of excludere ("to shut out, exclude"), from *ex-* ("out") and claudere ("to close"). Regional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somerset Levels
The Somerset Levels are a coastal plain and wetland area of Somerset, England, running south from the Mendips to the Blackdown Hills. The Somerset Levels have an area of about and are bisected by the Polden Hills; the areas to the south are drained by the River Parrett, and the areas to the north by the rivers Axe and Brue. The Mendip Hills separate the Somerset Levels from the North Somerset Levels. The Somerset Levels consist of marine clay "levels" along the coast and inland peat-based "moors"; agriculturally, about 70 per cent is used as grassland and the rest is arable. Willow and teazel are grown commercially and peat is extracted. A Palaeolithic flint tool found in West Sedgemoor is the earliest indication of human presence in the area. The Neolithic people exploited the reed swamps for their natural resources and started to construct wooden trackways, including the world's oldest known timber trackway, the Post Track, dating from about 3800 BC. The Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Mill
A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of many material goods, including flour, lumber, paper, textiles, and many metal products. These watermills may comprise gristmills, sawmills, paper mills, textile mills, hammermills, trip hammering mills, rolling mills, and wire drawing mills. One major way to classify watermills is by wheel orientation (vertical or horizontal), one powered by a vertical waterwheel through a gear mechanism, and the other equipped with a horizontal waterwheel without such a mechanism. The former type can be further subdivided, depending on where the water hits the wheel paddles, into undershot, overshot, breastshot and pitchback (backshot or reverse shot) waterwheel mills. Another way to classify water mills is by an essential trait about their loca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lock (water Navigation)
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 chamber in a permanently fixed position in which the water level can be varied. (In a caisson lock, a boat lift, or on a canal inclined plane, it is the chamber itself (usually then called a caisson (engineering), 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. Over time, more and larger locks have been used in canals to allow a more direct route to be taken. History Ancient Egypt In Ancient Egypt, the river-locks was probably part of the Canal of the Pharaohs: Ptolemy II is credited by some for being the first to solve the problem of keeping the Nile free of salt water when his engineers invented the lock around 274/273 BC. Ancient China During 960–1279 CE, the natural extension o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mill Race
A mill race, millrace or millrun, mill lade (Scotland) or mill leat (Southwest England) is the current of water that turns a water wheel, or the channel ( sluice) conducting water to or from a water wheel. Compared with the broad waters of a mill pond, the narrow current is swift and powerful. The race leading to the water wheel on a wide stream or mill pond is called the head race (or headraceDictionary.com, word definition), and the race leading away from the wheel is called the tail raceChamber's Twentieth Century Dictionary, 1968, p=674 (or tailrace). A mill race has many geographically specific names, such as '' leat, lade, flume, goit, penstock''. These words all have more precise definitions and meanings will differ elsewhere. The original undershot waterwheel, described by Vitruvius, was a 'run of the river wheel' placed so a fast flowing stream would press against and turn the bottom of a bucketed wheel. In the first meaning of the term, the millrace was the stream; i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penstock
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. The term is of Scots origin, and was inherited from the earlier technology of mill ponds and watermills, with penstocks diverting pond waters to drive the mills. Hydroelectric systems and dams Penstocks for hydroelectric installations are normally equipped with a gate system and a surge tank. They can be a combination of many components such as anchor block, drain valve, air bleed valve, and support piers depending on the application. Flow is regulated to suit turbine operation and is cut off when turbines are not in service. Penstocks, particularly where used in polluted water systems, need to be maintained by hot water washing, manual cleaning, antifouling coatings, allowing waters to go anoxic, and desiccation used to dry fouling out so that it may slough off or become easier to remove through manual processes. The t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weir
A weir or low-head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the water level. Weirs are also used to control the flow of water for outlets of lakes, ponds, and reservoirs. There are many weir designs, but commonly water flows freely over the top of the weir crest before cascading down to a lower level. There is no single definition as to what constitutes a weir. ''Weir'' can also refer to the skimmer found in most in-ground swimming pools, which controls the flow of water pulled into the filtering system. Etymology The word likely originated from Middle English ''were'', Old English ''wer'', a derivative of the root of the verb ''werian,'' meaning "to defend, dam". The German cognate is ''Wehr'', which means the same as English weir. Function Commonly, weirs are used to prevent flooding, measure water discharge, and help render rivers more Navigability, navigable by boat. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leat
A leat (; also lete or leet, or millstream) is the name, common in the south and west of England and in Wales, for an artificial watercourse or aqueduct dug into the ground, especially one supplying water to a watermill or its mill pond. Other common uses for leats include delivery of water for hydraulic mining and mineral concentration, for irrigation, to serve a dye works or other industrial plant, and provision of drinking water to a farm or household or as a catchment cut-off to improve the yield of a reservoir. According to the ''Oxford English Dictionary'', ''leat'' is cognate with ''let'' in the sense of "allow to pass through". Other names for the same thing include ''fleam'' (probably a leat supplying water to a mill that did not have a millpool). In parts of northern England, for example around Sheffield, the equivalent word is ''goit''. In southern England, a leat used to supply water for water-meadow irrigation is often called a ''carrier'', ''top carrier'', or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Needle Dam
A needle dam is a weir designed to maintain the level or flow of a river through the use of thin "needles" of wood. The needles are leaned against a solid frame and are not intended to be water-tight. Individual needles can be added or removed by hand to constrict the flow of the river, forming a sluice. One early needle dam maintains the level of Lake Lucerne in Lucerne, Switzerland by restricting the flow of the Reuss, several are still in operation on the Meuse, France and others were built in the United States in the 19th century. The first needle dam in the United States was completed in 1896 on the Big Sandy River, downstream from the city of Louisa, Kentucky. A similar approach, now known as paddle and rymer weirs, was used since medieval times on the River Thames in England to create flash lock A flash lock is a type of lock (water transport), lock for river or canal transport. Early locks were designed with a single gate, known as a flash lock or staunch loc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hollandic Water Line
The Dutch Waterline (; modern spelling: ''Hollandse Waterlinie'') was a series of water-based defences conceived by Maurice of Nassau in the early 17th century, and realised by his half brother Frederick Henry. Combined with natural bodies of water, the Waterline could be used to transform Holland, the westernmost region of the Netherlands and adjacent to the North Sea, almost into an island. In the 19th century, the Line was extended to include Utrecht. On July 26, 2021, the line was added to the Defence Line of Amsterdam to become the Dutch Water Defence Lines UNESCO World Heritage Site. History Early in the Eighty Years' War of Independence against Spain, the Dutch realized that flooding low-lying areas formed an excellent defence against enemy troops. This was demonstrated, for example, during the Siege of Leiden in 1574. In the latter half of the war, when the province of Holland had been freed of Spanish troops, Maurice of Nassau planned to defend it with a line of floo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ss Sluice2
The ''Schutzstaffel'' (; ; SS; also stylised with SS runes as ''ᛋᛋ'') was a major paramilitary organisation under Adolf Hitler and the Nazi Party in Nazi Germany, and later throughout German-occupied Europe during World War II. It began with a small guard unit known as the ''Saal-Schutz'' ("Hall Security") made up of party volunteers to provide security for party meetings in Munich. In 1925, Heinrich Himmler joined the unit, which had by then been reformed and given its final name. Under his direction (1929–1945) it grew from a small paramilitary formation during the Weimar Republic to one of the most powerful organisations in Nazi Germany. From the time of the Nazi Party's rise to power until the regime's collapse in 1945, the SS was the foremost agency of security, mass surveillance, and state terrorism within Germany and German-occupied Europe. The two main constituent groups were the '' Allgemeine SS'' (General SS) and ''Waffen-SS'' (Armed SS). The ''Allgemeine SS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
