Why is it that the handrail of an escalator never moves at the same speed as the steps themselves?

Question

Is it that hard to get them to travel at the same speed so your hand doesn't have to be moved back down when holding on? (Of course if I wasn't lazy and walked up the escalator I wouldn't notice this happening lol).

Answer 1

I am not sure that you want the correct answer to this question.

But here goes.

Escalators are the one most dangerous thing in a store. They operate from a motor at the bottem of the escalator driving a set of gears which form a conveyor belt of sorts. The teeth of those gears actual run under that hand rail as well as at the base of those hand rails. It is kind of like the bicycle chain on a ten speed bicycle. The more it gets used the more gets out of sink with the motor.

If you think about it, everytime somebody steps on that escalator you put strain on those gears. Then there are those people who walk up the escalator creating more strain on those gears. And, then there are those times during heavy traffic that those gears are flat out abused.

We are now getting to the specific answer to your question. The gears to the steps are locked up and down in place. The gears driving the hand rails are only locked down. They can therefore become slack and run fast for that reason. And now for the scary part, because they can become slack, in the event of an immediate stoppage of the escalator, your hand can as has happened in the past get trapped under the the rail and be cut by those gears running beneath the rubber grip. Of course if you don't have your hand on the rail you may get bucked off the escalator or worse yet get trapped in the safety plate at either end of the escalator. And if this is a temporary power failure it only gets worse.

Sadly, I had to study this for safety purposes in a retail store. I actually had a key to the escalator for emergency purposes such as these.

BTW, stay lazy, walking up the escalator is about as dangerous as it gets. Don't do that.

Answer 2

Actually, I've noticed the OPPOSITE is true -- the handrail of the escalator moves at the EXACT same speed as the steps. How could it be otherwise? :)

I mean, you wouldn't be able to even keep your hand on the rail, and still stand on your chosen step, if the rail kept moving away from you (either by being too fast or too slow)! I must admit I've no idea what you're talking about, because I have NEVER been on an escalator where the rail and steps didn't match.

I would guess that the ones you're talking about are either really old, or malfunctioning.

Answer 3

Man! I'm glad I'm not the only one that notices things like that. I asked the same question to my boyfriend and he looked at me like I was nuts and said that I was just imagining it. And I have no idea why they can't seem to get it right. But it kinda irritates me sometimes because every now and then, when I'm on the escalator, I'll lean on the handrail and then next thing you know, my body is being twisted backwards because the stupid stairs are moving faster than the handrail. You would think that the mechanism that rotates the stairs would be the same one that rotates the handrail, therefore moving them at the same time and speed. But I guess that just isn't the way it's done. I will rejoice the day I ride on an escalator and the rail and steps are moving at the same speed! lol....

Answer 4

I've been an engineer, and that has aways bothered me too. Either the hand rail mechanism is attached to the stair part (which would make sense) or it is driven by a separate motor. Either way, how hard would it be to coordinate the rate of speed to match the other?

Here is my GUESS. Perhaps the rates ARE perfectly corordinated when the escalator is installed. But, since the hand rail is made of a flexible (therefore stretchy) material, it eventually loosens, sags a bit underneath, and moves at a (get ready for this) LESSER apparent speed. My recollection of the difference in speed is that the rail moves slower. This makes sense to me because if the band making up the rail is stretched longer, the motor, or the attached mechanism is moving a longer band of material around each rotation.

Any REAL escalator engineers out there show me where I got it wrong?

Answer 5

There is a simple explaination here.

The original design of any escalator is to have the handrail move at the same speed as the steps. Over time, some parts can get worn down, so the driving mechanism that operates the handrail gets a little sloppy, or loose, and the handrail actually slips a bit on the drive pully. Some repairmen will adjust the pully correctly, and the fix is perfect. Some guys are a bit less concerned with proper repairs, so they do a slap-it-fast-and-get-out fix, resulting in poor performance.
It all comes down to proper maintenance. Doesn't it always as with anything in life???????????????????

Answer 6

It's all caused by the moon. When the moon is waxing, the handrail moves up faster, and when it is waning, the handrail moves slower. At the full moon and new moon, they move at exactly the same speed. This is because the moon's gravity does not affect the stairs as much as it affects the handrail, due to the greater weight of the stairs.

This only applies to escalators going up. On escalators going down, the effect would be reversed.

Answer 7

Escalators are actually a very complicated machine. All things being equal..the hand rails are supposed to move at precisely the same speed as the steps. If the ones you ridng aren't..maybe they need some tweaking.
"In addition to rotating the main chain loops, the electric motor in an escalator also moves the handrails. A handrail is simply a rubber conveyer belt that is looped around a series of wheels. This belt is precisely configured so that it moves at exactly the same speed as the steps, to give riders some stability."

Answer 8

This has never been my experience.

... the electric motor in an escalator also moves the handrails. A handrail is simply a rubber conveyer belt that is looped around a series of wheels. This belt is precisely configured so that it moves at exactly the same speed as the steps, to give riders some stability.

Answer 9

Most people grab the handrail first, before stepping on the steps.

Thus, by design, the handrail moves slower than the steps because it allows the person to get used to the motion of the escalator gradually.

Otherwise, if someone grabs the handrail, and it is moving as quickly as the steps, the difference in forward motion from a manual step to the accelerated step might cause the person to fall forward.

Answer 10

I was just thinking about that very thing a couple days ago, really. I think there are moving at the same speed but the handrail is on a shorter loop so the corresponding points on the handrail and the stairs do not remain corresponding. The stairs have further to go and it takes them longer to get there in spite of the fact that they're moving at the same rate of speed.