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86-929: Castle Gatehouse, Washington Aqueduct is a pumping station at the Georgetown Reservoir on the Washington Aqueduct in The Palisades neighborhood of Washington, D.C. , United States . The building is on the National Register of Historic Places and contributes to the Washington Aqueduct National Historic Landmark . In 1852 the United States Congress authorized the Army Corps of Engineers to construct

172-431: 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. A pound lock is most commonly used on canals and rivers today. A pound lock has

258-419: A fish ladder are often taken to counteract this. Navigation locks have also potential to be operated as fishways to provide increased access for a range of biota. Locks can be built side by side on the same waterway. This is variously called doubling , pairing , or twinning . The Panama Canal has three sets of double locks. Doubling gives advantages in speed, avoiding hold-ups at busy times and increasing

344-424: A sewer force main if the sewage is transported some significant distance. The pumping station may be called a lift station if the pump merely discharges into a nearby gravity manhole. From here the cycle starts all over again until the sewage reaches its point of destination—usually a treatment plant. By this method, pumping stations are used to move waste to higher elevations. In the case of high sewage flows into

430-402: A well into a reservoir Used to pump drinking water from a reservoir into a water supply system. Canal lock 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

516-569: A boat in a lock. One incident, which took place in June 1873 on the Chesapeake and Ohio Canal, involved the boat the Henry C. Flagg and its drunk captain. That boat was already leaking; the crew, having partially pumped the water out, entered Lock 74, moving in front of another boat. Because they failed to snub the boat, it crashed into and knocked out the downstream gates. The outrush of water from

602-470: A boat in the lock. A 200-ton boat moving at a few miles an hour could destroy the lock gate. To prevent this, a rope was wound around the snubbing post as the boat entered the lock. Pulling on the rope slowed the boat, due to the friction of the rope against the post. A rope 2 + 1 ⁄ 2 inches (6.4 cm) in diameter and about 60 feet (18 meters) long was typically used on the Erie Canal to snub

688-500: A boat travelling upstream, the process is reversed; the boat enters the empty lock, and then the chamber is filled by opening a valve that allows water to enter the chamber from the upper level. The whole operation will usually take between 10 and 20 minutes, depending on the size of the lock and whether the water in the lock was originally set at the boat's level. Boaters approaching a lock are usually pleased to meet another boat coming towards them, because this boat will have just exited

774-528: A broad canal for more than one boat to be in a staircase at the same time, but managing this without waste of water requires expertise. On English canals, a staircase of more than two chambers is usually staffed: the lockkeepers at Bingley (looking after both the "5-rise" and the "3-rise") ensure that there are no untoward events and that boats are moved through as speedily and efficiently as possible. Such expertise permits miracles of boat balletics: boats travelling in opposite directions can pass each other halfway up

860-401: A chain off of the duckfoot and up the two guide rails to the maintenance (normally ground) level. Reinstalling the pumps simply reverses this process with the pump being remounted on the guide rails and lowered onto the duckfoot where the weight of the pump reseals it. As the motors are sealed and weather is not a concern, no above ground structures are required, excepting a small kiosk to contain

946-566: 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 CE), having been pioneered by the Song politician and naval engineer Qiao Weiyue in 984. They replaced earlier double slipways that had caused trouble and are mentioned by

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1032-598: A concept pioneered during the Victorian era in places like The Fens in the UK. The introduction of "package pumping stations" has modernized drainage systems, allowing a compact, efficient solution for areas where gravity drainage is impractical. Water pumping stations are differentiated by their applications, such as sourcing from wells, raw water pumping, and high service pumping, each designed to meet specific demand projections and customer needs. Wastewater pumping stations, on

1118-459: A dry well or pump house and usually consist only of a wet well. In this configuration, submersible sewage pumps with closely coupled electric motor are mounted within the wet well itself, submerged within the sewage. Submersible pumps are mounted on two vertical guide rails and seal onto a permanently fixed "duckfoot", which forms both a mount and also a vertical bend for the discharge pipe. For maintenance or replacement, submersible pumps are raised by

1204-426: A flight of locks is simply a series of locks in close-enough proximity to be identified as a single group. For many reasons, a flight of locks is preferable to the same number of locks spread more widely: crews are put ashore and picked up once, rather than multiple times; transition involves a concentrated burst of effort, rather than a continually interrupted journey; a lock keeper may be stationed to help crews through

1290-412: A gate, or pair of half-gates, traditionally made of oak or elm but now usually made of steel ). The most common arrangement, usually called miter gates , was invented by Leonardo da Vinci sometime around the late 15th century. On the old Erie Canal , there was a danger of injury when operating the paddles: water, on reaching a certain position, would push the paddles with a force which could tear

1376-437: A high-level alarm indication, in the event of pump failure; and possibly a guide-rail/auto-coupling/pedestal system, to permit easy removal of pumps for maintenance. Traditional site constructed systems have the valve vault components installed in a separate structure. Having two structural components can lead to potentially serious site problems such as uneven settling between components which results in stress on, and failure of

1462-403: A large open passage so as to avoid clogging with debris or winding stringy debris onto the impeller. A four pole or six pole AC induction motor normally drives the pump. Rather than provide large open passages, some pumps, typically smaller sewage pumps, also macerate any solids within the sewage breaking them down into smaller parts which can more easily pass through the impeller. The interior of

1548-421: A lock. To help boats traveling downstream exit a lock, the locksman would sometimes open the paddles to create a swell, which would help "flush" the boat out of the lock. A boatsman might ask for a back swell, that is, to open and shut the paddles a few times to create some waves, to help him get off the bank where he was stuck. If boats ran aground (from being overloaded) they sometimes asked passing crews to tell

1634-457: A sewage pump station is a very dangerous place. Poisonous gases, such as methane and hydrogen sulfide , can accumulate in the wet well; an ill-equipped person entering the well would be overcome by fumes very quickly. Any entry into the wet well requires the correct confined space entry method for a hazardous environment. To minimize the need for entry, the facility is normally designed to allow pumps and other equipment to be removed from outside

1720-430: A short way into the chamber from below the upper gates. Allowing the rear of the boat to "hang" on the cill is the main danger when descending a lock, and the position of the forward edge of the cill is usually marked on the lock side by a white line. The edge of the cill is usually curved, protruding less in the center than at the edges. In some locks, there is a piece of oak about 9 in (23 cm) thick which protects

1806-511: A specific pump controller. RTUs are very helpful in remote monitoring of each pumping station from a centralized control room with SCADA (Supervisory Control & Data Acquisition) systems. This setup can be helpful in monitoring pump faults, levels, and other alarms and parameters, making it more efficient. A pumped-storage scheme is a type of power station for storing and producing electricity to supply high peak demands by moving water between reservoirs at different elevations. Typically, water

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1892-480: A staircase lock can be used as an emergency dry dock). To avoid these mishaps, it is usual to have the whole staircase empty before starting to descend, or full before starting to ascend, apart from the initial chamber. One striking difference in using a staircase of either type (compared with a single lock, or a flight) is the best sequence for letting boats through. In a single lock (or a flight with room for boats to pass) boats should ideally alternate in direction. In

1978-404: A staircase, however, it is quicker for a boat to follow a previous one going in the same direction. Partly for this reason staircase locks such as Grindley Brook, Foxton, Watford and Bratch are supervised by lockkeepers, at least during the main cruising season, they normally try to alternate as many boats up, followed by down as there are chambers in the flight. As with a flight, it is possible on

2064-454: A swell to anyone to help them on the way, but some would ask for money for the swell. The Erie Canal management did not like swelling for two reasons. First, it used too much water lowering the water on the pound above sometimes causing boats to run aground. In addition, it raised the water level on the pound below, causing some boats to strike bridges or get stuck. On horse-drawn and mule-drawn canals, snubbing posts were used to slow or stop

2150-480: A water supply for the city of Washington, using the Potomac River at Great Falls as its source. Construction of a 12-mile pipeline began in 1853, and portions of the system began operation in 1859. Little Falls Branch was used as an interim source until the pipeline was completed in 1864. The water was routed to Dalecarlia Reservoir , followed by Georgetown Reservoir . Improvements to the water system in

2236-516: Is a list of those described in this encyclopedia. In the UK, during the Victorian Era , there was a fashion for public buildings to feature highly ornate architecture . Consequently, a considerable number of former pumping stations have been listed and preserved. The majority were originally steam-powered, and where the steam engines are still in situ , many of the sites have since re-opened as museum attractions. Used to pump water from

2322-426: Is a normal top gate, and the intermediate gates are all as tall as the bottom gate). As there is no intermediate pound, a chamber can only be filled by emptying the one above, or emptied by filling the one below: thus the whole staircase has to be full of water (except for the bottom chamber) before a boat starts to ascend, or empty (except for the top chamber) before a boat starts to descend. In an "apparent" staircase

2408-407: Is available, back pumping systems may be employed. Water is extracted from the canal below the lowest lock of a flight and is pumped back to the top of the flight, ready for the next boat to pass through. Such installations are usually small. When low-lying areas of land are drained, the general method is to dig drainage ditches . However, if the area is below sea level then it is necessary to pump

2494-479: Is built into the system so that in the event that any one pump is out of service, the remaining pump or pumps will handle the designed flow. The storage volume of the wet well between the "pump on" and "pump off" settings is designed to minimize pump starts and stops, but is not so long a retention time as to allow the sewage in the wet well to go septic . Sewage pumps are almost always end-suction centrifugal pumps with open impellers and are specially designed with

2580-409: Is channeled from a high-level reservoir to a low-level reservoir, through turbine generators that generate electricity. This is done when the station is required to generate power. During low-demand periods, such as overnight, the generators are reversed to become pumps that move the water back up to the top reservoir. There are countless thousands of pumping stations throughout the world. The following

2666-431: Is fed from underground gravity pipelines (pipes that are sloped so that a liquid can flow in one direction under gravity). Sewage is fed into and stored in a pit, commonly known as a wet well . The well is equipped with electrical instrumentation to detect the level of sewage present. When the sewage level rises to a predetermined point, a pump will be started to lift the sewage upward through a pressurized pipe system called

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2752-451: Is not possible. A package pumping station is an integrated system, built in a housing manufactured from strong, impact-resistant materials such as precast concrete , polyethylene , or glass-reinforced plastic . The unit is supplied with internal pipework fitted, pre-assembled ready for installation into the ground, after which the submersible pumps and control equipment are fitted. Features may include controls for fully automatic operation;

2838-443: Is only a staircase if successive lock chambers share a gate (i.e. do not have separate top and bottom gates with a pound between them). Most flights are not staircases, because each chamber is a separate lock (with its own upper and lower gates), there is a navigable pound (however short) between each pair of locks, and the locks are operated in the conventional way. However, some flights include (or consist entirely of) staircases. On

2924-881: The Bollène lock on the River Rhône has a fall of at least 23 m (75 ft), the Leerstetten, Eckersmühlen and Hilpoltstein locks on the Rhine–Main–Danube Canal have a fall of 24.67 m (80.9 ft), each and the Oskemen Lock on the Irtysh River in Kazakhstan has a drop of 42 m (138 ft). The natural extension of the flash lock , or staunch, was to provide an upper gate (or pair of gates) to form an intermediate "pound" which

3010-472: The Caledonian Canal the lock gates were operated by man-powered capstans , one connected by chains to open the gate and another to draw it closed. By 1968 these had been replaced by hydraulic power acting through steel rams. The construction of locks (or weirs and dams) on rivers obstructs the passage of fish. Some fish such as lampreys, trout and salmon go upstream to spawn. Measures such as

3096-634: The Claverton and Crofton Pumping Stations , are preserved as museum attractions. Examples such as land drainage in the Netherlands water supply in Hong Kong and agricultural drainage in Iraq, underscore the vital role these facilities play in supporting modern infrastructure, environmental management, and energy storage. In countries with canal systems, pumping stations are also frequent. Because of

3182-898: The Corps of Engineers insignia . Portland cement plaster was used to replicate stonework and give the gatehouse an authentic castle appearance. The gatehouse is managed by the Army Corps of Engineers, Baltimore District. The building was added to the National Register of Historic Places on March 13, 1975. Pumping station Pumping stations are designed to move water or sewage from one location to another, overcoming gravitational challenges, and are essential for maintaining navigable canal levels, supplying water, and managing sewage and floodwaters. In canal systems, pumping stations help replenish water lost through lock usage and leakage, ensuring navigability. Similarly, in land drainage, stations pump water to prevent flooding in areas below sea level,

3268-476: The Grand Union . Operation of a staircase is more involved than a flight. Inexperienced boaters may find operating staircase locks difficult. The key worries (apart from simply being paralysed with indecision) are either sending down more water than the lower chambers can cope with (flooding the towpath, or sending a wave along the canal) or completely emptying an intermediate chamber (although this shows that

3354-722: The Rochdale Canal , which both have a rise of nearly 20 feet (6.1 m). Both locks are amalgamations of two separate locks, which were combined when the canals were restored to accommodate changes in road crossings. By comparison, the Carrapatelo and Valeira locks on the Douro river in Portugal, which are 279 feet (85 m) long and 39 feet (12 m) wide, have maximum lifts of 115 and 108 feet (35 and 33 m) respectively. The two Ardnacrusha locks near Limerick on

3440-598: The Song dynasty (960–1279 CE). The Songshi or History of the Song Dynasty, volume 307, biography 66, records how Qiao Weiyue, a high-ranking tax administrator, was frustrated at the frequent losses incurred when his grain barges were wrecked on the West River near Huai'an in Jiangsu . The soldiers at one double slipway, he discovered, had plotted with bandits to wreck heavy imperial barges so that they could steal

3526-520: The Chinese polymath Shen Kuo (1031–1095) in his book Dream Pool Essays (published in 1088), and fully described in the Chinese historical text Song Shi (compiled in 1345): The distance between the two locks was rather more than 50 paces, and the whole space was covered with a great roof like a shed. The gates were 'hanging gates'; when they were closed the water accumulated like a tide until

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3612-567: The Grand Union (Leicester) Canal, the Watford flight consists of a four-chamber staircase and three separate locks; and the Foxton flight consists entirely of two adjacent 5-chamber staircases. Where a very steep gradient has to be climbed, a lock staircase is used. There are two types of staircase, "real" and "apparent". A "real" staircase can be thought of as a "compressed" flight, where

3698-522: The Shannon navigation in Ireland have a rise of 100 feet (30 m). The upper chamber rises 60 feet (18 m) and is connected to the lower chamber by a tunnel, which when descending does not become visible until the chamber is nearly empty. A pound is the level stretch of water between two locks (also known as a reach ). The cill , also spelled sill , is a narrow horizontal ledge protruding

3784-585: The accumulation of sedimentary mud that created the land initially. Elsewhere, pumping stations are used to remove water that has found its way into low-lying areas as a result of leakage or flooding (in New Orleans , for example). In more recent times, a "package pumping station" provides an efficient and economic way of installing a drainage system. They are suitable for mechanical building services collection and pumping of liquids like surface water, wastewater or sewage from areas where drainage by gravity

3870-475: The advent of canals in Britain. The sides of the turf-lock are sloping so, when full, the lock is quite wide. Consequently, this type of lock needs more water to operate than vertical-sided brick- or stone-walled locks. On British canals and waterways most turf-sided locks have been subsequently rebuilt in brick or stone, and so only a few good examples survive, such as at Garston Lock , and Monkey Marsh Lock , on

3956-471: The bottom cill at all but the higher tides – the new bottom chamber rises just far enough to get the boat over the original lock cill. In China, the recently completed Three Gorges Dam includes a double five-step staircase for large ships, and a ship lift for vessels of less than 3000 metric tons. Examples of "apparent" staircases are Foxton Locks and Watford Locks on the Leicester Branch of

4042-641: The canal would cause frequent interruptions of the heavy road traffic. It can be emptied by pumping – but as this uses a lot of electricity the method used when water supplies are adequate is to drain the lock to a nearby burn . In 2016 the Kieldrecht Lock in the Port of Antwerp in Belgium took over the title of the world's largest lock from the Berendrecht Lock in the same port and still has

4128-599: The chambers so that some water from the emptying chamber helps to fill the other. This facility has long been withdrawn on the English canals, although the disused paddle gear can sometimes be seen, as at Hillmorton on the Oxford Canal . Elsewhere they are still in use; a pair of twinned locks was opened in 2014 on the Dortmund–Ems Canal near Münster , Germany. The once-famous staircase at Lockport, New York ,

4214-631: The chambers still have common gates, but the water does not pass directly from one chamber to the next, going instead via side ponds. This means it is not necessary to ensure that the flight is full or empty before starting. Examples of famous "real" staircases in England are Bingley and Grindley Brook . Two-rise staircases are more common: Snakeholme Lock and Struncheon Hill Lock on the Driffield Navigation were converted to staircase locks after low water levels hindered navigation over

4300-404: The chance of a boat finding a lock set in its favour. There can also be water savings: the locks may be of different sizes, so that a small boat does not need to empty a large lock; or each lock may be able to act as a side pond (water-saving basin) for the other. In this latter case, the word used is usually "twinned": here indicating the possibility of saving water by synchronising the operation of

4386-523: The concept has been suggested in a number of cases, the only example in the world of a drop lock that has actually been constructed is at Dalmuir on the Forth and Clyde Canal in Scotland. This lock, of the single-chamber type, was incorporated during the restoration of the canal, to allow the replacement of a swing bridge (on a busy A road) by a fixed bridge, and so answer criticisms that the restoration of

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4472-450: The demand or projected demand is reasonably defined, and is dependent on a combination of customer needs and fire flow requirements. Average annual per-capita water consumption, peak hour, and maximum daily can vary greatly due to factors such as climate, income levels, population, and the proportions of residential, commercial, and industrial users. Pumping stations in sewage collection systems are normally designed to handle raw sewage that

4558-458: The efficiency and monitoring capabilities of pumping stations, essential for modern systems. Pumped-storage schemes represent a critical use of pumping stations, providing a method for energy storage and generation by moving water between reservoirs at different elevations, highlighting the versatility and importance of pumping stations across sectors. Some pumping stations have been recognized for their architectural and historical significance, e.g.

4644-417: The electrical switchgear and control systems. Due to the much reduced health and safety concerns, and smaller footprint and visibility, submersible pump sewage pumping stations have almost completely superseded traditional sewage pumping stations. Further, a refit of a traditional pumping station usually involves converting it into a modern pumping station by installing submersibles in the wet well, demolishing

4730-452: The first to solve the problem of keeping the Nile free of salt water when his engineers invented the lock around 274/273 BC. All pound locks have three elements: The principle of operating a lock is simple. For instance, if a boat travelling downstream finds the lock already full of water: If the lock were empty, the boat would have had to wait 5 to 10 minutes while the lock was filled. For

4816-617: The first true pound lock was built in 1396 at Damme near Bruges , Belgium. The Italian Bertola da Novate (c. 1410–1475) constructed 18 pound locks on the Naviglio di Bereguardo (part of the Milan canal system sponsored by Francesco Sforza ) between 1452 and 1458. In Ancient Egypt, the river-locks was probably part of the Canal of the Pharaohs : Ptolemy II is credited by some for being

4902-425: The flight quickly; and where water is in short supply, a single pump can recycle water to the top of the whole flight. The need for a flight may be determined purely by the lie of the land, but it is possible to group locks purposely into flights by using cuttings or embankments to "postpone" the height change. Examples: Caen Hill locks, Devizes . "Flight" is not synonymous with "Staircase" (see below). A set of locks

4988-518: The form of the now-disused Écluse des Lorraines , connecting the Canal latéral à la Loire with the River Allier . A drop lock can consist of two conventional lock chambers leading to a sump pound, or a single long chamber incorporating the sump – although the term properly applies only to the second case. As the pounds at either end of the structure are at the same height, the lock can only be emptied either by allowing water to run to waste from

5074-531: The inside walls of the lock with wood, so as not to abrade the boats. This was done, for instance, on the Chesapeake and Ohio Canal with the locks near the Paw Paw Tunnel . and also the Chenango Canal On large modern canals, especially very large ones such as ship canals , the gates and paddles are too large to be hand operated, and are operated by hydraulic or electrical equipment. On

5160-414: The intermediate pounds have disappeared, and the upper gate of one lock is also the lower gate of the one above it. However, it is incorrect to use the terms staircase and flight interchangeably: because of the absence of intermediate pounds, operating a staircase is very different from operating a flight. It can be more useful to think of a staircase as a single lock with intermediate levels (the top gate

5246-555: The late 19th century included the Castle Gatehouse. The gatehouse was constructed at the Georgetown Reservoir to pump water into the four-mile long Washington City Tunnel that led to McMillan Reservoir , completed in 1902. A filtration system was constructed at McMillan in 1905 and this system improved the quality of city water. Construction of the gatehouse began in 1899. The design was intended to replicate

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5332-450: The lock caused the upstream gates to slam shut, breaking them also, and sending a cascade of water over the boat, sinking it. This suspended navigation on the canal for 48 hours until the lock gates could be replaced and the boat removed from the lock. To economise, especially where good stone would be prohibitively expensive or difficult to obtain, composite locks were made, i.e. they were constructed using rubble or inferior stone, dressing

5418-465: The lock on their level and therefore set the lock in their favour – saving about 5 to 10 minutes. However, this is not true for staircase locks, where it is quicker for boats to go through in convoy, and it also uses less water. The rise is the change in water-level in the lock. The two deepest locks on the English canal system are Bath deep lock on the Kennet and Avon Canal and Tuel Lane Lock on

5504-688: The new canal was low. This resulted in a sequential pair of locks, with gates pointing in opposite directions: one example was at Hall Green near Kidsgrove , where the southern terminus of the Macclesfield Canal joined the Hall Green Branch of the earlier Trent and Mersey Canal . The four gate stop lock near Kings Norton Junction, between the Stratford-upon-Avon Canal and the Worcester and Birmingham Canal

5590-412: The other hand, are engineered to handle sewage, with designs that ensure reliability and safety, minimizing environmental impacts from overflows. Innovations in pump technology and station design have led to the development of submersible pump stations, which are more compact and safer, effectively reducing the footprint and visibility of sewage management infrastructure. Electronic controllers have enhanced

5676-571: The pipes and connections between components. The development of a packaged pump station system combined all components into a single housing which not only eliminates uneven settling issues, but pre-plumbing and outfitting each unit prior to installation can reduce the cost and time involved with civil work and site labor. Water pumping stations are differentiated from wastewater pumping stations in that they do not have to be sized to account for high peak flow rates. They have five general categories: Water pumping stations are constructed in areas in which

5762-479: The pump house and retiring the dry well by either stripping it, or knocking down the internal partition and merging it with the wet well. Pump manufacturers have always designed and manufactured electronic devices to control and supervise pumping stations. Today it is also very common to use a programmable logic controller (PLC) or Remote Terminal Unit (RTU) for such work, but the experience needed to solve certain particular problems, makes an easy choice to look for

5848-467: The required level was reached, and then when the time came it was allowed to flow out. The water level could differ by 4 or 5 feet (1.2 or 1.5 m) at each lock and in the Grand Canal the level was raised in this way by 138 feet (42 m). In medieval Europe a sort of pound lock was built in 1373 at Vreeswijk , Netherlands. This pound lock serviced many ships at once in a large basin . Yet

5934-418: The sewage in the wet well, dry wells are underground, confined spaces and require appropriate precautions for entry. Further, any failure or leakage of the pumps or pipework can discharge sewage directly into the dry well with complete flooding not an uncommon occurrence. As a result, the electric motors are normally mounted above the overflow, top water level of the wet well, usually above ground level, and drive

6020-403: The sewage pumps through an extended vertical shaft. To protect the above ground motors from weather, small pump houses are normally built, which also incorporate the electrical switchgear and control electronics. These are the visible parts of a traditional sewage pumping station although they are typically smaller than the underground wet and dry wells. More modern pumping stations do not require

6106-649: The solid part of the lock cill. On the Oxford Canal it is called a babbie; on the Grand Union Canal it is referred to as the cill bumper. Some canal operation authorities, primarily in the United States and Canada, call the ledge a miter sill (mitre sill in Canada). Gates are the watertight doors which seal off the chamber from the upper and lower pounds. Each end of the chamber is equipped with

6192-407: The spilled grain. In 984 Qiao installed a pair of sluice-gates two hundred and fifty feet apart, the entire structure roofed over like a building. By siting two staunch gates so close to one another, Qiao had created a short stretch of canal, effectively a pound-lock, filled from the canal above by raising individual wooden baulks in the top gate and emptied into the canal below by lowering baulks in

6278-411: The staircase by moving sideways around each other; or at peak times, one can have all the chambers full simultaneously with boats travelling in the same direction. When variable conditions meant that a higher water level in the new canal could not be guaranteed, then the older company would also build a stop lock (under its own control, with gates pointing towards its own canal) which could be closed when

6364-413: The sump to a lower stream or drain, or (less wastefully) by pumping water back up to the canal. Particularly in the two-chamber type, there would be a need for a bypass culvert, to allow water to move along the interrupted pound and so supply locks further down the canal. In the case of the single-chamber type, this can be achieved by keeping the lock full and leaving the gates open while not in use. While

6450-493: The title for largest volume. In 2022 the IJmuiden sea lock serving the Port of Amsterdam became the world's largest lock by surface area. The lock is 500 m (1,600 ft) long, 70 m (230 ft) wide and has sliding lock gates creating a usable depth of 18 m (59 ft). The size of locks cannot be compared without considering the difference in water level that they are designed to operate under. For example,

6536-400: The top gate and raising ones in the lower. A turf-sided lock is an early form of canal lock design that uses earth banks to form the lock chamber, subsequently attracting grasses and other vegetation, instead of the now more familiar and widespread brick, stone, or concrete lock wall constructions. This early lock design was most often used on river navigations in the early 18th century before

6622-506: The upper parts of the canal, but if no suitable source is available, a pumping station can be used to maintain the water level. An example of a canal pumping station is the Claverton Pumping Station on the Kennet and Avon Canal in southern England, United Kingdom. This pumps water from the nearby River Avon to the canal using pumps driven by a waterwheel which is powered by the river. Where no external water supply

6708-404: The upstream lock to give them an extra heavy swell, which consisted of opening all the paddles on the lock gate, creating a surge that affected the whole pound below. On the Erie Canal, some loaded boats needed a swell to get out of the lock. Particularly lumber boats, being top heavy, would list to one side and get stuck in the lock, and needed a swell to get them out. Some lockkeepers would give

6794-476: The water upwards into water channels that finally drain into the sea. The Victorians understood this concept, and in the United Kingdom they built pumping stations with water pumps , powered by steam engines to accomplish this task. In Lincolnshire, large areas of wetland at sea level, called The Fens , were turned into rich arable farmland by this method. The land is full of nutrients because of

6880-431: The way the system of canal locks work, water is lost from the upper part of a canal each time a vessel passes through. Also, most lock gates are not watertight, so some water leaks from the higher levels of the canal to those lower down. The water has to be replaced or eventually the upper levels of the canal would not hold enough water to be navigable. Canals are usually fed by diverting water from streams and rivers into

6966-438: The well (for example during peak flow periods and wet weather) additional pumps will be used. If this is insufficient, or in the case of failure of the pumping station, a backup in the sewer system can occur, leading to a sanitary sewer overflow —the discharge of raw sewage into the environment. Sewage pumping stations are typically designed so that one pump or one set of pumps will handle normal peak flow conditions. Redundancy

7052-404: The wet well. Traditional sewage pumping stations incorporate both a wet well and a "dry well". Often these are the same structure separated by an internal divide. In this configuration pumps are installed below ground level on the base of the dry well so that their inlets are below water level on pump start, priming the pump and also maximising the available NPSH . Although nominally isolated from

7138-405: The windlass (or handle) out of one's hands, or if one was standing in the wrong place, could knock one into the canal, leading to injuries and drownings. On the Chesapeake and Ohio Canal, the lockkeepers were required to remove the windlasses from all lock paddles at night, to prevent unauthorized use. A swell was caused by opening suddenly the paddle valves in the lock gates, or when emptying

7224-463: Was all that need be emptied when a boat passed through. This type of lock, called a pound lock was known in Imperial China and ancient Europe and was used by Greek engineers in the Canal of the Pharaohs under Ptolemy II (284 to 246 BC), when engineers solved the problem of overcoming the difference in height through canal locks . Pound locks were first used in medieval China during

7310-416: Was also a doubled set of locks. Five twinned locks allowed east- and west-bound boats to climb or descend the 60 feet (18 m) Niagara Escarpment , a considerable engineering feat in the nineteenth century. While Lockport today has two large steel locks, half of the old twin stair acts as an emergency spillway and can still be seen, with the original lock gates having been restored in early 2016. Loosely,

7396-606: Was replaced in 1914 by a pair of guillotine lock gates which stopped the water flow regardless of which canal was higher. These gates have been permanently open since nationalisation. The best known example of a round lock is the Agde Round Lock on the Canal du Midi in France. This serves as a lock on the main line of the canal and allows access to the Hérault River . A second French round lock can be found in

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