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{{short description|Moving staircase}}
{{For|the album by Sam Gopal|Escalator (album)}} {{For|the album by Sam Gopal|Escalator (album)}}
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An '''escalator''' is a moving staircase – a conveyor transport device for carrying people between floors of a building. The device consists of a ]-driven chain of individual, linked steps that move up or down on tracks, allowing the step treads to remain horizontal.

Escalators are used around the world to move ] traffic in places where ]s would be impractical. Principal areas of usage include ]s, ]s, ]s, ], ]s, ]s, ]s, ]s, train stations (subways) and public buildings.

Escalators have the capacity to move large numbers of people, and they can be placed in the same physical space as one might install a staircase. They have no waiting interval (except during very heavy traffic), they can be used to guide people toward main exits or special exhibits, and they may be weatherproofed for outdoor use. A non-functioning escalator can function as a normal staircase, whereas many other conveyances become useless when they break down.

==Design, components, and operation==

===Operation and layout===
Escalators are like ]s, are often powered by constant-speed ] motors{{Citation needed|reason=How do you know this? Why wouldn't DC motors or VFD motors be used as well, especially when their speed is controllable in a much easier manner?|date=August 2011}} and move at approximately {{convert|1|–|2|ft|1}} per second. The typical angle of inclination of an escalator to the horizontal floor level is 30 degrees with a standard rise{{clarify|date=May 2013}} up to about {{convert|60|ft}}. Modern escalators have single-piece ] or ] steps that move on a system of tracks in a continuous loop.

]
]
]

Escalators have three typical configuration options: ''parallel'' (up and down escalators side by side or separated by a distance, seen often in metro stations and multilevel motion picture theaters), ''crisscross'' (minimizes space requirements by "stacking" escalators that go in one direction, frequently used in department stores or shopping centers), and ''multiple parallel'' (two or more escalators together that travel in one direction next to one or two escalators in the same bank that travel in the other direction).<ref>Strakosch, George R. ''Vertical Transportation, Elevators and Escalators'', New York: John Wiley & Sons, 1983.</ref>

As a safety measure, escalators are required to have moving handrails that keep pace with the movement of the steps. This helps riders steady themselves, especially when stepping onto the moving stairs. Occasionally, a handrail will move at a slightly different speed from the steps, causing it to "creep" slowly forward or backward relative to the steps. The loss of synchronization between handrail and step speed can result from slippage and wear.<ref>{{cite web | title = Mitsubishi Electric Escalators Series Z | publisher = Mitsubishi Elevator Asia Co., Ltd. | url = http://www.mitsubishielevator.com/images/uploads/documents/pdf/escalators/linear/Z_Type_Escalator_for_USA.pdf | format = pdf | accessdate = 2014-04-17}}</ref>

The direction of escalator movement (up or down) can be permanently set, or be controlled by personnel according to the predominant flow of the crowd, or be controlled automatically. In some setups, direction is controlled automatically by whoever arrives first, whether at the bottom or at the top (the system is programmed so that the direction is not reversed while a passenger is on the escalator).

===Design and layout considerations===
A number of factors affect escalator design, including physical requirements, location, traffic patterns, safety considerations, and aesthetic preferences. Foremost, physical factors like the vertical and horizontal distance to be spanned must be considered. These factors will determine the length and pitch of the escalator. The building infrastructure must be able to support the heavy components. The escalator should be located where it can be easily seen by the general public. In department stores, customers should be able to view the merchandise easily. Furthermore, up and down escalator traffic should be physically separated and should not lead into confined spaces.

Traffic patterns must also be anticipated. In some buildings, the objective is simply to move people from one floor to another, but in others there may be a more specific requirement, such as funneling visitors towards a main exit or exhibit. The escalators must be designed to carry the required number of passengers. For example, a single-width escalator traveling at about {{convert|1.5|ft|1}} per second can move about 2000 people per hour. The carrying capacity of an escalator system must match the expected peak traffic demand, presuming that passengers ride single file. This is crucial if there are sudden increases in the number of riders. For example, escalators at stations must be designed to cater for the peak traffic flow discharged from a train, without causing excessive bunching at the escalator entrance.

In this regard, escalators help in controlling the flow of people. For example, an escalator to an exit effectively discourages most people from using it as an entrance{{clarify|date=May 2013}}, and may reduce security concerns. Similarly, escalators often are used as the exit from ]. Such an egress point would still generally be staffed to prevent its use as an entrance during times of light pedestrian traffic.

It is preferred that staircases be located adjacent to the escalator if the escalator is the primary means of transport between floors.{{citation needed|date=November 2013}} It may also be necessary to provide an elevator lift near the escalator for wheelchairs and disabled people. Finally, consideration should be given to the aesthetics of the escalator.

===Model sizes and other specifications===
{| class="wikitable"
|+ Escalator step widths and energy usage
|-
! Size
! Width (between balustrade panels)
! Single-step capacity
! Applications
! Power consumption
|-
! Very very small
| {{convert|400|mm|in|abbr=on}}
| One passenger, with feet together
| A rare historic design found mostly in older department stores
| {{convert|3.7|kW|hp|0|abbr=on}}
|-
! Small
| {{convert|600|mm|in|abbr=on}}
| One passenger
| Low-volume sites, uppermost levels of department stores, when space is limited
| {{convert|3.7|kW|hp|0|abbr=on}}
|-
! Medium
| {{convert|800|mm|in|abbr=on}}
| One passenger + one package or one piece of luggage
| Shopping malls, department stores, smaller airports
| {{convert|7.5|kW|hp|0|abbr=on}}
|-
! Large
| {{convert|1000|mm|in|abbr=on}}
| Two passengers – one may walk past another
| Mainstay of metro systems, larger airports, train stations, some retail usage and in sky train
| {{convert|7.5|kW|hp|0|abbr=on}}
|}

===Components===
; Landing platforms: These two platforms house the curved sections of the tracks, as well as the gears and motors that drive the stairs. The top platform contains the motor assembly and the main drive gear, while the bottom holds the step return idler sprockets. These sections also anchor the ends of the escalator truss. In addition, the platforms contain a floor plate and a combplate. The floor plate provides a place for the passengers to stand before they step onto the moving stairs. This plate is flush with the finished floor and is either hinged or removable to allow easy access to the machinery below. The combplate is the piece between the stationary floor plate and the moving step. It is so named because its edge has a series of cleats that resemble the teeth of a comb. These teeth mesh with matching cleats on the edges of the steps. This design is necessary to minimize the gap between the stair and the landing, which helps prevent objects from getting caught in the gap.

; Truss: The truss is a hollow metal structure that bridges the lower and upper landings. It is composed of two side sections joined together 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. The truss carries all the straight track sections connecting the upper and lower sections.

; Tracks: 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. There are actually two tracks: one for the front wheels of the steps (called the step-wheel track) and one for 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 combplate. 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 bends 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 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.

; Steps: The steps themselves are solid, one piece, die-cast aluminum or steel. Yellow demarcation lines may be added to clearly indicate their edges. In most escalator models manufactured after 1950, both the riser and the tread of each step is cleated (given a ribbed appearance) with comblike protrusions that mesh with the combplates on the top and bottom platforms and the succeeding steps in the chain. Seeberger- or "step-type" escalators (see below) 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 the steps are each connected to two wheels. The rear wheels are set further apart to fit into the back track and the front wheels have shorter axles to fit into the narrower front track. As described above, the position of the tracks controls the orientation of the steps.

; Handrail: The handrail provides a convenient handhold for passengers while they are riding the escalator. In an escalator, the handrail is pulled along its track by a chain that is connected to the main drive gear by a series of pulleys. It is constructed of four distinct sections. At the center of the handrail is a "slider", also known as a "glider ply", which is a layer of a cotton or synthetic textile. The purpose of the slider layer is to allow the handrail to move smoothly along its track. The next layer, known as the "]", consists of either steel cable or flat steel tape, and provides the handrail with tensile strength and flexibility. On top of tension member are the inner construction components, which are made of chemically treated rubber designed to prevent the layers from separating. Finally, the outer layer—the only part that passengers actually see—is the cover, which is a blend of synthetic polymers and rubber. This cover is designed to resist degradation from environmental conditions, mechanical wear and tear, and human vandalism.

:In the factory, handrails are constructed by feeding rubber through a computer-controlled 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 skilled workers before being fed into the presses, where they are fused together.

:In the mid-twentieth century, some handrail designs consisted of a rubber bellows, with rings of smooth metal cladding called "bracelets" placed between each coil. This gave the handrail a rigid yet flexible feel. Additionally, each bellows section was no more than a few feet 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 conventional fabric-and-rubber railings.

{{gallery |align=center |lines=5 | title=Escalator components
|File:Escalator Repair.jpg|An escalator being repaired at Town Hall station in Sydney, Australia
|File:Eskalator Flora.jpg|A "freestanding" escalator reveals its inner components through the transparent truss.
|File:Praha, Nové Město, Stanice metra I. P. Pavlova, rekonstrukce eskalátorů.JPG|Escalator truss connects to the landing platform (lower left). Also visible: exposed drive gears (center) for steps and handrail drive (left)
|File:Escalator mechanism 03.jpg|View of escalator steps on continuous chain
|File:Handrail.jpg|An escalator equipped with a "bellows" handrail. The bracelets are colored grey, with occasional strings of black ones to appear as moving spacers.
}} }}
]]]
] in ]]]
]
]'' statue in ], Brazil]]


An '''escalator''' is a moving ] which carries people between floors of a building or structure. It consists of a ]-driven chain of individually linked steps on a track which cycle on a pair of tracks which keep the step tread horizontal.
==Safety==
]
Safety is also major concern in escalator design. In ], where women wear ]s, there are heavy chances of getting the ''pallu'' entangled in the escalator.<ref></ref> As a result, a special ''sari guard'' is built into most escalators.


Escalators are often used around the world in places where ]s would be impractical, or they can be used in conjunction with them. Principal areas of usage include ]s, ]s, ]s, ] (railway/railroad stations), ]s, ]s, ]s, ]s and public buildings.
There is a risk of foot injuries for children wearing footwear such as ] and ] that might get caught in escalator mechanisms.<ref name="ABC-Snow">Snow, Kate (October 5, 2006). ''ABC News.''. Retrieved April 19, 2007.</ref><ref name="ABC-AP">AP (April 21, 2008). . ''ABC Business News''. Retrieved November 5, 2009.</ref> This was due to the softness of the shoe's material combined with the smaller size of children's feet.<ref name="WMC-TV"> ''WMC-TV Memphis Tennessee.'' September 21, 2006. Retrieved April 19, 2007.</ref>


Escalators have 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.
Fire protection of an escalator may be provided by adding automatic fire detection and suppression systems inside the dust collection and engineer pit, in addition to any water sprinkler system installed in the ceiling. To limit the danger caused by overheating, ventilation for the spaces that contain the motors and gears must be provided, and small targeted clean agent automatic extinguishing systems can be installed in these areas. Fire protection of an escalator floor opening may be provided by adding automatic sprinklers or fireproof shutters to the opening, or by installing the escalator in an enclosed fire-protected hall.


== History ==
===Accidents and litigation===


=== Inventors and manufacturers ===
], widely known as the MBK Center, in ]. Such layouts are used to minimize structural space requirements by "stacking" escalators that go in one direction.]]
]]]


], a patent attorney from ], 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 was either manual or hydraulic.<ref>{{patent|US|25076|Ames, N. Revolving Stairs August 9, 1859}}</ref>
====Lessons of the King’s Cross fire====


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.<ref>{{patent|US|406314|Souder, Leamon. Stairway July 2, 1889}}</ref> This was the first of at least four escalator-style patents issued to Souder, including two for spiral designs.<ref>{{Patent|US|723325}} {{Patent|US|792623}}</ref>
]
The ] of 1987 illustrated the demanding nature of escalator upkeep and the devices’ propensity to collect “fluff” when not properly maintained.<ref>Moodie, K. “The King’s Cross Fire: Damage Assessment and Overview of the Technical Investigation.” ‘’Fire Safety Journal’’, Vol. 18, 1992: 13–33.</ref>


On March 15, 1892, ] patented the "Endless Conveyor or Elevator."<ref>{{patent|us|470918|Reno, Jesse W. Endless Conveyer or Elevator March 1892}}</ref> A few months after Reno's patent was approved, ] patented his ideas for a more recognizable moving staircase, though it was never built.<ref>{{patent|us|479864|Wheeler, G. A., "Elevator", August 2, 1892}}</ref> Wheeler's patents were bought by ]; some features of Wheeler's designs were incorporated in Seeberger's prototype that was built by the ] in 1899. ], a graduate of ], produced the first working escalator (called the "inclined elevator") and installed it alongside the Old Iron Pier at ], ] in 1896.<ref>This is accepted as the world's first operable escalator installation. Dates for the Harrods Piat escalator installation are inconsistent.{{citation needed|date=July 2017}}</ref> 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 ]. Reno eventually joined forces with Otis and retired once he had sold his patents. Some Reno-type escalators were still being used in the ] until construction for the ] ({{circa|1991}}) precipitated their removal. The ] 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.<ref>Topel, Michael. "Ancient Escalator Was a Link to History," ''The Patriot-Ledger'', April 3, 1995. See also {{cite book|url={{google books |plainurl=y |id=WuBSAAAAMAAJ|page=79}}|title=Up, down, across: elevators, escalators and moving sidewalks|last=King|first=John|date=September 2003|publisher=Merrell|pages=79–89|chapter=A Matter of Perception: Escalators, Moving Walks, and the Motion of Society|editor-first1=Alisa|editor-last1=Goetz}}</ref>
In the official inquiry that followed, the ], it was determined that the fire started slowly, smouldered virtually undetected for a time, then exploded into the ticket hall above in a previously-unrecognised phenomenon known as the “].” In the escalators’ undercarriage, approximately {{convert|8800|kg}} of accumulated ] acted as a ] 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 the impact of the calamity.<ref>”Building Design Editorial: the King’s Cross Inquiry,” ‘’Building Design’’, November 19, 1988: 9</ref>


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 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 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 ]. 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.
As a result of 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 nonsmoking; eventually the whole system became a smoke-free zone.


Piat installed its "stepless" escalator in ] ] store on Wednesday, November 16, 1898, though 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."<ref>{{cite book|url={{google books |plainurl=y |id=oQm8AAAAIAAJ|page=50}}|title=The department store: a social history|last=Lancaster|first=William|publisher=Leicester University Press|year=1995|isbn=978-0-7185-1374-0|pages=50}}</ref> 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.<ref>"The First Moving Staircase in England," ''The Drapers' Record'', November 19, 1898: 465.</ref>
====Litigation====
In the 1930s, at least one suit was filed against a department store, alleging that its escalators posed an ], responsible for a child’s injury.<ref>”Negligence: Escalator Not an Attractive Nuisance,” ''Michigan Law Review'', Vol. 38, No. 2 (Dec. 1939): 265 – 267.</ref>


Hocquardt received European patent rights for 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.
===Legislation and escalators===


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." ]-based Peelle Company called their models the Motorstair, while ] called their model an Electric Stairway. The ]-based Haughton Elevator company referred to their product as simply Moving Stairs. The Otis trademark is no longer in effect.
====United States====
Despite their considerable scope, two ], the ] and the ], did not directly affect escalators or their public installations. Since Section 504 of the Rehabilitation Act included public transportation systems, for a few years, the ] considered designs to retrofit existing escalators for wheelchair access. Nonetheless, ] 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 retention in public structures.<ref>”ADA Requirements, November 23, 1998,” U.S. Department of Justice, Civil Rights Division, 1998: 3.</ref>


] and ] introduced their first escalator models several decades after the Otis Elevator Co., but grew to dominate the field over time. Today, ] and ] are Otis's primary rivals. Kone expanded internationally by acquisition in the 1970s, buying out Swedish elevator manufacturer ], 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 ] company, then took control of Germany's ].<ref>{{Cite web |title=Birth of a global machine |url=https://www.kone.com/en/company/history/ |website=Kone}}</ref>
===Codes and regulation===
In the United States and Canada, new escalators must abide by ] ] standards, and old/historic escalators must conform to the safety guidelines of ] ]. In Europe, the escalator safety code is ].


In 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.<ref>{{cite web |title=A fascinating story… |url=https://group.schindler.com/en/company/history.html#:~:text=1936%3A%20The%20first%20escalator%20installation,was%20completed%20in%20Basel%2C%20Switzerland. |website=Schindler}}</ref> In 1979, the company entered the United States market by purchasing the Haughton Elevator company.<ref>{{Cite web |title=Haughton & Schindler Haughton |url=https://sites.google.com/view/naelevatorguide/elevators/haughton |website=North American Elevator Guide}}</ref> A decade later, Schindler assumed control of the North American escalator/elevator operations of Westinghouse, forming ].<ref>{{Cite web |title=Schindler restructures U.S. operations |url=https://www.upi.com/Archives/1989/05/23/Schindler-restructures-US-operations/1863611899200/ |website=United Press International}}</ref>
]


=== Extant historic escalator models ===
==History==
] ] in New York City holds some well-known historic escalators. The model shown here, retrofitted with metal steps in the 1990s, is among the oldest of the store's 40 escalators. Otis "L-type" escalators with distinctive wood treads (not shown) have operated in the store since 1927.]]
], Australia]]


Notable examples of historic escalators still in operation include:
===Inventors and manufacturers===


* St Anna Pedestrian Tunnel underneath the ] river in ], Belgium, opened 1933.
====Nathan Ames====
* ]'s bicycle/pedestrian tunnel, adjacent to its car tunnel in ], The Netherlands, opened 1942.
]]]
* ], ], England, constructed 1951.<ref>These escalators, manufactured by Waygood Otis, were "believed to be the longest link single lift escalators in the world", at the time of installation. Presumably the first escalators in Britain designed specifically for cyclists, they were also the longest in the United Kingdom. At most, they may be the longest extant wooden escalators in the world, though they are no longer in working order.</ref><ref>{{cite web|url=http://www.tynetunnel.info/wps/wcm/connect/Tunnel/Pedestrian+and+Cycle+Tunnels/History/|title=Tyne Tunnel Construction History|access-date=2008-11-10|url-status=dead|archive-url=https://web.archive.org/web/20080821145432/http://www.tynetunnel.info/wps/wcm/connect/Tunnel/Pedestrian+and+Cycle+Tunnels/History/|archive-date=August 21, 2008|df=mdy}}</ref>
], a patent solicitor from ], is credited with patenting the first "escalator" in 1859, despite the fact that 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), though the mechanization was suggested to run either by manual or hydraulic power.<ref>Ames, N. "Revolving Stairs," U. S. Patent 25076. August 9, 1859. Available: http://uspto.gov</ref>
* ] department store upwards escalators, ], U.S., opened 1920s.<ref>Otis L-type units with wood treads and replacement metal treads, only in escalators heading upwards from the first to the seventh stories.</ref><ref>{{cite news|url=https://www.nytimes.com/2015/11/26/nyregion/macys-historic-wooden-escalators-survive-renovation.html|title=Latest Miracle on 34th Street: Macy's Keeps Wooden Escalators|first=David W.|last=Dunlap|date=2015-11-25|access-date=2017-07-06|work=]}}</ref>


====Leamon Souder==== === Etymology ===
In 1889, ] successfully patented the "stairway", an escalator-type device that featured a "series of steps and links jointed to each other". No model was ever built.<ref>Souder, Leamon. "Stairway," U. S. Patent 406314. July 2, 1889. Available: http://uspto.gov</ref> This was the first of at least four escalator-style patents issued to Souder, including two for spiral designs (U. S. Patent Nos. 723,325 and 792,623).


Authors and historians have offered multiple interpretations of 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.<ref>See: Barrow, Dennis. "Seeberg.doc", Internal document, Otis Elevator Co., Farmington, CT: United Technologies; . June 2004. Oxford University Press, {{cite web|title=Otis Firsts: Escalators in the Gaslight Era|url=http://www.otis.com/otis150/section/1%2C2344%2CARC3125_CLI1_RES1_SEC2%2C00%2Ehtml |publisher=Otis Elevator Co.|access-date=July 27, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070811021933/http://www.otis.com/otis150/section/1,2344,ARC3125_CLI1_RES1_SEC2,00.html |archive-date=August 11, 2007 }}; "Subject: History of the Escalator" (unnumbered sales circular letter). Internal document, Otis Elevator Co., Farmington, CT: United Technologies, October 16, 1962; , ''Human Interest'', Online. The Museum for the Preservation of Elevating History Worthington, Jr., William. "Early Risers", ''American Heritage of Invention & Technology'', Vol. 4, No. 3 (Winter 1989): 42; and Wosk, Julie. "Perspectives on the Escalator in Photography and Art", in ''Up Down Across: Elevators, Escalators and Moving Sidewalks.'' (Alisa Goetz, ed.) London: Merrell, 2003.</ref>
====Jesse Wilford Reno, George A. Wheeler, and Charles Seeberger====
On March 15, 1892, ] patented the "Endless Conveyor or Elevator."<ref>Reno, Jesse W. "Endless Conveyer or Elevator," U. S. Patent 47091815. March 1892. Available: http://uspto.gov</ref> A few months after Reno's patent was approved, ] patented his ideas for a more recognizable moving staircase, though it was never built.<ref>Wheeler, G. A., "Elevator," U. S. Patent 479864, August 2, 1892. Available: http://uspto.gov.</ref> Wheeler’s patents were bought by ]; some features of Wheeler’s designs were incorporated in Seeberger’s prototype built by the ] in 1899.


Seeberger ]ed 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 a title for it. As evidenced in Seeberger's handwritten documents, the inventor consulted "a ] lexicon" and "adopted as the root of the new word, 'Scala'; as a prefix, 'E' and as a suffix, 'Tor.'"<ref>De Fazio, Diane H. ''Like Blood to the Veins: Escalators, their History, and the Making of the Modern World'' (Master's Thesis, Columbia University Graduate School of Architecture, Planning, and Preservation), 2007: 58&nbsp;– 61.</ref> His own rough translation of the word thus created was "means of traversing from", and he intended for the word to be pronounced {{IPAc-en|ɛ|s|'|k|æ|l|ə|t|ɔːr}} ({{respell|ess|KAL|ə|tor}}). By 1906, Seeberger noted that the public had instead come to pronounce it {{IPAc-en|'|ɛ|s|k|ə|l|eɪ|t|ɔːr}} ({{respell|ess|kal|ATE|or}}).<ref>De Fazio, 60.</ref>
], a graduate of ], produced the first working escalator (he actually called it the "inclined elevator") and installed it alongside the Old Iron Pier at ], ] in 1896.<ref>On record and in practice, this is accepted as the world's first operable escalator installation. Dates for the Harrods Piat escalator installation are inconsistent.</ref> 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° incline. A few months later, the same prototype was used for a month-long trial period on the Manhattan side of the ]. Reno eventually joined forces with Otis, and retired once his patents were purchased outright. Some Reno-type escalators were still being used in the ] until construction for the ] precipitated their removal. The ] 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.<ref>Topel, Michael. "Ancient Escalator Was a Link to History", ''The Patriot-Ledger'', April 3, 1995. See also King, John. "A Matter of Perception: Escalators, Moving Walks, and the Motion of Society", in ''Up Down Across: Elevators, Escalators and Moving Sidewalks''. (Alisa Goetz, ed.) London: Merrell, 2003: 79–89.</ref>


"Escalator" was not a combination of other French or Greek words, and was never a derivative of "]" in the original sense, which means "one who raises up, a deliverer" in Latin.<ref name="Lewis">{{cite book|url={{google books |plainurl=y |id=CQ6bMwEACAAJ}}|title=A Latin Dictionary: Founded on Andrews' Edition of Freund's Latin Dictionary|last2=Lewis|first2=Charlton Thomas|last3=Freund|first3=William|last4=Short|first4=Charles|publisher=Clarendon Press|year=1966|first1=Ethan Allen|last1=Andrews}}</ref> 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, a staircase; a ladder, a scaling-ladder."<ref name="Lewis" />
Around May 1895, Charles Seeberger began drawings on a form of escalator similar to those patented by Wheeler in 1892. This device actually consisted of flat, moving stairs, not unlike 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 the passenger to either side. Seeberger teamed with Otis in 1899, and together they produced the first commercial escalator which won the first prize at the Paris ] in France. Also on display at the ''Exposition'' were Reno's inclined elevator, a similar model by ] and the ], and two different devices by French manufacturers ] and ].


The alleged intended ] 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 the character of trade-mark."<ref>Seeberger, Charles D. "Trade-mark for Passenger-Elevators." ''U. S. Trade-mark No. 34724.'' May 29, 1900. Available: http://uspto.gov</ref> Otis Elevator Co. advertisements so frequently capitalized all of the letters in the word.
====Early European manufacturers: Hallé, Hocquardt, and Piat====
Piat installed its "stepless" escalator in ] Knightsbridge store on Wednesday, November 16, 1898, though 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."<ref>Lancaster, Bill. ''The Department Store: a Social History''. London: Leicester University Press, 1995: 50.</ref> 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.<ref>"The First Moving Staircase in England," ''The Drapers' Record'', November 19, 1898: 465.</ref>


{{See also|Genericized trademark}}
] received European patent rights for 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 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.<ref>Folsom, Ralph H. and Larry L. Teply. "Trademarked Generic Words", ''The Yale Law Journal'', Vol. 89, No. 7 (Jun. 1980): 1323–1359.</ref> Confirming the contention of 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 been issued to them and... in their advertising matter."<ref>''Haughton Elevator Co. v. Seeberger''85 U. S. P. Q. (BNA) 80–81 (Dec. Comm. Pat. 1950).</ref> All trademark protections were removed from the word "escalator", the term was officially genericized, and it fell into the ].
====Major competitors and product nomenclature====
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.” ]-based ] Company called their models the '''''Motorstair''''', and ] called their model an '''''Electric Stairway'''''. The ]-based ] company referred to their product as simply '''''Moving Stairs'''''.


== Design ==
====Manufacturing mergers and buyouts: the playing field narrows====
]
] and ] introduced their first escalator models several decades after the Otis Elevator Co., but grew to dominance in the field over time. Today, they, ], and ] are Otis' primary rivals.
]
]


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 is separated and load/unload areas are other important considerations.
Schindler now stands as the largest maker of escalators and second largest maker of elevators in the world, though their first escalator installation did not occur until 1936.<ref>Dorsch, Jeff. "Schindler Holding Ltd.," ''Hoover’s Business Database'', http://www.hoovers.com, Mar. 2007.</ref> In 1979, the company entered the United States market by purchasing Haughton Elevator; nine years later, Schindler assumed control of the North American escalator/elevator operations of ].


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, a single-width escalator traveling at about {{convert|1+1/2|ft/s|m/s|1|order=flip}} 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 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.
Kone expanded internationally by acquisition in the 1970s, buying out Swedish elevator manufacturer ], and purchasing other minor French, German, and Austrian elevator makers before assuming control of Westinghouse’s European elevator business. As the last "big four" manufacturers held on to the escalator market, KONE first acquired ], then took control of Germany’s ] ''Rolltreppen''.


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.
===Model development and design types===


Escalators typically rise at an angle of 30 or 35 degrees from the ground.<ref>{{Cite book|url={{google books |plainurl=y |id=7TVSAAAAMAAJ}}|title=Railway Stations: Planning, Design and Management|last=Ross|first=Julian|date=2000|publisher=Architectural Press|isbn=9780750643764|language=en}}</ref> They move at {{convert|1|–|3|ft/s|m/s|1|order=flip}}, like ]s, and may traverse vertical distances in excess of {{convert|60|ft|m|order=flip}}. Most modern escalators have single-piece ] or ] steps that move on a system of tracks in a continuous loop.
====Cleat-type escalators====
Jesse Reno's escalators did not resemble modern escalators too closely. Passenger feet tilted upward at an angle, and the treads consisted of cleated metal (initially) or wood (later models). Reno worked on his own for several years, gaining success with installations from ] to ]. Similar units of the day by other manufacturers resembled conveyor belts more than moving staircases. For a time, Otis Elevator sold Reno's escalators as their own cleat-type escalators.


Different types of escalator planning include:
====Step-type escalators====
Seeberger's model, bought by Otis, clearly became the first step-type escalator, named for its visual likeness to a regular staircase. The company later combined the best aspects of both inventions (guiding slats and flat steps) and in 1921 produced an escalator similar to the type used today, calling it an L-type escalator. It was succeeded by the M-type, the O-type, and current models by Otis such as the NCE-type escalator.


* ''Parallel'' (up and down escalators adjacent or nearby, often seen in perpendicular areas, ]s and multilevel ]s);
====Spiral/helical escalators====
* ''Multiple parallel'' (banks of more than one escalator going in the same direction parallel to banks going the other direction);
], Hong Kong]]
* ''Crisscross'' (escalators going in one direction "stacked" with escalators going the opposite direction oriented adjacent but perpendicular, frequently used in ] or ]).<ref>{{cite book|url={{google books |plainurl=y |id=J-BSAAAAMAAJ}}|title=Vertical transportation: elevators and escalators|last=Strakosch|first=George R.|publisher=Wiley|year=1983|isbn=978-0-471-86733-3}}</ref>


Most countries require escalators to have moving handrails that keep pace with 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.<ref>{{cite web | title = Mitsubishi Electric Escalators Series Z | publisher = Mitsubishi Elevator Asia Co., Ltd. | url = http://www.mitsubishielevator.com/images/uploads/documents/pdf/escalators/linear/Z_Type_Escalator_for_USA.pdf | access-date = 2014-04-17}}</ref>
], in addition to being known for the first practical escalator in public use, also designed the first escalators installed in any underground subway system in the form of a spiral (actually a ]) escalator at ] in London in 1906. The experimental device never saw public use, and was forgotten for several decades. The remains of this are now in the London Transport Museum's depot in Acton.<ref>{{dead link|date=April 2013}} London's Transport Museum Photographic Collection, "1906 Escalator Operated on Opening Day of Great Northern Picadilly and Brompton Railway, December 15, 1906."</ref>


The direction of escalator movement (up or down) can be permanently set, controlled manually depending on the predominant flow of the crowd, or controlled automatically. In some setups, the direction is controlled by whoever arrives first.{{citation needed|date=July 2017}}
Also the first fully operational spiral escalator, Reno’s design was nonetheless only one in a series of several similar proposed contraptions. ] patented two helical designs (see above), ] drafted helical stairway plans in 1905, ] devised at least two different helical units between 1906 and 1911 (including an unrealized arrangement for the London Underground), and ] obtained West German, Japanese, and United States patents for his version of a spiral escalator by 1973. When interviewed for the '']'' that year, Luna was in the process of soliciting major firms for acquisition of his patents and company, but statistics are unclear on the outcome of his endeavors in that regard.<ref>Hillinger, Charles. "Spiral Escalator May Be his Wheel of Fortune", ''Los Angeles Times,'' November 11, 1973: 3.</ref>


=== Components ===
The ] was most successful in its development of spiral/helical escalators, and has sold them exclusively since the mid-1980s. The world's first practical spiral escalator—a Mitsubishi model—was installed in ], Japan, in 1985.<ref>{{cite web|url=http://www.mitsubishielectric.com/elevator/innovations/spiral_escalators.html |title=Elevators & Escalators - MITSUBISHI ELECTRIC |publisher=mitsubishielectric.com |date= |accessdate=September 18, 2012}}</ref>
{{gallery|align=center|title=Escalator components
|file:Escalator Repair.jpg|An escalator being repaired at Town Hall station in Sydney, Australia
|file:Eskalator Flora.jpg|A "freestanding" escalator reveals its inner components through the transparent truss.
|file:Praha, Nové Město, Stanice metra I. P. Pavlova, rekonstrukce eskalátorů.JPG|Escalator truss connects to the landing platform (lower left). Also visible: exposed drive gears (center) for steps and handrail drive (left).
|file:JacksonSquareEscalatorMotor.jpg|View of an escalator's motor
|file:EscalatorWithoutSteps.jpg|An escalator with its steps removed
|file:Handrail.jpg|An escalator equipped with a "bellows" handrail. The bracelets are colored grey, with occasional strings of black ones to appear as moving spacers, etc.
}}


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 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 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.
In use, a major planning advantage presented by spiral/helical escalators is that they take up much less horizontal floor space than traditional units, which frequently house large machine rooms underneath the truss.


The truss 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.
Helixator, an experimental spiral/helical escalator design which currently exists as a prototype scale model, could further reduce the floor space. The design has several innovations that offer the possibility of a continuous helix. Driven by a linear motor instead of a chain system, the Helixator spreads the force evenly along the escalator path, avoiding excessive force on the top chain links and removing geometry, length and height limits.<ref>Stephen Harris. . The Engineer. December 23, 2010</ref>


The balustrade is composed of handrails, balustrade panels, and skirt panels.<ref name=":0">Tehrani, C. M. (2001). ''U.S. Patent No. 6,257,390''. Washington, DC: U.S. Patent and Trademark Office.</ref>
====Freeform escalators====


The handrail provides 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 "]" lies on 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{{mdash}}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 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 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, ], or glass, the balustrade panel supports the handrails of the escalator. It also provides additional protection for 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 the machinery. Multiple solutions have been suggested for this issue, including coating with a low-friction material, employing bristles, and others.<ref name=":0" />
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 uselessly underneath the in-use steps: rather, they provide active steps for travel in the opposite direction.<ref>http://www.city.ac.uk/news/2010/sep/city-university-london-unveils-worlds-first-freeform-curved-escalator</ref>
]


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 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 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 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.
==Etymology==
Several authors and historians have contributed their own differing interpretations of the source of the word “escalator”, and some degree of misinformation has heretofore proliferated on the ]. For reference, contradictory citations by seven separate individuals, including the Otis Elevator Company itself, are provided below.<ref>See: Barrow, Dennis. "Seeberg.doc", Internal document, Otis Elevator Co., Farmington, CT: United Technologies; "escalator, ''noun''." ''OED Online''. June 2004. Oxford University Press, available: http://dictionary.oed.com/cgi/entry/50077810; "Otis Firsts: Escalators in the Gaslight Era", Otis Elevator Co., available: <{{dead link|date=April 2013}}>; "Subject: History of the Escalator" (unnumbered sales circular letter). Internal document, Otis Elevator Co., Farmington, CT: United Technologies, October 16, 1962; "The Word ‘Escalator’", ''Human Interest'', Online. The Museum for the Preservation of Elevating History, available: http://www.theelevatormuseum.org/h/h-1.htm; Worthington, Jr., William. "Early Risers", ''American Heritage of Invention & Technology'', Vol. 4, No. 3 (Winter 1989): 42; and Wosk, Julie. "Perspectives on the Escalator in Photography and Art", in ''Up Down Across: Elevators, Escalators and Moving Sidewalks.'' (Alisa Goetz, ed.) London: Merrell, 2003.</ref>


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 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 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.
===Name development and original intentions===
] ] 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 a title for it on his own. As evidenced in Seeberger's own handwritten documents, archived at the ] headquarters in ], the inventor consulted "a ] lexicon" and "adopted as the root of the new word, 'Scala'; as a prefix, 'E' and as a suffix, 'Tor.'"<ref>De Fazio, Diane H. ''Like Blood to the Veins: Escalators, their History, and the Making of the Modern World'' (Master's Thesis, Columbia University Graduate School of Architecture, Planning, and Preservation), 2007: 58 – 61.</ref> His own rough translation of the word thus created was "means of traversing from", and he intended for the word to be pronounced, "es‧ʹkæl‧ə‧tər" (es-'''CAL'''-a-tor).<ref>De Fazio, 60. Seeberger noted that the public had come to call his invention the "escə‧lāʹ‧tər" (es-ca-'''LĀ'''-tor) by 1906.</ref>


=== Alternative designs ===
"Escalator" was not a combination of other French or Greek words, and was never a derivative of "]" in the original sense, which means "one who raises up, a deliverer" in Latin.<ref name="Lewis">Lewis, Charlton T. and Charles Short. ''A Latin Dictionary: Founded on Andrews’ Edition of Freund’s Latin Dictionary''. Oxford: Clarendon Press, 1984.</ref> Similarly, the root word "''scala''" does not mean "a flight of steps", but is defined by Lewis and Short’s ''A Latin Dictionary'' as the singular form of the plural noun "''scalae''", which denotes any of the following: "a flight of steps or stairs, a staircase; a ladder, a scaling-ladder."<ref name="Lewis" />
], Hong Kong]]
]


Jesse Reno also designed the first escalators installed in any underground subway system in the form of a ] escalator at ] in London in 1906. The experimental device never saw public use and its remains are now in the ]'s depot in ].<ref> London's Transport Museum Photographic Collection, "1906 Escalator Operated on Opening Day of Great Northern Picadilly and Brompton Railway, December 15, 1906."</ref><ref>{{Cite web |url=http://www.ltmcollection.org/photos/photo/photo.html?_IXSR_=6L57xpS_lAK&_IXMAXHITS_=1&IXinv=1998%2F84439&IXsummary=results%2Fresults&IXsearch=Spiral%20escalator&_IXFIRST_=1 |title=Photograph 1998/84439 - Photographic collection, London Transport Museum |access-date=December 10, 2019 |archive-url=https://web.archive.org/web/20160126064353/http://www.ltmcollection.org/photos/photo/photo.html?_IXSR_=6L57xpS_lAK&_IXMAXHITS_=1&IXinv=1998%2F84439&IXsummary=results%2Fresults&IXsearch=Spiral%20escalator&_IXFIRST_=1 |archive-date=January 26, 2016 |url-status=dead }}</ref>
The alleged intended ] 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 the character of trade-mark."<ref>Seeberger, Charles D. "Trade-mark for Passenger-Elevators." ''U. S. Trade-mark No. 34724.'' May 29, 1900. Available: http://uspto.gov</ref> That his initial specifications are ostensibly inconsistent, and since Otis Elevator Co. advertisements so frequently capitalized all of the letters in the word, suppositions about the "capital ‘e’" are difficult to formulate.


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 ] obtained West German, Japanese, and United States patents for his version of a spiral escalator by 1973. When interviewed for the '']'' 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.<ref>Hillinger, Charles. "Spiral Escalator May Be his Wheel of Fortune", ''Los Angeles Times,'' November 11, 1973: 3.</ref> ] received a European and a US patent for a spiral escalator in 1992.<ref>, {{patent|US|5158,67}}</ref>
====Derivatives of 'escalator'====
The ] "escalate" originated in 1922, and has two uses, the primary: "to climb or reach by means of an escalator" or "to travel on an escalator", and the secondary: "to increase or develop by successive stages; ''spec.'' to develop from 'conventional' warfare into nuclear warfare."<ref>"escalate, ''verb''." T''he Oxford English Dictionary''. 2nd ed. 1989. ''OED Online''. Oxford University Press Feb. 2007. <{{dead link|date=April 2013}}>.</ref> The latter definition was first printed in the '']'' in 1959, but grew to prominent use during the late 1960s and early 1970s.<ref>"escalate, ''verb''.²" ''The Oxford English Dictionary''. 2nd ed. 1989. ''OED Online''. Oxford University Press. Feb. 2007. <{{dead link|date=April 2013}}>.</ref>


The Mitsubishi Electric Corporation was most successful in its development of spiral or helical escalators, and it alone has sold them since the mid-1980s. The world's first practical spiral escalator—a Mitsubishi model—was installed in ], Japan, in 1985.<ref>{{cite web|url=http://www.mitsubishielectric.com/elevator/innovations/spiral_escalators.html |title=Elevators & Escalators |publisher=mitsubishielectric.com |access-date=September 18, 2012}}</ref> 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 the escalator path, avoiding excessive force on the top chain links and hence avoiding the geometry, length, and height limits of standard escalators.<ref>{{cite web|url=https://la-grazia.com/e-learning/en-115-standard-for-escalators-and-moving-walks/|title='Spiral' Escalator and Moving Walk could give crowds a lift|last=Harris|first=Stephen|date=23 December 2010|access-date=2012-03-15 }}</ref> ], San Francisco, California, United States, is the first spiral escalator in the Western Hemisphere.<ref>Sachner, Paul M. "Two on the Town: Heritage on the Garden, in Boston, and San Francisco Centre, in San Francisco", ''Architectural Record'', vol. 177, no. 6, May 1989: 122–127.</ref>
===Loss of trademark rights===
{{See also|Genericized trademark}}
In 1950, the landmark case '']'' precipitated the end of Otis's reign over exclusive use of the word "escalator", and simultaneously created a cautionary study for companies and individuals interested in trademark retention.<ref>Folsom, Ralph H. and Larry L. Teply. "Trademarked Generic Words", ''The Yale Law Journal'', Vol. 89, No. 7 (Jun. 1980): 1323–1359.</ref> Confirming the contention of the ], Assistant ] Murphy’s decision rejected the Otis Elevator Company’s 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 the Otis Elevator Co. had "used the term as a generic descriptive term…in a number of patents which been issued to them and…in their advertising matter."<ref>''Haughton Elevator Co. v. Seeberger''85 U. S. P. Q. (BNA) 80–81 (Dec. Comm. Pat. 1950).</ref> All trademark protections were removed from the word "escalator", the term was officially ], and it fell into the ].


Levytator, a design originating at ] in London, can move in straight lines or curves with or without rising or descending. The returning steps do not move underneath the in-use steps: rather, they provide steps for travel in the opposite direction, as in the Pahl spiral escalator patent.<ref>{{Cite web|date=2011-06-09|title=City University London unveils world's first freeform curved escalator {{!}} City University London|url=http://www.city.ac.uk/news/2010/sep/city-university-london-unveils-worlds-first-freeform-curved-escalator|url-status=dead|archive-url=https://web.archive.org/web/20110609010439/http://www.city.ac.uk/news/2010/sep/city-university-london-unveils-worlds-first-freeform-curved-escalator|archive-date=2011-06-09|access-date=2021-08-19|website=city.ac.uk}}</ref>
==Primary uses and application==


== Safety ==
===Department stores/shopping===
]
As noted above, a few escalator types were installed in major department stores (including Harrods) before the ''Expo''. Escalators proved instrumental in the layout and design of shopping venues in the twentieth century.
]]]


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 ]s, increasing the likelihood of entangling the clothing's loose end.<ref>{{cite web|url=http://www.delhimetrorail.com/commuters/passenger_safety.html|title=PASSENGER INFORMATION |access-date=2010-04-10|url-status=dead|archive-url=https://web.archive.org/web/20100406065615/http://delhimetrorail.com/commuters/passenger_safety.html|archive-date=April 6, 2010|df=mdy}}</ref> To prevent this, sari guards are built into most escalators in India.
By 1898, the first of Reno’s "inclined elevators" were incorporated into the ] store at ] and ]. This was the first retail application of the devices in the US, and no small coincidence, considering that Reno's primary financier was ], co-owner of the department store with brother ].<ref>Gusrae, G. B. "Moving Sidewalks", ''Architectural Record'', June 1956: 220.</ref>


Children wearing footwear such as ] and ] are especially at risk of being caught in escalator mechanisms.<ref name="ABC-Snow">{{cite web |url=http://abclocal.go.com/kgo/story?section=news/bizarre&id=4630653 |title=ABC7 News |publisher=KGO Bay Area and San Francisco News |access-date=2016-10-30 |url-status=dead |archive-url=https://web.archive.org/web/20131202231606/http://abclocal.go.com/kgo/story?section=news%2Fbizarre&id=4630653 |archive-date=December 2, 2013 |df=mdy }}</ref><ref name="ABC-AP">{{cite web|url=https://abcnews.go.com/Business/story?id=4694425&page=1 |title=Kids Hurt While Wearing Crocs on Escalators |publisher= ABC News |date=2008-04-21 |access-date=2016-10-30}}</ref> The softness of the shoe's material combined with the smaller size of ] makes this sort of accident especially common.<ref name="WMC-TV">{{cite web |url=http://www.wmctv.com/global/story.asp?s=5441435 |title=Experts recommend caution when wearing Crocs |publisher=WMC Action News 5 - Memphis, Tennessee |access-date=2016-10-30 |archive-url=https://web.archive.org/web/20120223142419/http://www.wmctv.com/global/story.asp?s=5441435 |archive-date=February 23, 2012 |url-status=dead }}</ref>
===Public transportation===
] escalator, 2010]]
The first "standard" escalator installed on the ] was a Seeberger model at ]. Noted above, London's Underground installed a rare spiral escalator designed by Reno, ] and ] for the ] in 1906; it was run for a short time but was taken out of service the same day it debuted.<ref>London's Transport Museum Photographic Collection, same as reference #21 above. See also Orton, Ray. ''Moving People from Street to Platform: 100 Years Underground'', Mobile, AL: Elevator World, Inc. 22-26, 2000.</ref>
The older lines of the London Underground had many escalators with wooden treads (ca. 1930s) until they were rapidly replaced following the ], noted above.


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 ] are sometimes installed in these areas. Fire protection of an escalator floor opening 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.
==Other applications==


] (pictured in 2006) in 2013.<ref>{{Cite web|date=2013-09-13|title=London's Underground's Last Wooden Escalator To Be Removed|url=https://londonist.com/2013/09/londons-undergrounds-last-wooden-escalator-to-be-removed|access-date=2021-10-24|website=Londonist|language=en}}</ref>]]
===Factories and other industrial production environments===
In 1905, the ] Wood Mill in ] (then "the largest single worsted mill in the world") utilized Otis' Seeberger-type "reversible" escalators to carry its workers between floors four times a day.<ref>"Lawrence will Add 25,000 to its Population within two Years", ''Boston Daily'', March 4, 1906: SM11.</ref> The machines did not run all day: rather, escalators ran solely to transport employees to/from midday meals and in/out of the mill. In its advertising, Otis Elevator Company hailed this unconventional use for its unique benefits to both workers and owners: "The profitable and practicable feature of the Escalator, from the viewpoint of the owner, is the increased efficiency of each operator due to the elimination of stair climbing."<ref>Otis Elevator Company, ''Otis Escalators''. New York: Otis Elevator Co., 1912: 9–10.</ref>


The ] of 1987 illustrated the demanding nature of escalator upkeep and the devices' propensity to collect "fluff" and other small debris when not properly maintained.<ref>{{Cite journal|last=Moodie|first=K.|date=1992-01-01|title=The King's Cross fire: damage assessment and overview of the technical investigation|journal=Fire Safety Journal|series=Special Issue: The King's Cross Underground Fire|volume=18|issue=1|pages=13–33|doi=10.1016/0379-7112(92)90045-E|bibcode=1992FirSJ..18...13M }}</ref> The ] determined that the fire started slowly, smoldering virtually undetected for a time, and then exploded into the ticket hall above in a previously unrecognised phenomenon now known as the "]". In the escalators' undercarriage, approximately {{convert|8800|kg}} of accumulated ] acted as a ] to a neglected buildup of interior lubricants; wood veneers, paper and plastic advertisements, solvent-based paint, plywood in the ticket hall, and ] combustion added to the impact of the calamity.<ref>”Building Design Editorial: the King’s Cross Inquiry", ''Building Design'', November 19, 1988: 9</ref> Following the report, older wooden escalators were removed from service in the ]. Additionally, sections of the London Underground that were actually below ground were made ]; ultimately, the whole system became a smoke-free zone.
===Military use===
In San Francisco, an escalator at ] was used to convey personnel between the first and third floors. At the time of its construction in 1948, it was touted thus: " highest lift of any industrial building in the world. It rises {{convert|42|ft|m|1|abbr=off|sp=us}}."<ref>{{cite web|last=Logistics |first=Telstar |url=http://www.flickr.com/photos/49502995517@N01/2266907 |title=Hunter's Point, Building 253, Shop floor escalator, 1948 &#124; Flickr - Photo Sharing! |publisher=Flickr |date= |accessdate=November 16, 2011}}</ref>


Some of longest and fastest escalators in Europe are found in ], and are set to be replaced with slower versions in order to meet modern safety standards.<ref>{{Cite web|date=2023-10-25|title= Fast-moving Escalators in Metro Station Namesti Miru |website=Prague Now |url=https://prague-now.com/history/fast-moving-escalators-in-metro-station-namesti-miru/ |url-status=live |archive-url= https://web.archive.org/web/20231203171835/https://prague-now.com/history/fast-moving-escalators-in-metro-station-namesti-miru/ |archive-date= Dec 3, 2023 }}</ref>
Escalators were also utilized on aircraft carriers such as the {{USS|Hornet|CV-12}}, to transport pilots from "ready rooms" to the flight deck.<ref>http://www.uss-hornet.org/ See also Goodwin, Jason. ''Otis: Giving Rise to the Modern City'', Chicago: Ivan R. Dee, 2001.</ref>
]]]


== Legislation ==
==Extant historic escalator models==
] ] in New York City holds some well-known historic escalators. The model shown here, retrofitted with metal steps in the 1990s, is among the oldest of the store's 40 escalators. Otis "L-type" escalators with distinctive wood treads (not shown) have operated in the store since 1927.]]
], Australia]]
A few notable examples of historic escalators still in operation include:


In the 1930s, at least one suit was filed against a department store, alleging that its escalators posed an ], responsible for a child's injury.<ref>”Negligence: Escalator Not an Attractive Nuisance", ''Michigan Law Review'', Vol. 38, No. 2 (Dec. 1939): 265&nbsp;– 267.</ref>
===Australia===
* ], ]
* ], ]


Despite their considerable scope, the two Congressional Acts regarding accessibility (the ] and the ]) did not directly affect escalators or their public installations. Since Section 504 of the Rehabilitation Act included public transportation systems, for a few years, the ] considered designs to retrofit existing escalators for ] access. Nonetheless, ]' 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.<ref>, U.S. Department of Justice, Civil Rights Division, 1998: 3.</ref>
===Europe===
* St. Anna Pedestrian Tunnel underneath the ] in ], Belgium. This tunnel was opened in 1933.
* ], ], England
:These escalators, manufactured by Waygood Otis in 1951, were "believed to be the longest single lift escalators in the world", at the time of installation. Presumably the first escalators in Britain designed specifically for cyclists, they were also the longest in the United Kingdom. At most, they may be the longest extant wooden escalators in the world, though they are no longer in working order.<ref>"Tyne Tunnel: Construction History." Tyne Tunnel, Internet. http://www.tynetunnel.info/wps/wcm/connect/Tunnel/Pedestrian+and+Cycle+Tunnels/History/. Accessed: November 9, 2008.</ref>
* ] ] in Moscow, Russia contains the oldest (1944) escalator of tonnel type still in use, with length of {{convert|65|m|ft|abbr=on}} and vertical rise of {{convert|32.5|m|ft|abbr=on}}.


In the United States and Canada, new escalators must abide by ] A17.1 standards,<ref>{{cite web|url=http://files.asme.org/Catalog/Codes/PrintBook/29151.pdf |first1=Edward A. |last1=Donoghue |title=ASME A17.1/CSA B44 Handbook |publisher=The American Society of Mechanical Engineers |date=2011-06-06 |access-date=2016-10-30}}</ref> and old/historic escalators must conform to the safety guidelines of ASME A17.3.<ref>{{cite web|url=http://files.asme.org/Catalog/Codes/PrintBook/29528.pdf |title=Safety Code for Existing Elevators and Escalators |publisher=The American Society of Mechanical Engineers |date=2011-07-22 |access-date=2016-10-30}}</ref> In Europe, the escalator safety code is ] 115.
===North America===
* ] department store, Otis L-type units with wood treads and replacement metal treads, ], ] (only in escalators heading upwards from the first to the seventh stories)
* ] department store (now Macy's), two {{convert|16|in|mm|0|adj=on}} Otis L-type units with original floorplates, several {{convert|40|in|mm|0|adj=on}} Otis escalators ca. 1950s, ]
* Westfield San Francisco Centre (formerly ]), chrome-and-glass escalator by ] for Otis, ]{{dubious|date=March 2013}}
* The Land Pavilion-Epcot,Glass escalator by Otis. Has stairs next to them. Not single file but is separated {{dubious|date=November 2012}}
* Tokyo Sesame Place-Glass escalator with ]'s mouth as the entrance. First escalator in a theme park {{dubious|2006|date=June 2013}} (now closed)


== Etiquette ==
==Escalators: superlatives==
{{main|Escalator etiquette}}
{{see also|Right- and left-hand traffic}}
], ], Japan]]


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,<ref>Mason, M. (2013). ''Walk the Lines: The London Underground, Overground''. London: Arrow Books. {{ISBN|978-0-099-55793-7}}</ref> riders in Canada, Germany, Hong Kong, Taiwan,<ref>{{cite web|url=http://www.sinosplice.com/life/archives/2010/03/23/stand-on-the-right-walk-on-the-left |title=Stand on the Right, Walk on the Left |publisher=Sinosplice |date=March 23, 2010 |access-date=November 16, 2011}}</ref> the United Kingdom,<ref>{{cite news|author=Jack Malvern |url=http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/film/london_film_festival/article6883065.ece |title=Mystery over Tube escalator etiquette cleared up by restored film |publisher= Times Online |date= October 21, 2009 |access-date=November 16, 2011 |location=London |url-status=dead |archive-url=https://web.archive.org/web/20110615070709/http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/film/london_film_festival/article6883065.ece |archive-date= Jun 15, 2011 }}</ref> France and the United States are expected to stand on the right and walk on the left.<ref>{{cite web|url=http://www.virtualtourist.com/travel/North_America/United_States_of_America/Washington_DC/Local_Customs-Washington_DC-Metro_Metro_Etiquette-BR-1.html |title=Metro / Metro Etiquette, Washington D.C. - Local Customs |publisher=VirtualTourist |access-date=November 16, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20070705092803/http://www.virtualtourist.com/travel/North_America/United_States_of_America/Washington_DC/Local_Customs-Washington_DC-Metro_Metro_Etiquette-BR-1.html |archive-date= Jul 5, 2007 }}</ref> However, in Australia and New Zealand, the opposite is the case.<ref>{{cite news|url=http://www.theage.com.au/news/opinion/keep-it-to-the-left/2005/07/28/1122143960027.html |website=The Age |title=Keep it to the left|access-date=October 30, 2010|location=Melbourne|first=Jim|last=Schembri|date=July 29, 2005}}</ref> Practice may differ from city to city within countries: in ], riders stand on the right, whereas in ] (and most other Japanese cities), riders stand on the left.<ref>{{cite web|author=Post Magazine |url=http://www.scmp.com/news/asia/east-asia/article/1852947/japans-terrible-sounding-plan-escalator-ettiquette-dont-walk |title='Don't walk. Stand where you like': Japan's terrible-sounding plan for escalator etiquette &#124; South China Morning Post |publisher=Scmp.com |date=2015-08-27 |access-date=2016-10-30}}</ref>
===Longest systems===
* ]: in Hong Kong, tens of thousands of commuters travel each work day between ], the ], and the ], a residential district hundreds of feet uphill, using this long distance system of escalators and ]s. It is the world's longest outdoor escalator ''system'' (not a single escalator span), at a total length of {{convert|2600|ft}}. It goes only one way at a time; the direction reverses depending on rush hour traffic direction.
* In December 2011, a network of six escalators of {{convert|1260|ft}} length, equivalent to 28 stories high, was opened in ], offering the 12,000 residents of Comuna 13 a six-minute ride to the city center compared to their previous 35-minute climb on foot.
* ], ]: an escalator system of {{convert|774|ft|m|abbr=on}} length and {{convert|387|ft|m|abbr=on}} height.
* ]: a long escalator system connecting two parts of the Park, with an overall length of {{convert|730|ft}}.


In certain high-traffic systems, including the ] and the ], escalator users are encouraged to stand on whichever side they choose, with the aim of preventing wear and tear and asymmetrical burdening.<ref>{{cite news|last1=Baier|first1=Viktor|title=Pohyblivé schody neboli eskalátory|url=http://www.dpp.cz/download-file/1158/01-leden-2008.pdf|access-date=10 November 2014|work=DP Kontakt|issue=1/2008|publisher=Prague public transport company|archive-date=10 November 2014|archive-url=https://web.archive.org/web/20141110201856/http://www.dpp.cz/download-file/1158/01-leden-2008.pdf|url-status=dead}}</ref> All Tokyo metro stations also have posters next to the escalators that ask users not to walk but instead to stand on either side.
===Longest individual escalators===
], ]]]


The practice of standing on one side and walking on the other may cause uneven wear on escalator mechanisms.<ref>{{cite news|last1=Cabanatuan|first1=Michael|title=BART: Walk-left, stand-right 'rule' wears out escalators|url=http://www.sfgate.com/bayarea/article/BART-Walk-left-stand-right-rule-wears-out-10870252.php|access-date=24 March 2017|work=SFGate|publisher=San Francisco Chronicle|date=19 January 2017}}</ref><ref>{{cite news|last1=Olmstead|first1=Molly|title=Head of D.C. Metro Says Escalators Too "Sensitive" for Passengers to Walk on Them|url=http://www.slate.com/blogs/moneybox/2017/03/23/head_of_d_c_metro_says_escalators_can_t_handle_being_walked_on.html|access-date=24 March 2017|work=]|date=24 March 2017}}</ref>
====World====
* The longest escalators in the world are installed in deep underground stations of the ]. Three stations have escalators up to {{convert|137|m|ft|abbr=on}} long and {{convert|68.5|m|ft|abbr=on}} high: ], ], and ].
**See also ] in the Europe section.
* The longest ''freestanding'' (supported only at the ends) escalator in the world is inside ]’s atrium in ]. It rises 8 stories and is {{convert|205|ft}} long. Originally built as the entrance to the ] '']'', the escalator is now used for ] studio tours.<ref>http://www.cnn.com</ref>


] trialed standing on both sides (no walking) for a period of several months in 2016. This increased capacity and eliminated queues approaching the escalator during peak travel times.<ref>{{cite web |title=Standing On The Right AND Left Of Holborn's Escalators |url=https://www.youtube.com/watch?v=cX11cxeW6hA |archive-url=https://ghostarchive.org/varchive/youtube/20211215/cX11cxeW6hA |archive-date=2021-12-15 |url-status=live|website=YouTube| date=21 April 2016 }}{{cbignore}}</ref> A follow-up report was released several months later with no recommendation to continue the practice.<ref>{{cite web |title=The Results Of The Holborn Standing-Only Escalator Trial Are In |url=https://londonist.com/london/transport/the-results-of-the-holborn-standing-escalator-trial-are-in |website=The Londonist|date=March 7, 2017 }}</ref>
====Asia====
* The longest escalator in ], ] and ] is in ]'s ]. It connects the concourse level with platform 1 which in turn connects to ]. It is {{convert|43|m|ft|abbr=on}} in length and {{convert|21.5|m|ft|abbr=on}} in depth.
* The ] station in the ] has one of the world's longest escalators. It is 60 meters high and 120 meters long.


====Australia==== == See also ==
* The longest set of single-span uninterrupted escalators in the ] is at ] underground railway station in ].


* ]
====Europe====
Several ] systems in Central and Eastern Europe feature very long escalators.
* The ] ]'s lower-level second exit escalator (a type ЛТ-2, circa 1965), lifts riders {{convert|65.7|m}}, or 743 steps, up a {{convert|131.4|m|adj=on}} &ndash; long incline.{{Citation needed|date=April 2008}}
* In the ] station of the ], the escalators are {{convert|126.8|m|ft|abbr=on}} or 740 steps long, and {{convert|63.4|m|ft|abbr=on}} high. It takes three minutes to transit.
* Three stations in ] have escalators up to {{convert|138|m|ft|abbr=on}} long and {{convert|69|m|ft|abbr=on}} high: ], ], and ].
* The longest escalator in ], and in ], is at the ] station at {{convert|285|ft}} long and {{convert|142.5|ft}} high.
* The longest escalator of a European shopping mall is at MyZeil, ], Germany, with a length of {{convert|150|ft}}.
* The tallest escalator on the London Underground system is at ] with a length of {{convert|200|ft}}, and a vertical rise of {{convert|90|ft}}.
* The longest wooden escalators in the United Kingdom are at the ], with a length of {{convert|197|ft}}. (See above)
* The longest escalators in ] are in the ], at ] with a length of {{convert|220|ft}} and in ], at ] station with a length of {{convert|210|ft}}.
* The largest "single truss escalator" is in the ] in ] in ], UK. It connects the ground floor with the second floor with only top and bottom supports.{{Citation needed|date=March 2008}}

====North and South America====
* The longest set of single-span uninterrupted escalators in the ] is at the ] station of the ] system. They are {{convert|230|ft|m}}<ref>. ]. Accessed September 14, 2010.</ref><ref name="WPSOL">The Washington Post. "Standing on the Left? You Must Be on Vacation", May 17, 2004, Washington, D.C.: http://www.washingtonpost.com/wp-dyn/articles/A31605-2004May16.html</ref> long with a vertical rise of {{convert|115|ft|m}},<ref name="WPSOL" /> and take what is variously described as 2 minutes and 45 seconds{{Citation needed|date=September 2009}} or nearly three-and-a-half minutes,<ref name=gwhatchet>Carroll, Caitlin. ''The GW Hatchet''. September 19, 2005.</ref> to ascend or descend without walking.

===Shortest examples===
According to ], the shortest escalator in the world is the "Puchicalator" in the ] shopping mall in ], Japan. Its vertical rise is only {{convert|32.8|in|cm}} and has 5 steps.

==Notable spiral escalator installations==
] ], Japan]]

===Asia===
* ], ]
* ] ], ]
* ], ], ]
* ], Japan
* ] shopping mall, Causeway Bay, ]
* ], South Korea
* ] hotel and casino, Cotai, ]
* ], ], ]
* ], ]

===North America===
* ], ], ], United States
* ], ], ], United States
* ], ], United States — the first such installation in the Western Hemisphere.<ref>Sachner, Paul M. "Two on the Town: Heritage on the Garden, in Boston, and San Francisco Centre, in San Francisco", ''Architectural Record'', vol. 177, no. 6, May 1989: 122–127.</ref>
* ], ], ] — the first in Canada.
* ], ], ], United States

==Etiquette==
{{see also|Right- and left-hand traffic}}
], ], Japan]]
On some busy systems, such as those in the UK,<ref>{{cite news|author=Susan Thompson Last updated November 16, 2011 3:39PM |url=http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/film/london_film_festival/article6883065.ece |title=The Times &#124; UK News, World News and Opinion |publisher=Entertainment.timesonline.co.uk |date=November 22, 2003 |accessdate=November 16, 2011 |location=London}}</ref><ref>{{cite web|url=http://golondon.about.com/od/londontransport/qt/standonright.htm |title=Stand On The Right |publisher=Golondon.about.com |date=June 14, 2010 |accessdate=November 16, 2011}}</ref> US,<ref>{{cite web|url=http://www.virtualtourist.com/travel/North_America/United_States_of_America/Washington_DC/Local_Customs-Washington_DC-Metro_Metro_Etiquette-BR-1.html |title=Metro / Metro Etiquette, Washington D.C. - Local Customs |publisher=VirtualTourist |date= |accessdate=November 16, 2011}}</ref> Germany{{citation needed|date=February 2014}}, Taiwan and Hong Kong,<ref>{{cite web|url=http://www.sinosplice.com/life/archives/2010/03/23/stand-on-the-right-walk-on-the-left |title=Stand on the Right, Walk on the Left |publisher=Sinosplice |date=March 23, 2010 |accessdate=November 16, 2011}}</ref> there is a ] policy of standing on the right. Often, this informal standard is reinforced by official regulations, though official enforcement is rarely required. In most of Japan including Tokyo, the policy is to stand on the left; however in Osaka they stand on the right.{{citation needed|date=November 2013}} Either way, the open side of the escalators is reserved for those riders walking and overtaking.

In the ], the official policy of standing on the right was formerly in effect, but was cancelled due to fears of increased wear and tear on asymmetrically burdened escalators.<ref>{{cite news|last1=Baier|first1=Viktor|title=Pohyblivé schody neboli eskalátory|url=http://www.dpp.cz/download-file/1158/01-leden-2008.pdf|accessdate=10 November 2014|work=DP Kontakt|issue=1/2008|publisher=Prague public transport company}}</ref>

The ] is to stand on the left.<ref>{{cite news|url=http://www.theage.com.au/news/opinion/keep-it-to-the-left/2005/07/28/1122143960027.html|title=Keep it to the left|publisher=http://www.theage.com.au|accessdate=October 30, 2010|location=Melbourne|first=Jim|last=Schembri|date=July 29, 2005}}</ref>

==See also==
{{div col}}
* ] (Hong Kong)
* ] * ]
* ] * ]
* ] * ]
* ]
* ] * ]
* ] * ]
* ] * ]
* ]
{{div col end}}


== References ==
==References and notes==
{{Reflist|2}}


{{reflist}}
==External links==
{{Wikiquote|Escalators}}
{{Commons category|Escalators}}
*
*{{citation |url=http://www.railwaywondersoftheworld.com/escalators.html |chapter=How escalators work |title=Railway Wonders of the World |year=1936 |pages=343–348 |editor-first=Clarence |editor-last=Winchester }} illustrated description of escalators on the London Underground and their advantages over lifts


== External links ==
{{Use mdy dates|date=April 2013}}
{{wiktionary|escalator}}
{{wikiquote|Escalators}}
{{commons category|Escalators}}


* "", Jun 21, 2007, by PomppuY on YouTube
]
* {{citation |chapter-url=http://www.railwaywondersoftheworld.com/escalators.html |chapter=How escalators work |title=Railway Wonders of the World |year=1936 |pages=343–348 |editor-first=Clarence |editor-last=Winchester |postscript=.}} Illustrated description of escalators on the London Underground and their advantages over lifts
]

{{Public transport}}
{{Authority control}}

]
] ]
] ]
]
]
] ]
] ]
]
] ]
]

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Rows of escalators at the World Trade Center in Dubai
Escalator in a metro station in Warsaw
Fujitec escalator in action, 2020
Escalators at the Christ the Redeemer statue in Rio de Janeiro, Brazil

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 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.

History

Inventors and manufacturers

Illustration from U.S. Patent#25,076: Revolving Stairs, issued August 9, 1859, to Nathan Ames

Nathan Ames, a patent attorney from Saugus, Massachusetts, 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 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 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 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 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 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 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 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 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 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 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 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.

Extant historic escalator models

Macy's Herald Square store in New York City holds some well-known historic escalators. The model shown here, retrofitted with metal steps in the 1990s, is among the oldest of the store's 40 escalators. Otis "L-type" escalators with distinctive wood treads (not shown) have operated in the store since 1927.
Wooden treads on a 1930s Otis escalator, formerly at Wynyard railway station, Sydney, Australia

Notable examples of historic escalators still in operation include:

Etymology

Authors and historians have offered multiple interpretations of 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 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 /ɛsˈkælətɔːr/ (ess-KAL-ə-tor). By 1906, Seeberger noted that the public had instead come to pronounce it /ˈɛskəleɪtɔːr/ (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, a staircase; a ladder, 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 the character of trade-mark." Otis Elevator Co. advertisements so frequently capitalized all of the letters in the word.

See also: Genericized trademark

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 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 been issued to them and... in their advertising matter." All trademark protections were removed from the word "escalator", the term was officially genericized, and it fell into the public domain.

Design

A curved escalator
"Crisscross" layout, Shanghai Museum
"Multiple parallel" layout, Holborn Station, London

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 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, 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 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 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:

  • Parallel (up and down escalators adjacent or nearby, often seen in perpendicular areas, metro stations and multilevel movie theaters);
  • Multiple parallel (banks of more than one escalator going in the same direction parallel to banks going the other direction);
  • Crisscross (escalators going in one direction "stacked" with escalators going the opposite direction oriented adjacent but perpendicular, frequently used in department stores or shopping centers).

Most countries require escalators to have moving handrails that keep pace with 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 the predominant flow of the crowd, or controlled automatically. In some setups, the direction is controlled by whoever arrives first.

Components

Escalator components
  • An escalator being repaired at Town Hall station in Sydney, Australia An escalator being repaired at Town Hall station in Sydney, Australia
  • A "freestanding" escalator reveals its inner components through the transparent truss. A "freestanding" escalator reveals its inner components through the transparent truss.
  • Escalator truss connects to the landing platform (lower left). Also visible: exposed drive gears (center) for steps and handrail drive (left). Escalator truss connects to the landing platform (lower left). Also visible: exposed drive gears (center) for steps and handrail drive (left).
  • View of an escalator's motor View of an escalator's motor
  • An escalator with its steps removed An escalator with its steps removed
  • An escalator equipped with a "bellows" handrail. The bracelets are colored grey, with occasional strings of black ones to appear as moving spacers, etc. An escalator equipped with a "bellows" handrail. The bracelets are colored grey, with occasional strings of black ones to appear as moving spacers, etc.

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 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 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 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 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 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 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 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 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 the machinery. Multiple solutions have been suggested for this issue, including coating with a low-friction material, employing bristles, and others.

An escalator under repair (Dallas, TX)

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 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 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 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 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 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.

Alternative designs

A spiral escalator in Times Square, Hong Kong
Spiral Escalator US Patent 5,158,167 (Pahl 1992) drawing

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 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 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 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 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 the in-use steps: rather, they provide steps for travel in the opposite direction, as in the Pahl spiral escalator patent.

Safety

Emergency stop button on an escalator in Korea
Escalator safety guidelines at Taipei Metro

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 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 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 last wooden escalators in the London Underground were removed from Greenford station (pictured in 2006) in 2013.

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 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 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.

One of longest and fastest Soviet-era escalators in Europe, within Náměstí Míru station in Prague

Legislation

In 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 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 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.

Etiquette

Main article: Escalator etiquette See also: Right- and left-hand traffic
Riders stand to the right on this escalator in Umeda, Osaka, Japan

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, 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 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 a period of several months in 2016. This increased capacity and eliminated queues approaching the escalator during peak travel times. A follow-up report was released several months later with no recommendation to continue the practice.

See also

References

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