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122-688: Boulter's Lock is a lock and weir on the River Thames in England north-east of Maidenhead town centre, Berkshire . The present 1912-built lock replaces those at this point of the river to the immediate east dating from the late 16th century and that of 1772 built by the Thames Navigation Commission . The lock is on the western side of the north–south flowing reach between the A4094 Maidenhead to Cookham road and Ray Mill Island . The name

244-718: 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 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

366-404: 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 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

488-528: 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

610-416: A cost of £1,630. A separate contract for the masonry and millwright's work was given to Clarke and Moss, while carpentry and general labouring was done by men employed directly by the commission. Stone was obtained from Headington Quarry near Oxford . Because of the distance from the fall below to the lock, a separate 6 hp (4.5 kW) steam engine was used in operation post-building to pump out (lower)

732-464: A factory, handrails are constructed by feeding rubber through an extrusion machine to produce layers of the required size and type in order to match specific orders. The component layers of fabric, rubber and steel are shaped by workers before being fed into the presses which fuse them together. In the mid-twentieth century, some handrail designs consisted of a rubber bellows, with rings of smooth metal cladding called "bracelets" between each coil. This gave

854-426: 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

976-460: A handhold for passengers while they are riding the escalator. The handrail is pulled along its own track by a chain that is connected to the main drive gear by a series of pulleys, keeping it at the same speed as the steps. Four distinct sections make up the rail: at its center is a "slider", also known as a "glider ply", which is a layer of a cotton or synthetic textile that allows the rail to move smoothly along its track. The " tension member " lies on

1098-480: 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 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

1220-523: 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 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

1342-594: A mill is known to have existed here in the 14th century. The flash lock was located in what is now the main weir, with a winch to haul barges through on the west bank near the tip of Boulter's Island. In 1746 it was written that there was no (extant) lock further downstream on the Thames. The Navigation Act obtained in April 1771 did not allow the Thames Navigation Commission to build locks below Maidenhead Bridge , so

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1464-432: A single-width escalator traveling at about 0.5 metres per second ( 1 + 1 ⁄ 2  ft/s) can move about 2000 people per hour, assuming that passengers ride single file. The carrying capacity of an escalator system is typically matched to the expected peak traffic demand. For example, escalators at transit stations must be designed to cater for the peak traffic flow discharged from a train, without excessive bunching at

1586-534: A spiral escalator by 1973. When interviewed for the Los Angeles Times that year, Luna was in the process of soliciting major firms for the acquisition of his patents and company, but statistics are unclear on the outcome of these endeavors. Karl-Heinz Pahl received a European and a US patent for a spiral escalator in 1992. The Mitsubishi Electric Corporation was most successful in its development of spiral or helical escalators, and it alone has sold them since

1708-480: 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

1830-404: 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

1952-400: A staircase; a ladder, [or] a scaling-ladder." The alleged intended capitalization of "escalator" is likewise a topic of debate. Seeberger's trademark application lists the word not only with the "E", but also with all of the letters capitalized (in two different instances), and he specifies that "any other form and character of type may be employed... without altering in any essential manner

2074-432: A time, and then exploded into the ticket hall above in a previously unrecognised phenomenon now known as the " trench effect ". In the escalators' undercarriage, approximately 8,800 kilograms (19,400 lb) of accumulated detritus acted as a wick to a neglected buildup of interior lubricants; wood veneers, paper and plastic advertisements, solvent-based paint, plywood in the ticket hall, and melamine combustion added to

2196-477: A title for it. As evidenced in Seeberger's handwritten documents, the inventor consulted "a Latin lexicon" and "adopted as the root of the new word, 'Scala'; as a prefix, 'E' and as a suffix, 'Tor.'" His own rough translation of the word thus created was "means of traversing from", and he intended for the word to be pronounced / ɛ s ˈ k æ l ə t ɔːr / ( ess- KAL -ə-tor ). By 1906, Seeberger noted that

2318-400: 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 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

2440-426: 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

2562-451: Is also sometimes provided by adding automatic sprinklers or fireproof shutters to the opening, or by installing the escalator in an enclosed fire-protected space. The King's Cross fire of 1987 illustrated the demanding nature of escalator upkeep and the devices' propensity to collect "fluff" and other small debris when not properly maintained. The official inquiry determined that the fire started slowly, smoldering virtually undetected for

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2684-439: Is credited with patenting the first "escalator" in 1859, even though no working model of his design was ever built. His invention, the "revolving stairs", is largely speculative and the patent specifications indicate that he had no preference for materials or potential use (he noted that steps could be upholstered or made of wood, and suggested that the units might benefit the infirm within a household use). The suggested motive power

2806-511: Is his Boulter's Lock, Sunday afternoon . Nicholas Pocock , the marine artist, lived at 'Ray Lodge' and broadcaster Richard Dimbleby had a house on Boulter's Island . Author John O'Farrell , grew up in 'The Weir House' opposite. The Mr Bean episode Tee Off Mr Bean was recorded in a miniature golf course next to Boulter's Lock. 51°32′00″N 0°41′58″W  /  51.53329°N 0.69954°W  / 51.53329; -0.69954 Lock (water transport) Locks are used to make

2928-443: 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

3050-432: Is separated and load/unload areas are other important considerations. Temporal traffic patterns must be anticipated. Some escalators need only to move people from one floor to another, but others may have specific requirements, such as funneling visitors towards exits or exhibits. The visibility and accessibility of the escalator to traffic is relevant. Designers need to account for the projected traffic volumes. For example,

3172-559: 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 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,

3294-465: Is the hollow metal structure that bridges the lower and upper landings, composed of two side sections joined with cross braces across the bottom and just below the top. The ends of the truss are attached to the top and bottom landing platforms via steel or concrete supports. It carries all the straight track sections connecting the upper and lower sections. The balustrade is composed of handrails, balustrade panels, and skirt panels. The handrail provides

3416-463: Is variably used for the immediate surrounding area. The weir is some way upstream of the lock, at the northern end of Ray Mill Island. It is one of the most popular whitewater freestyle kayaking areas on the River Thames, as it has been modified to allow kayakers to use it without causing disruption to other river users. The earliest reference to a flash lock is in the late 16th century, although

3538-846: 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

3660-601: The Boston subway until construction for the Big Dig ( c.  1991 ) precipitated their removal. The Smithsonian Institution considered re-assembling one of these historic units from 1914 in their collection of Americana, but "logistics and reassembly costs won out over nostalgia", and the project was discarded. Around May 1895, Charles Seeberger began drawings on a form of escalator similar to those patented by Wheeler in 1892. This device consisted of flat, moving stairs, not unlike

3782-471: The Duke of Wellington was the last of a series built on the Thames. The last salmon caught at the weir was landed on 5 August 1993. It is to this day the largest salmon in recorded history caught on the non-tidal River Thames and weighed 14lb's, measuring 97 cm's in length. Ray Mead road/Lower Cookham road (A4094) runs alongside the lock. There is a public car park about 100m north of the lock. A track runs onto

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3904-614: The Fahrtreppe in 1906. After the Exposition , Hallé continued to sell its escalator device in Europe but was eventually eclipsed in sales by other major manufacturers. In the first half of the twentieth century, several manufacturers developed their own escalator products, though they had to market their devices under different names, due to Otis’ hold on the trademark rights to the word "escalator." New York -based Peelle Company called their models

4026-470: 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

4148-662: The Kennet and Avon Canal . Escalator An escalator is a moving staircase which carries people between floors of a building or structure. It consists of a motor -driven chain of individually linked steps on a track which cycle on a pair of tracks which keep the step tread horizontal. Escalators are often used around the world in places where lifts would be impractical, or they can be used in conjunction with them. Principal areas of usage include department stores , shopping malls , airports , transit systems (railway/railroad stations), convention centers , hotels , arenas , stadiums and public buildings. Escalators have

4270-688: The London Transport Museum 's depot in Acton . Although the first fully operational spiral escalator, Reno's design was nonetheless only one in a series of similar proposed contraptions. Souder patented two helical designs, while Wheeler drafted helical stairway plans in 1905. Seeberger devised at least two helical designs between 1906 and 1911 (including an unrealized arrangement for the London Underground), and Gilbert Luna obtained West German, Japanese, and United States patents for his version of

4392-596: 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 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

4514-524: The Prague metro , escalator users are encouraged to stand on whichever side they choose, with the aim of preventing wear and tear and asymmetrical burdening. All Tokyo metro stations also have posters next to the escalators that ask users not to walk but instead to stand on either side. The practice of standing on one side and walking on the other may cause uneven wear on escalator mechanisms. Transport for London trialed standing on both sides (no walking) for

4636-581: 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

4758-538: The 1930s, at least one suit was filed against a department store, alleging that its escalators posed an attractive nuisance , responsible for a child's injury. Despite their considerable scope, the two Congressional Acts regarding accessibility (the Rehabilitation Act of 1973 and the Americans with Disabilities Act of 1990 (ADA) ) did not directly affect escalators or their public installations. Since Section 504 of

4880-478: The 1970s, buying out Swedish elevator manufacturer Asea-Graham , and purchasing other minor French, German and Austrian elevator makers before assuming control of Westinghouse's European elevator business. As the last of the "big four" manufacturers to emerge onto the global market, Kone first acquired the Montgomery Elevator company, then took control of Germany's Orenstein & Koppel Rolltreppen . In

5002-664: 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 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

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5124-460: 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 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

5246-542: The Examiner of Trademark Interferences, Assistant Commissioner of Patents Murphy's decision rejected Otis’ appeal to keep their trademark intact, and noted that "the term 'escalator' is recognized by the general public as the name for a moving stairway and not the source thereof", observing that Otis had "used the term as a generic descriptive term... in a number of patents which [had] been issued to them and... in their advertising matter." All trademark protections were removed from

5368-552: 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

5490-594: The Motorstair, while Westinghouse called their model an Electric Stairway. The Toledo -based Haughton Elevator company referred to their product as simply Moving Stairs. The Otis trademark is no longer in effect. Kone and Schindler introduced their first escalator models several decades after the Otis Elevator Co., but grew to dominate the field over time. Today, Mitsubishi and ThyssenKrupp are Otis's primary rivals. Kone expanded internationally by acquisition in

5612-647: The Old Iron Pier at Coney Island , New York City in 1896. This particular device was little more than an inclined belt with cast-iron slats or cleats on the surface for traction, and traveled along a 25 degree incline. A few months later, the same prototype was used for a month-long trial period on the Manhattan side of the Brooklyn Bridge . Reno eventually joined forces with Otis and retired once he had sold his patents. Some Reno-type escalators were still being used in

5734-818: The Rehabilitation Act included public transportation systems, for a few years, the United States Department of Transportation considered designs to retrofit existing escalators for wheelchair access. Nonetheless, Foster-Miller Associates ' 1980 plan, Escalator Modification for the Handicapped was ultimately ignored in favor of increased elevator installations in subway systems. Likewise, the ADA provided more accessibility options, but expressly excluded escalators as "accessible means of egress", advocating neither their removal nor their retention in public structures. In

5856-757: The United Kingdom, France and the United States are expected to stand on the right and walk on the left. However, in Australia and New Zealand, the opposite is the case. Practice may differ from city to city within countries: in Osaka , riders stand on the right, whereas in Tokyo (and most other Japanese cities), riders stand on the left. In certain high-traffic systems, including the East Japan Railway Company and

5978-496: The United States and Canada, new escalators must abide by ASME A17.1 standards, and old/historic escalators must conform to the safety guidelines of ASME A17.3. In Europe, the escalator safety code is EN 115. In most major countries, the expectation is that escalator users wishing to stand keep to one side to allow others to climb past them on the other. Due to historical design purposes, riders in Canada, Germany, Hong Kong, Taiwan,

6100-470: 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

6222-399: The back wheels of the steps (called the trailer-wheel track). The relative positions of these tracks cause the steps to form a staircase as they move out from under the comb plate. Along the straight section of the truss the tracks are at their maximum distance apart. This configuration forces the back of one step to be at a 90-degree angle relative to the step behind it. This right angle forces

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6344-573: 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 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

6466-463: 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

6588-617: 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

6710-444: The capacity to move large numbers of people. They have no waiting interval (except during very heavy traffic). They can be used to guide people toward main exits or special exhibits and may be weatherproofed for outdoor use. A non-functional escalator can function as a normal staircase, whereas many other methods of transport become useless when they break down or lose power. Nathan Ames , a patent attorney from Saugus, Massachusetts ,

6832-538: 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 ,

6954-567: 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

7076-404: 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

7198-408: The character of [the] trade-mark." Otis Elevator Co. advertisements so frequently capitalized all of the letters in the word. In 1950, the landmark case Haughton Elevator Co. v. Seeberger precipitated the end of Otis's exclusive reign over the word "escalator", and simultaneously created a cautionary study for companies and individuals interested in trademark retention. Confirming the contention of

7320-492: 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 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 ,

7442-533: The company relinquished its patent rights to the department store. Noted by Bill Lancaster in The Department Store: a Social History , "customers unnerved by the experience were revived by shopmen dispensing free smelling salts and cognac." The Harrods unit was a continuous leather belt made of "224 pieces... strongly linked together traveling in an upward direction", and was the first "moving staircase" in England. Hocquardt received European patent rights for

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7564-514: 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

7686-518: The deep hole and subsequent shoals caused by the force of water. In 1825 the City of London Corporation complained regarding condition and recommended it be rebuilt on the Berkshire side of the river. This involved excavating a 600-yard (550 m) lock cut. For drainage during construction, a waterwheel was placed in the weir, which was used to operate pumps. The contract to dig was given to George Gynell, at

7808-401: The ends of the escalator truss. Each platform also has a floor and a comb bearer. The floor plate provides a place for the passengers to stand before they step onto the moving stairs, flush with the rest of the floor and are removable to allow easy engineer access, while the comb bearer sits between the stationary floor plate and the moving step, so named for the cleats on its edge which mesh with

7930-499: The escalator entrance. In this regard, escalators help manage the flow of people. For example, at many airports an unpaired escalator delivers passengers to an exit, with no means for anyone entering at the exit to access the concourse. Escalators are often built next to or around staircases that allow alternative travel between the same two floors. Elevators are necessary for disability access to floors serviced by escalators. Escalators typically rise at an angle of 30 or 35 degrees from

8052-578: The escalator path, avoiding excessive force on the top chain links and hence avoiding the geometry, length, and height limits of standard escalators. Emporium Centre San Francisco , San Francisco, California, United States, is the first spiral escalator in the Western Hemisphere. Levytator, a design originating at City University in London, can move in straight lines or curves with or without rising or descending. The returning steps do not move underneath

8174-434: The escalators of today, except for one important detail: the step surface was smooth, with no comb effect to safely guide the rider's feet off at the ends. Instead, the passenger had to step off sideways. To facilitate this, at the top or bottom of the escalator the steps continued moving horizontally beyond the end of the handrail (like a miniature moving sidewalk) until they disappeared under a triangular "divider" which guided

8296-425: 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

8418-512: 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

8540-428: The ground. They move at 0.3–0.9 metres per second (1–3 ft/s), like moving walkways , and may traverse vertical distances in excess of 18 metres (60 ft). Most modern escalators have single-piece aluminum or stainless steel steps that move on a system of tracks in a continuous loop. Different types of escalator planning include: Most countries require escalators to have moving handrails that keep pace with

8662-441: The handrail a rigid yet flexible feel. Additionally, each bellows section was no more than around a metre long, so if part of the handrail was damaged, only the bad segment needed to be replaced. These forms of handrail have largely been replaced with fabric-and-rubber railings. Being made of either metal, sandwich panel , or glass, the balustrade panel supports the handrails of the escalator. It also provides additional protection for

8784-437: The handrail and passengers. Some escalators have direction arrows on the ends of the balustrade. Escalators' on/off buttons are frequently located at the ends of the balustrade. Moving walkways often use balustrades in the same way. The bottom of the balustrade is called a skirt panel. It is notorious in this art for being a frequent site of injuries and failures, due to the possible entrapment of materials (including body parts) in

8906-581: The impact of the calamity. Following the report, older wooden escalators were removed from service in the London Underground . Additionally, sections of the London Underground that were actually below ground were made non-smoking ; ultimately, the whole system became a smoke-free zone. Some of longest and fastest escalators in Europe are found in Prague , and are set to be replaced with slower versions in order to meet modern safety standards. In

9028-720: The in-use steps: rather, they provide steps for travel in the opposite direction, as in the Pahl spiral escalator patent. Safety is a major concern in escalator design, as escalators are powerful machines that can become entangled with clothing and other items. Such entanglements can injure or kill riders. In India many women wear saris , increasing the likelihood of entangling the clothing's loose end. To prevent this, sari guards are built into most escalators in India. Children wearing footwear such as Crocs and flip-flops are especially at risk of being caught in escalator mechanisms. The softness of

9150-414: 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

9272-486: The lock built here in 1772 was the furthest downstream of the eight first built by the commission. The lock was timber-sided, and the work was overseen by Joseph Nickalls, who had designed a scheme of improvements to the river from Abingdon to Richmond, in preparation for obtaining the act of parliament . Originally the lock was on the Taplow side, close to Taplow Mill. It was referred to as Boltus lock or Bolters lock. A "bolter"

9394-504: The lock chamber. The project was managed by George Treacher, with work beginning in December 1827 and finishing in April 1829. The total cost of the work was £11,800 When completed, the lock's volume – 151 by 19 feet (46.0 by 5.8 m) length with a fall of 6 feet (1.8 m) plus depth of 5 feet (1.5 m) over the sills—was the largest of a pound lock with masonry walls on English river navigations. In recognition of his work, Treacher

9516-403: 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 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

9638-482: The lock island. An hourly bus route to the lock from Maidenhead town centre is run by Courtney Coaches . After the long cut beside the islands the reach opens out at the head of the Jubilee River on the east bank. This is followed by Bavin's Gulls on Cliveden Deep with landscaped hanging beech woods on the escarpment above which hosts Cliveden , a grandiose mansion run by a visitors' and public hire charity which

9760-403: 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 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

9882-734: 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 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

10004-414: The machinery. Multiple solutions have been suggested for this issue, including coating with a low-friction material, employing bristles, and others. The track system is built into the truss to guide the step chain, which continuously pulls the steps from the bottom platform and back to the top in an endless loop. One track guides the front wheels of the steps (called the step-wheel track) and another guides

10126-543: The matching cleats on each step (and resemble a comb). The comb plates, which bolt to the comb bearer (usually 4 or 5 depending on the width of the machine), help to minimize the gap between the stairs and landing, preventing objects or persons from becoming caught in it. The comb bearer, depending on what brand of the escalator will push back and/or up and activate limit switches in the event of an impact of something that jams through combs (typically stones, screws & popcorn) can be someone's shoe/item loose clothing. The truss

10248-413: The mid-1980s. The world's first practical spiral escalator—a Mitsubishi model—was installed in Osaka , Japan, in 1985. Helixator, an experimental helical escalator design that currently exists as a prototype scale model, could further reduce floor space demands. Its design has several innovations that allow a continuous helix; driven by a linear motor instead of a chain system, it spreads force evenly along

10370-489: The movement of the steps as a safety measure. This helps riders steady themselves, especially when stepping onto the moving stairs. Occasionally a handrail moves at a slightly different speed from the steps, causing it to "creep" slowly forward or backward relative to the steps; it is only slippage and normal wear that causes such losses of synchronicity, and is not by design. The direction of escalator movement (up or down) can be permanently set, controlled manually depending on

10492-656: 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

10614-528: The passage of fish. Some fish such as lampreys, trout and salmon go upstream to spawn. Measures such as 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

10736-687: The passenger to either side. Seeberger teamed with Otis in 1899, and together they produced the first commercial escalator. It won first prize at the 1900 Paris Exposition Universelle . Also on display at the Exposition were Reno's inclined elevator, a similar model by James M. Dodge and the Link Belt Machinery Co., and two different devices by the French manufacturers Hallé and Piat. Piat installed its "stepless" escalator in Harrods Knightsbridge store on Wednesday, November 16, 1898, though

10858-440: The predominant flow of the crowd, or controlled automatically. In some setups, the direction is controlled by whoever arrives first. Landing platforms are the two platforms (at the two ends) that house the curved sections of the tracks, as well as the gears and motors that drive the stairs. The top platform usually contains the motor assembly and the main drive gear, while the bottom holds the return gear. These sections also anchor

10980-528: The public had instead come to pronounce it / ˈ ɛ s k ə l eɪ t ɔːr / ( ess-kal- ATE -or ). "Escalator" was not a combination of other French or Greek words, and was never a derivative of " elevator " in the original sense, which means "one who raises up, a deliverer" in Latin. Similarly, the root word " scala " does not mean "a flight of steps", but is the singular form of the plural noun " scalae ", which can denote any of: "a flight of steps or stairs,

11102-430: The riser and the tread of each step is cleated (given a ribbed appearance) with comb-like protrusions that mesh with the comb plates on the top and bottom platforms and the succeeding steps in the chain. Seeberger escalators featured flat treads and smooth risers; other escalator models have cleated treads and smooth risers. The steps are linked by a continuous metal chain that forms a closed loop. The front and back edges of

11224-548: The shoe's material combined with the smaller size of children's feet makes this sort of accident especially common. Escalators sometimes include fire protection systems including automatic fire detection and suppression systems within the dust collection and engineer pit. To limit the danger caused by overheating, spaces that contain motors and gears typically include additional ventilation. Small, targeted clean agent automatic extinguishing systems are sometimes installed in these areas. Fire protection of an escalator floor opening

11346-469: 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 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

11468-501: The slider and consists of either steel cable or flat steel tape, providing the handrail with tensile strength and flexibility. The inner components, on top of the tension member, are made of chemically treated rubber designed to prevent the layers from separating. Finally, the outer layer—the part that passengers see—is the cover, typically a blend of synthetic polymers and rubber. Covers are designed to resist degradation from environmental conditions, mechanical wear and tear and vandalism. In

11590-538: The source of the word "escalator", and some degree of misinformation then proliferated. For reference, contradictory citations by seven separate individuals, including the Otis Elevator Company itself, are provided below. Seeberger trademarked the word "escalator" in 1900, to coincide with his device's debut at the Exposition universelle . According to his own account, in 1895, his legal counsel advised him to name his new invention, and he then set out to devise

11712-407: 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

11834-411: 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

11956-429: The steps each have two wheels, the rear of which are set further apart and fit into the trailer-wheel track while the front set have narrower axles and fit the step-wheel track. Jesse Reno also designed the first escalators installed in any underground subway system in the form of a helical escalator at Holloway Road tube station in London in 1906. The experimental device never saw public use and its remains are now in

12078-399: The steps into a shape resembling a staircase. At the top and bottom of the escalator, the two tracks converge so that the front and back wheels of the steps are almost in a straight line. This causes the stairs to lay in a flat sheetlike arrangement, one after another, so they can easily travel around the bend in the curved section of track. The tracks carry the steps down along the underside of

12200-413: 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

12322-488: 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,

12444-400: 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

12566-538: The truss until they reach the bottom landing, where they pass through another curved section of track before exiting the bottom landing. At this point, the tracks separate and the steps once again assume a staircase configuration. This cycle is repeated continually as the steps are pulled from bottom to top and back to the bottom again. The steps themselves are solid, one piece, die-cast aluminium or steel. Yellow demarcation lines are sometimes added to indicate their edges. In most escalator models manufactured after 1950, both

12688-700: The twenty-first century Schindler became the largest maker of escalators and second largest maker of elevators in the world, though their first escalator installation did not occur until 1936. In 1979, the company entered the United States market by purchasing the Haughton Elevator company. A decade later, Schindler assumed control of the North American escalator/elevator operations of Westinghouse, forming Schindler's American division . Notable examples of historic escalators still in operation include: Authors and historians have offered multiple interpretations of

12810-456: 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 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

12932-416: 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 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

13054-556: The wealthy and famous passed through the lock, some on their way to Cliveden . In 1899 an iron railing was placed round the lock to keep spectators at bay. In 1909 the Thames Conservancy purchased Ray Mill Island to provide for expansion of the lock, and it was rebuilt in 1912. Congestion at the lock was a serious problem before World War I , and a novel solution was employed to reduce it. A moving ramp, consisting of wooden slats with chocks to prevent rowing boats from rolling over,

13176-453: 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 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

13298-467: The word "escalator", the term was officially genericized, and it fell into the public domain . Design factors include innovative technology, physical requirements, location, traffic patterns, safety considerations, and aesthetics. Physical factors such as the distance to be spanned determine the length and pitch of the escalator, while factors such as the infrastructure's ability to provide support and power must be considered. How upward and downward traffic

13420-415: Was a miller and referred to the mill of Taplow. In 1773 a resident landowner complained of trespass in his woods by barge crews who "very much misbehaved themselves by their indecent conversation and horrid oaths and imprecations." Its prototype lock-keeper's house was built here in 1774. By 1780 the lock was reported as being in as bad a state as Marlow, and in 1795 Phillips Inland Navigation complained of

13542-456: 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

13664-422: 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 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

13786-416: 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,

13908-512: Was approved, George A. Wheeler patented his ideas for a more recognizable moving staircase, though it was never built. Wheeler's patents were bought by Charles Seeberger ; some features of Wheeler's designs were incorporated in Seeberger's prototype that was built by the Otis Elevator Company in 1899. Reno , a graduate of Lehigh University , produced the first working escalator (called the "inclined elevator") and installed it alongside

14030-505: Was awarded £100 by the Commission in June 1829. The new lock was known as Ray Mill pound after Ray Mill Island next to it. The lock cut created Boulter's Island . This part of the river became popular for boating parties in the late 19th century and early 20th century, as portrayed in a painting by Edward John Gregory . The lock was a popular place to visit on the Sunday after Royal Ascot when

14152-434: Was constructed to bypass the lock. The ramp was similar to an escalator , and small boats simply rowed towards it, and were carried up to the higher level while the occupants remained seated in their boat. The boat lift opened in 1909, and was powered by an electric motor. The date of its demise is uncertain, but its location on Ray Mill island can still be visited. The salmon ladder opened at Boulters Weir on 19 May 2000 by

14274-437: Was either manual or hydraulic. In 1889, Leamon Souder successfully patented the "stairway", an analogous device that featured a "series of steps and links jointed to each other". No model was ever built. This was the first of at least four escalator-style patents issued to Souder, including two for spiral designs. On March 15, 1892, Jesse W. Reno patented the "Endless Conveyor or Elevator." A few months after Reno's patent

14396-473: Was in the 20th century a forum for a prominent set of individuals and scene of the John Profumo affair . The river then curves round to Formosa Island and the other islands where Cookham Lock has been built. The Thames Path follows the western (Maidenhead) bank upstream along Cliveden Reach until it cuts into Cookham village, missing Cookham Lock. The path rejoins the Thames near Cookham church. There

14518-412: 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 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

14640-434: Was originally a towpath ferry (My Lady ferry or Lower Cliveden ferry) crossing to Cliveden and an Upper Cliveden ferry crossing back to Cookham lock island. The weir at Boulter's Lock is a popular kayaking site. A canoe /kayak flume is installed during each summer to add to a permanent fixed ramp in front of the third of the weir's six gates. One of the best known works of the artist Edward John Gregory (1850–1909)

14762-451: 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 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

14884-588: 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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