An escalator is a vertical transportation device in the form of a moving staircase – a conveyor which carries people between floors of a building. It consists of a motor-driven chain of individually linked steps. These steps are guided on either side by a pair of tracks which force them to remain horizontal. Main areas of usage include department stores, shopping malls, airports, railway stations, convention centers, hotels, arenas, stadiums, and public buildings.
Escalators, like moving walkways, move at constant speeds of around 0.3–0.6 meters per second. The typical angle of inclination of an escalator to the horizontal is 30 degrees, and the total difference in height can be about 18 meters or more. Modern escalators have single-piece aluminum or stainless steel steps that move on a system of tracks in a continuous loop. 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.
Nathan Ames, a patent solicitor from Saugus, Massachusetts, is credited with patenting the first "escalator" in 1859, although no working model of his design was ever built. In 1889, Leamon Souder 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.
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 built by the Otis Elevator Company in 1899.
Safety is a major concern in escalator design. There is a risk of foot injuries for children wearing footwear such as Crocs and flip-flops that might get caught in escalator mechanisms. This is due to the softness of the shoe's material combined with the smaller size of children's feet.
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. In addition, 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.
Most countries enforce periodic escalator inspections as a legal requirement. The time intervals between those periods differ from country to country, however, the basic principle is the same: safer transportation for everyone.
We, in RoyalCert, carry out our part of the public responsibility and conduct periodical escalator inspections to increase the safety of the devices we use every day.