Escalator
An escalator is a conveyor transport device to transport people, consisting of a staircase whose steps move up or down on tracks which keep them horizontal. Most escalators also have moving handrails which approximately keep pace with the movement of the steps. The direction of movement (up or down) can be permanently the same, or be controlled by personnel according to the time of day, or automatically be controlled by whoever arrives first, someone at the bottom or at the top (of course the system is programmed such that the direction is not reversed while somebody is on the escalator). In the last two cases there has to be an alternative nearby.
Charles Seeberger developed the escalator and installed the first one as an amusement ride at Coney Island, New York in 1897. He joined the Otis Elevator Company and they produced the first commercial escalator which won a first prize at the Paris 1900 Exposition Universelle in France.
Escalators in the London Underground used to have wooden steps, but this was changed after the Kings Cross fire at Kings Cross St Pancras tube station in 1987. Old escalators with wooden steps are still in use in some places, however, such as the Tyne Cyclist and Pedestrian Tunnel in Tyne and Wear, England. Modern escalators have metal steps in a continuous loop that move on tracks. Escalators are typically used in pairs with one going up and the other going down. Some modern escalators in stores and shopping malls have glass sides which allow their workings to be viewed. Although most escalators are straight, some shopping malls use curved versions.
When using escalators, passengers who wish to stand and let themselves be carried up or down should stand on one side to allow more impatient users to walk past them. However, which side varies from place to place. On the London Underground and Washington Metro, standees are asked to keep to the right.
There have been reports of people actually falling off a moving escalator or getting their shoe stuck in part of the escalator.
An extensive system of escalators and moving sidewalks form a public transport system in Hong Kong; see conveyor transport. This includes the Central-Mid-Levels escalator, the world's longest escalator at 800m.
The longest escalator in the Western Hemisphere is at the Wheaton station of the Washington Metro subway system. It is 230ft (70m) long.
Etymology
Escalator was originally a trademark combining the words escalade (an old term for using a ladder to scale a wall) and elevator.