Today’s Wonder of the Day was inspired by Jacquelyn from Pflugerville, TX. Jacquelyn Wonders, “How do escalators work?” Thanks for WONDERing with us, Jacquelyn!
Did you hear what one escalator said to the other? The ascending escalator thought things were looking up all day. This made the descending escalator sad, since he had felt down all day.
OK, so escalator jokes definitely have their ups and downs. But look on the positive side: an escalator can never break. It can only become stairs!
The first time kids encounter an escalator, it can seem like a magical contraption. You have to step onto a moving floor that suddenly becomes a moving staircase. At the top of the escalator, you step off and it disappears below your feet.
How does this work? Is it magic? Nope, it's just a marvel of science and technology. Let's take a closer look at exactly how escalators work.
Although escalators can be quite large and expensive to install and operate, they're fairly simple technologically. Basically, escalators are a variation of the simple conveyor belt.
Inside an escalator, a pair of chains wraps around two pairs of gears that are driven by an electric motor. The motor and chains sit within a metal structure known as the truss, which extends between the floors served by the escalator.
Unlike a conveyor belt, which moves a flat surface, the chains in an escalator move a series of steps. Each step has two sets of wheels that roll on separate tracks.
The upper wheels are connected to the moving chain that pulls them along. The bottom wheels roll along in a separate track that's spaced precisely to ensure that the steps always remain level.
The steps are also designed in such a way that they collapse on each other to create a flat platform at the top and bottom of the escalator. This makes it easier for escalator riders to get on and off the escalator safely.
To make the ride more stable, escalators also feature a handrail that moves at the same speed as the steps. The handrail consists of a rubber conveyor belt that loops around a series of wheels powered by the escalator's electric motor.
Although escalators can't move dozens of people many stories, they can move much larger groups of people shorter distances. Experts estimate that an escalator moving 145 feet per minute can carry about 10,000 people per hour.
So while they're not technologically complicated, escalators do seem to work like magic and make getting from one level to another in shopping malls and airports much easier. They haven't always been called escalators, though. Some early nicknames included "magic stairway," "traveling staircase," and "inclined elevator."