How Does an Escalator Work?
An escalator is an endless chain of moving steps pulled round and round by a strong electric motor. An escalator is really just like a conveyor belt. Each step has wheels that run along a metal track as the chain of steps is pulled along. At the top and bottom of the escalator, the steps flatten out to make a moving platform level with the floor. This makes it easy to step on and off.
The steps then roll on underneath the escalator, and continue their trip around. Flexible handrails move around at the same speed as the steps. The handrails help passengers keep their balance on the moving steps. What’s tricky about escalators is keeping the steps level while they’re going up the slope (so you’re not tilted). The other trick is getting them to stay level at the beginning and end of the ride so people can get on and off safely.
The escalator system isn’t nearly as good as an elevator at lifting people dozens of stories, but it is much better at moving people a short distance. This is because of the escalator’s high loading rate. Once an elevator is filled up, you have to wait for it to reach its floor and return before anybody else can get on. On an escalator, as soon as you load one person on, there’s space for another.
Escalator speeds vary from about 90 feet per minute to 180 feet per minute (27 to 55 meters per minute). An escalator moving 145 feet (44 m) per minute can carry more than 10,000 people an hour — many more people than a standard elevator.