Mechanical Engineering

How An Escalator Works

How humans are able to move from floor to floor using escalators

By: Megan Lai, Journalist

May 28, 2025

“Escalator” by compujeramey is marked with CC BY 2.0.

How do you get from floor to floor using malls? The answer, nowadays, is probably an elevator or an escalator. But how do escalators really work? How can they rise and compress at the top and bottom of the floor? Read on to find out.

The Components

An escalator is made up of many parts. Let’s start with the stairs. The stairs are usually made of rubber or a material with a good grip. The individual stair looks like a right angle triangular prism, with ridges on the top. The steps always stay flat while they are on top, and they are the surface that the people step on. Each step has two wheels on the edge of the stair, which helps guide each individual stair while they are in motion. On the top of each step, there is a pole that is attached to a step chain, which looks like a long chain with wheels attached to the side. The frames around the stairs are guided by the two tracks, the one on top holding the top corner of the stair, and the other on the bottom of the stair. The step chain goes around an outer ring, and the bottom track guiding the bottom of the stairs is inside the outer ring. Together, these two tracks help the stairs to revolve up and down.

The Mechanism

Now that the components have been covered, it’s time to move onto how the stairs revolve, and recede back into a flat path just when it reaches the beginning or the end of the escalator. The two important tracks in an escalator are the step chain track and the track guiding the bottom part of the stair. The distance between them differs at the top and the bottom of the staircase, which allows the height between the stairs to be adjusted. At the bottom of the escalator, there is also a motor which helps to move the entire escalator. Along with the escalator, the hand rail also moves at the same place as the escalator as it moves up or down.