The escalator design is simple, with a motor-driven chain of individual steps that cycle on tracks. They travel through a curved section of track that keeps the steps horizontal until they reach the bottom landing, where the tracks separate and the stairs once again assume a staircase configuration.Escalators
also feature a handrail that provides a handhold for passengers. The handrail is usually pulled along its own track, but it may also be connected to the main drive gear by a series of pulleys.
In some escalators, the handrail has a comb bearer, which pushes back and up when something like stones or screws jams into it. The comb bearer can activate limit switches that stop the escalator in case of an emergency.
It’s also common to stack escalators together, which minimizes space requirements. Crisscross layouts of escalators are sometimes used in shopping malls, for example at Mahboonkrong Center in Bangkok.
In addition, escalators can be sheltered from the elements by installing heating systems to prevent accumulation of snow and ice on the steps, landings and skirt deflector devices, as well as small, targeted clean agent automatic extinguishing systems within the dust collection and engineer pit areas.