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61-496: The Jubilee River is a hydraulic channel in southern England. It is 11.6 km (7.2 mi) long and is on average 45 metres (148 feet) wide. It was constructed in the late 1990s and early 2000s to take overflow from the River Thames and so alleviate flooding to areas in and around the towns of Maidenhead , Windsor , and Eton in the counties of Berkshire and Buckinghamshire . It achieves this by taking water from

122-496: A waterwheel to power the bellows of a blast furnace producing cast iron . Zhang Heng was the first to employ hydraulics to provide motive power in rotating an armillary sphere for astronomical observation . In ancient Sri Lanka, hydraulics were widely used in the ancient kingdoms of Anuradhapura and Polonnaruwa . The discovery of the principle of the valve tower, or valve pit, (Bisokotuwa in Sinhalese) for regulating

183-443: A baffle of concrete blocks but usually have a "flip lip" and/or dissipator basin, which creates a hydraulic jump , protecting the toe of the dam from erosion. Stepped channels and spillways have been used for over 3,000 years. Despite being superseded by more modern engineering techniques such as hydraulic jumps in the mid twentieth century, since around 1985 interest in stepped spillways and chutes has been renewed, partly due to

244-419: A channel which would be 50 metres (160 ft) wide and 12 kilometres (7.5 mi) long. In October 1992, a planning enquiry was held to consider the proposals. During that enquiry, P. Ackers, one of the assessors, expressed grave doubts about the hydraulic modelling that had been used to justify the scheme, suggesting that it was too optimistic. The scheme did not receive government approval until 1995; around

305-501: A finite rate of pressure rise requires that any net flow into the collected fluid volume create a volumetric change. Stilling basin Spillways can include floodgates and fuse plugs to regulate water flow and reservoir level. Such features enable a spillway to regulate downstream flow—by releasing water in a controlled manner before the reservoir is full, operators can prevent an unacceptably large release later. Other uses of

366-402: A large scale to prospect for and then extract metal ores . They used lead widely in plumbing systems for domestic and public supply, such as feeding thermae . Hydraulic mining was used in the gold-fields of northern Spain, which was conquered by Augustus in 25 BC. The alluvial gold-mine of Las Medulas was one of the largest of their mines. At least seven long aqueducts worked it, and

427-565: A plunge pool, or two ski jumps can direct their water discharges to collide with one another. Third, a stilling basin at the terminus of a spillway serves to further dissipate energy and prevent erosion. They are usually filled with a relatively shallow depth of water and sometimes lined with concrete. A number of velocity-reducing components can be incorporated into their design to include chute blocks, baffle blocks, wing walls, surface boils, or end sills. Spillway gates may operate suddenly without warning, under remote control. Trespassers within

488-516: A public enquiry. For example, at Manor Farm a weir was constructed. Conception to fruition took about 20 years. Water is admitted to the river through sluice gates at the upstream end of the channel near Taplow. This is normally controlled by measurements of the water levels below Boulters Lock and the estimated flow of the Thames at the Datchet gauging station near Windsor. The first serious test of

549-517: A reciprocating device with hinged valves. The earliest programmable machines were water-powered devices developed in the Muslim world. A music sequencer , a programmable musical instrument , was the earliest type of programmable machine. The first music sequencer was an automated water-powered flute player invented by the Banu Musa brothers, described in their Book of Ingenious Devices , in

610-459: A routine basis for purposes such as water supply and hydroelectricity generation. A spillway is located at the top of the reservoir pool. Dams may also have bottom outlets with valves or gates which may be operated to release flood flow, and a few dams lack overflow spillways and rely entirely on bottom outlets. The two main types of spillways are controlled and uncontrolled. A controlled spillway has mechanical structures or gates to regulate

671-592: A watering channel for Samos , the Tunnel of Eupalinos . An early example of the usage of hydraulic wheel, probably the earliest in Europe, is the Perachora wheel (3rd century BC). In Greco-Roman Egypt , the construction of the first hydraulic machine automata by Ctesibius (flourished c. 270 BC) and Hero of Alexandria (c. 10 – 80 AD) is notable. Hero describes several working machines using hydraulic power, such as

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732-434: Is a technology and applied science using engineering , chemistry , and other sciences involving the mechanical properties and use of liquids . At a very basic level, hydraulics is the liquid counterpart of pneumatics , which concerns gases . Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on applied engineering using the properties of fluids. In its fluid power applications, hydraulics

793-460: Is designed like an inverted bell , where water can enter around the entire perimeter. These uncontrolled spillways are also called morning glory (after the flower ), or glory hole spillways. In areas where the surface of the reservoir may freeze, this type of spillway is normally fitted with ice-breaking arrangements to prevent the spillway from becoming ice-bound. Some bell-mouth spillways are gate-controlled. The highest morning glory spillway in

854-443: Is set by dam safety guidelines, based on the size of the structure and the potential loss of human life or property downstream. The United States Army Corps of Engineers bases their requirements on the probable maximum flood (PMF) and the probable maximum precipitation (PMP). The PMP is the largest precipitation thought to be physically possible in the upstream watershed. Dams of lower hazard may be allowed to have an IDF less than

915-458: Is the branch of hydraulics dealing with free surface flow, such as occurring in rivers , canals , lakes , estuaries , and seas . Its sub-field open-channel flow studies the flow in open channels . Early uses of water power date back to Mesopotamia and ancient Egypt , where irrigation has been used since the 6th millennium BC and water clocks had been used since the early 2nd millennium BC. Other early examples of water power include

976-399: Is transmitted undiminished throughout the fluids. A French physician, Poiseuille (1797–1869) researched the flow of blood through the body and discovered an important law governing the rate of flow with the diameter of the tube in which flow occurred. Several cities developed citywide hydraulic power networks in the 19th century, to operate machinery such as lifts, cranes, capstans and

1037-436: Is used for the generation, control, and transmission of power by the use of pressurized liquids. Hydraulic topics range through some parts of science and most of engineering modules, and they cover concepts such as pipe flow , dam design, fluidics , and fluid control circuitry. The principles of hydraulics are in use naturally in the human body within the vascular system and erectile tissue . Free surface hydraulics

1098-483: Is well used by walkers, runners, swimmers, canoeists, wildlife enthusiasts and cyclists: a footpath combined with National Cycle Route 61 runs along virtually its entire length. A wide variety of bird life can be seen along the river, including green woodpeckers, cormorants, lapwing and red kites. During flooding in the early months of 2014, some residents of Ham Island (in Old Windsor ) and Wraysbury said that

1159-933: The Qanat system in ancient Persia and the Turpan water system in ancient Central Asia. In the Persian Empire or previous entities in Persia, the Persians constructed an intricate system of water mills, canals and dams known as the Shushtar Historical Hydraulic System . The project, commenced by Achaemenid king Darius the Great and finished by a group of Roman engineers captured by Sassanian king Shapur I , has been referred to by UNESCO as "a masterpiece of creative genius". They were also

1220-484: The ancient Near East in the 4th century BC, specifically in the Persian Empire before 350 BCE, in the regions of Iraq , Iran , and Egypt . In ancient China there was Sunshu Ao (6th century BC), Ximen Bao (5th century BC), Du Shi (circa 31 AD), Zhang Heng (78 – 139 AD), and Ma Jun (200 – 265 AD), while medieval China had Su Song (1020 – 1101 AD) and Shen Kuo (1031–1095). Du Shi employed

1281-460: The force pump , which is known from many Roman sites as having been used for raising water and in fire engines. In the Roman Empire , different hydraulic applications were developed, including public water supplies, innumerable aqueducts , power using watermills and hydraulic mining . They were among the first to make use of the siphon to carry water across valleys, and used hushing on

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1342-401: The 9th century. In 1206, Al-Jazari invented water-powered programmable automata/ robots . He described four automaton musicians, including drummers operated by a programmable drum machine , where they could be made to play different rhythms and different drum patterns. In 1619 Benedetto Castelli , a student of Galileo Galilei , published the book Della Misura dell'Acque Correnti or "On

1403-789: The Bath Road Bridge. The channel also had to be taken through Black Potts Viaduct , a series of 13 brick arches carrying the Waterloo to Windsor railway line over the Thames flood plain. Protective concrete and blue brick barriers were built around the older brickwork to preserve the viaduct's structural integrity, as well as to control gates to adjust the amount of water rejoining the Thames immediately downstream. The 11.6 km (7.2 mi) channel involved complex civil engineering to deal with utility conduits, roads and railways, as well as ecological and social issues, entailing compulsory purchases, community lectures and consultations and

1464-591: The Islamic world, including fulling mills, gristmills , paper mills , hullers , sawmills , ship mills , stamp mills , steel mills , sugar mills , and tide mills . By the 11th century, every province throughout the Islamic world had these industrial mills in operation, from Al-Andalus and North Africa to the Middle East and Central Asia . Muslim engineers also used water turbines , employed gears in watermills and water-raising machines, and pioneered

1525-709: The Jubilee River had increased the height of the flooded Thames in those villages which, along with much of the river upstream of London , saw water levels unprecedented since 1947. Wraysbury had also suffered significant flooding in 2003. The Environment Agency in the 2010s is undertaking a widening and dredging programme of Thames works to assist with downstream flows. 51°30′17″N 0°39′10″W  /  51.5047°N 0.6527°W  / 51.5047; -0.6527 Hydraulic Hydraulics (from Ancient Greek ὕδωρ ( húdōr )  ' water ' and αὐλός ( aulós )  ' pipe ')

1586-677: The Measurement of Running Waters," one of the foundations of modern hydrodynamics. He served as a chief consultant to the Pope on hydraulic projects, i.e., management of rivers in the Papal States, beginning in 1626. The science and engineering of water in Italy from 1500-1800 in books and manuscripts is presented in an illustrated catalog published in 2022. Blaise Pascal (1623–1662) studied fluid hydrodynamics and hydrostatics, centered on

1647-463: The PMF. As water passes over a spillway and down the chute, potential energy converts into increasing kinetic energy . Failure to dissipate the water's energy can lead to scouring and erosion at the dam's toe (base). This can cause spillway damage and undermine the dam's stability. To put this energy in perspective, the spillways at Tarbela Dam could, at full capacity, produce 40,000 MW; about 10 times

1708-558: The Queen's main residences was at Windsor Castle , in one of the three towns being protected by the scheme. The watercourse was designed to look like a natural river; its banks have artificially constructed wildlife habitats intended to replace those lost from the banks of the Thames during urban expansion in the 19th and 20th centuries. During construction 38 hectares (94 acres) of reed beds and 5 hectares (12 acres) of wet woodland were laid down and about 250,000 trees were planted. The river

1769-422: The actual capacity of the channel was around two-thirds of its design capacity, and factors affecting this were the banks being too low, the use of inappropriate materials, and failure to follow standard design criteria. A programme of repairs and upgrades to rectify the problems began, at a cost of £3.5 million, and took until 2006 to complete. The Environment Agency sued their lead design consultants for recovery of

1830-416: The basic principles of hydraulics, some teachers use a hydraulic analogy to help students learn other things. For example: The conservation of mass requirement combined with fluid compressibility yields a fundamental relationship between pressure, fluid flow, and volumetric expansion, as shown below: Assuming an incompressible fluid or a "very large" ratio of compressibility to contained fluid volume,

1891-407: The capacity of its power plant. The energy can be dissipated by addressing one or more parts of a spillway's design. First, on the spillway surface itself by a series of steps along the spillway (see stepped spillway ). Second, at the base of a spillway, a flip bucket can create a hydraulic jump and deflect water upwards. A ski jump can direct water horizontally and eventually down into

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1952-660: The consulting engineers. Principal works were the creation of the channel, various flow control mechanisms and bridges for road, rail and foot traffic. One of the challenges was the Dorney Bridge, built to take the channel beneath the Great Western Main Line . The 19th-century Brunel -designed railway embankment continued in use, carrying passenger and goods trains between London and destinations including South Wales , Cornwall and Bristol throughout construction. The 12 m (39 ft) high embankment

2013-437: The dam down a smooth decline into the river below. These are usually designed following an ogee curve . Most often, they are lined on the bottom and sides with concrete to protect the dam and topography. They may have a controlling device and some are thinner and multiply-lined if space and funding are tight. In addition, they are not always intended to dissipate energy like stepped spillways. Chute spillways can be ingrained with

2074-414: The difference in height between the intake and the outlet to create the pressure difference required to remove excess water. Siphons require priming to remove air in the bend for them to function, and most siphon spillways are designed to use water to automatically prime the siphon. One such design is the volute siphon, which employs volutes or fins on a funnel to form water into a vortex that draws air out of

2135-406: The difference in pressure is proportional to the difference in height, and this difference remains the same whether or not the overall pressure of the fluid is changed by applying an external force. This implies that by increasing the pressure at any point in a confined fluid, there is an equal increase at every other end in the container, i.e., any change in pressure applied at any point of the liquid

2196-483: The escape of water is credited to ingenuity more than 2,000 years ago. By the first century AD, several large-scale irrigation works had been completed. Macro- and micro-hydraulics to provide for domestic horticultural and agricultural needs, surface drainage and erosion control, ornamental and recreational water courses and retaining structures and also cooling systems were in place in Sigiriya , Sri Lanka. The coral on

2257-423: The flood is sometimes expressed as a return period . A 100-year recurrence interval is the flood magnitude expected to be exceeded on the average of once in 100 years. This parameter may be expressed as an exceedance frequency with a 1% chance of being exceeded in any given year. The volume of water expected during the design flood is obtained by hydrologic calculations of the upstream watershed. The return period

2318-722: The flood plain of the River Thames. The concept of a parallel channel which could take water from the Thames above Maidenhead and return it below Windsor was conceived in the 1980s, and became known as the Maidenhead, Windsor and Eton Flood Alleviation Scheme. When the ten regional water authorities were privatised, as a result of the Water Act 1989 , responsibility for rivers passed to the National Rivers Authority , which soon afterwards submitted plans for

2379-502: The flow at Datchet was some 320 cubic metres per second, 140 cubic metres per second above the recommended flow. A subsequent investigation revealed that the Environment Agency had known there were defects in the channel since November 2002, and this had been a major factor in not operating it correctly. When flood water was admitted to the channel, the flows were well short of its designed maximum flow capacity, and yet there

2440-605: The inventors of the Qanat , an underground aqueduct, around the 9th century BC. Several of Iran's large, ancient gardens were irrigated thanks to Qanats. The Qanat spread to neighboring areas, including the Armenian highlands . There, starting in the early 8th century BC, the Kingdom of Urartu undertook significant hydraulic works, such as the Menua canal . The earliest evidence of water wheels and watermills date back to

2501-399: The left (at this point eastern) bank of the Thames upstream of Boulter's Lock near Maidenhead and returning it via the north bank downstream of Eton. Although successful in its stated aims, residents of villages downstream, such as Wraysbury, claim it has increased flooding in those locations. Parts of the towns of Windsor, Eton and Maidenhead are prone to flooding, because they are built on

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2562-635: The like. Joseph Bramah (1748–1814) was an early innovator and William Armstrong (1810–1900) perfected the apparatus for power delivery on an industrial scale. In London, the London Hydraulic Power Company was a major supplier its pipes serving large parts of the West End of London , City and the Docks , but there were schemes restricted to single enterprises such as docks and railway goods yards . After students understand

2623-456: The massive rock at the site includes cisterns for collecting water. Large ancient reservoirs of Sri Lanka are Kalawewa (King Dhatusena), Parakrama Samudra (King Parakrama Bahu), Tisa Wewa (King Dutugamunu), Minneriya (King Mahasen) In Ancient Greece , the Greeks constructed sophisticated water and hydraulic power systems. An example is a construction by Eupalinos , under a public contract, of

2684-537: The new structure occurred during the flooding of early January 2003, and revealed a number of defects in the design. With both the Boulters Lock levels and the Datchet flow indicating that the channel was needed, the Taplow sluices were opened briefly on 1 January, but were then shut again until 4 January, by which time the Boulters Lock levels were 2 feet 4 inches (0.71 m) above the target levels, and

2745-417: The principles of hydraulic fluids. His discovery on the theory behind hydraulics led to his invention of the hydraulic press , which multiplied a smaller force acting on a smaller area into the application of a larger force totaled over a larger area, transmitted through the same pressure (or exact change of pressure) at both locations. Pascal's law or principle states that for an incompressible fluid at rest,

2806-424: The rate of flow. This design allows nearly the full height of the dam to be used for water storage year-round, and flood waters can be released as required by opening one or more gates. An uncontrolled spillway, in contrast, does not have gates; when the water rises above the lip or crest of the spillway, it begins to be released from the reservoir. The rate of discharge is controlled only by the height of water above

2867-540: The remedial costs, and were refunded £2.75 million in an out-of-court settlement, after they admitted that the design and construction were sub-standard. The name used during planning was the "Maidenhead, Windsor and Eton Flood Alleviation Scheme" (MWEFAS). The choice of a name for the river was put to the local population in a poll. The result was a strong preference for 'Jubilee', as it was being completed in Queen Elizabeth's Golden Jubilee year of 2002 and one of

2928-431: The reservoir's spillway. The fraction of storage volume in the reservoir above the spillway crest can only be used for the temporary storage of floodwater; it cannot be used as water supply storage because it sits higher than the dam can retain it. In an intermediate type, normal level regulation of the reservoir is controlled by the mechanical gates. In this case, the dam is not designed to function with water flowing over

2989-459: The river downstream. One parameter of spillway design is the largest flood it is designed to handle. The structures must safely withstand the appropriate spillway design flood (SDF), sometimes called the inflow design flood (IDF). The magnitude of the SDF may be set by dam safety guidelines, based on the size of the structure and the potential loss of human life or property downstream. The magnitude of

3050-573: The same time, there was further reorganisation of the water industry, with the Environment Agency replacing the National Rivers Authority. Although Ackers' concerns had not been addressed, it commissioned the design and construction of the scheme as originally conceived, at a cost of £110 million. Throughout the planning process, from initial feasibility studies to delivery of the project, Lewin, Fryer and Partners were

3111-414: The spillway are at high risk of drowning. Spillways are usually fenced and equipped with locked gates to prevent casual trespassing within the structure. Warning signs, sirens, and other measures may be in place to warn users of the downstream area of sudden release of water. Operating protocols may require "cracking" a gate to release a small amount of water to warn persons downstream. The sudden closure of

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3172-438: The spillway gates. Although many months may be needed for construction crews to restore the fuse plug and channel after such an operation, the total damage and cost to repair is less than if the main water-retaining structures had been overtopped. The fuse plug concept is used where building a spillway with the required capacity would be costly. A chute spillway is a common and basic design that transfers excess water from behind

3233-424: The system. The priming happens automatically when the water level rises above the inlets. The ogee crest over-tops a dam, a side channel wraps around the topography of a dam, and a labyrinth uses a zig-zag design to increase the sill length for a thinner design and increased discharge. A drop inlet resembles an intake for a hydroelectric power plant, and transfers water from behind the dam directly through tunnels to

3294-412: The term "spillway" include bypasses of dams and outlets of channels used during high water, and outlet channels carved through natural dams such as moraines . Water normally flows over a spillway only during flood periods, when the reservoir has reached its capacity and water continues entering faster than it can be released. In contrast, an intake tower is a structure used to control water release on

3355-414: The top if it, either due to the materials used for its construction or conditions directly downstream. If inflow to the reservoir exceeds the gate's capacity, an artificial channel called an auxiliary or emergency spillway will convey water. Often, that is intentionally blocked by a fuse plug . If present, the fuse plug is designed to wash out in case of a large flood, greater than the discharge capacity of

3416-435: The use of dams as a source of water power, used to provide additional power to watermills and water-raising machines. Al-Jazari (1136–1206) described designs for 50 devices, many of them water-powered, in his book, The Book of Knowledge of Ingenious Mechanical Devices , including water clocks, a device to serve wine, and five devices to lift water from rivers or pools. These include an endless belt with jugs attached and

3477-474: The use of new construction materials (e.g. roller-compacted concrete , gabions ) and design techniques (e.g. embankment overtopping protection). The steps produce considerable energy dissipation along the chute and reduce the size of the required downstream energy dissipation basin. Research is still active on the topic, with newer developments on embankment dam overflow protection systems, converging spillways and small weir design. A bell-mouth spillway

3538-528: The water streams were used to erode the soft deposits, and then wash the tailings for the valuable gold content. In the Muslim world during the Islamic Golden Age and Arab Agricultural Revolution (8th–13th centuries), engineers made wide use of hydropower as well as early uses of tidal power , and large hydraulic factory complexes. A variety of water-powered industrial mills were used in

3599-695: The world is at Hungry Horse Dam in Montana, U.S., and is controlled by a 64-by-12-foot (19.5 by 3.7 m) ring gate. The bell-mouth spillway in Covão dos Conchos reservoir in Portugal is constructed to look like a natural formation. The largest bell-mouth spillway is in Geehi Dam , in New South Wales, Australia, measuring 105 ft (32 m) in diameter at the lake's surface. A siphon uses

3660-564: Was significant erosion of the banks in several places. There was considerable erosion at the Taplow Sluice, due to the lack of a stilling basin ; embankments at Marsh Lane were badly damaged; the weir at Manor Farm was bent in the middle; the protection on the downstream face of Slough weir was swept away; and in Datchet, the Myrke embankment nearly collapsed. An independent assessment by the engineering consultancy WS Atkins identified that

3721-481: Was stabilised along 30m of its length by freezing over a period of three months, using 175 brine tubes cooled to −25 °C (−13 °F). A tunnel was excavated through the frozen ground to just 50 millimetres (2.0 in) wider than the two 50 m (160 ft) long preformed concrete box sections, which were jacked through as the excavation proceeded. This created a 23 m (75 ft) wide by 9.5 m (31 ft) high concrete culvert which can be seen from

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