Are there any escalator experts on the forum?

[Uncle Gizmo]

Are there any escalator experts on the forum? I ask because I have discovered a perplexing issue with escalators.

Follow the link to Twitter where you can see a video showing that the escalator handrail moves faster than the escalator conveyor:-

https://twitter.com/x/status/1659937984559415297

For many years now I have noticed that most escalators I go on, the handrail appears to move slightly faster than the conveyor. I suspect it's done so that any unwary passenger that holds on to the rail for too long is pulled forward so that if they lose their balance they fall forward and not backwards. However that's not a very satisfactory answer to me because why? Why risk being responsible for toppling somebody on an escalator. Also what about pride in your workmanship? It would be a matter of Pride for me to make sure that the handrail moved at exactly the same speed as the conveyor. And the final issue, if the two parts of the escalator move at the same speed then you would expect the gearing to be a simple straightforward drive. However, to make the handrail moves slightly faster there must be some sort of extra gearing mechanism to produce this slight increase in Speed. So it doesn't make sense on another level. I'm hoping that someone here will be able to escalate this!

 

[jdraw]

Tony,

I know nothing of escalators.
But if the handrail is longer than the stairs that could be the cause.
I googled,
Showing results for is an escalator handrail same length as stairs
Search instead for is an escalator hand rail same length as stairs
and found:
Why does the handrail of an escalator travel faster than the steps? BECAUSE the total distance the handrail has to go is longer than that of the steps, and as both circuits have to be completed in the same time it has to move faster.

 

[KitaYama]

Toshiba Elevatora QA (translated by google)

──I feel that the speed of the moving handrail is different from that of the steps, but is the driving mechanism the same?

The moving handrail also uses the rotational force of the motor. Ideally, the moving handrail and steps should continue to move at the same speed all the time, but the moving handrail inevitably slows down due to belt elongation and wear. If the handrail is delayed, the user who is holding the handrail may fall backwards, so the speed of the handrail is adjusted so that it leads slightly ahead of the steps.

 

[KitaYama]

it would be a matter of Pride for me to make sure that the handrail moved at exactly the same speed as the conveyor

When you're a designer, safety comes first. Not your pride.

As explained above, making it faster keeps the user safer.
In my profession, I'd be fired the moment I think about my pride over the safety of the users.

 

[Uncle Gizmo]

There are various explanations for this phenomenon.

In the second link you provided @jdraw , I discovered this snippet on Quora:-

Extract:-
Let’s assume that when the rubber on the drive wheel wears down by 3 mm (1/8″), the handrail lags 80 mm (3″) over the course of 8 m (26 ft). That’s about 1%.

Some standards require that the speed should not deviate more than 2%. Some standards specify a load (a force) which should not slow down the handrail. Now, considering that the drive wheel will wear down, and that some slippage may occur due to dust and grease, the specification for a brand new drive wheel is probably adjusted ‘to be on the safe side’, causing the handrail to run 1–2% faster than the stairs. By targeting the new drive wheel at +2%, one could get double the service life out of it.

Uncle Gizmo summarising:-
The handrail is a long piece of rubber without any toothed arrangement. Therefore, it relies on friction to drive it. Over time, this friction causes wear on the drive wheel. This results in a gradual reduction in the drive wheel diameter, and it follows, in the handrail speed.

 

[Cotswold]

I don't see this as a big deal. Many escalators in the UK do this. In fact I'll usually test them out of interest just to see how far I lean forward by the time it ends. Presumably the motors driving the stairs are either different to the handrail motors, or they are linked via a set of adjustable gears.

Most of the handrails disappointingly are fairly well synced to the stairs though. I'll often to amuse myself to see if the rail and stair get there at the same time. Interestingly, or maybe not, I've never come across one where the feet move faster than the rail. Small things amuse small minds you could say. But I'm not good at inactivity, so always need to be doing something

I can't see that it would be a problem with anyone. Surely even a politician, or a dopy tradesman would spot their hand was advancing beyond their feet and let go of the rail for a second so their feet catch up before they fall on their face? Mind you you could take the stairs, which will probably be quicker. In a local store there are two short 12foot escalators with stairs at each side. You always get to the next level quicker by using the stairs. Where possible I'll not just stand anyway, I'll walk up and down to save time and only test the rail speed if everyone in front is just stood in suspended animation and I can't get past them.

Mind you with all this Covid fear stuff, should you hold onto any handrail anymore?

 

[Uncle Gizmo]

I'll usually test them out of interest just to see how far I lean forward by the time it ends.

I'm glad to see I'm not the only one with this fascination for the escalator rail speed!

 

[Uncle Gizmo]

Mind you with all this Covid fear stuff, should you hold onto any handrail anymore?

I wouldn't be surprised to find that some States have ordered that all escalators should be switched off for this very reason!

Edit:-
I know it doesn't make sense, it was a political comment....

 

[Uncle Gizmo]

Now this begs another question. From the video you will see that the escalator rail has round dots painted or stuck on it. I haven't seen these before. They seem to be something new. Are they there for aesthetics or some other reason? Could they be there to let the unwary know that the rail is moving! If that's the case, isn't that a bit woke? Is wokness creeping its way into the escalator industry?

What next? Escalators with barriers to stop hormonally driven teenagers looking up skirts?

 

[Lightwave]

Funny what people notice - I often muse about that as well.

 

[Minty]

Now this begs another question. From the video you will see that the escalator rail has round dots painted or stuck on it. I haven't seen these before. They seem to be something new. Are they there for aesthetics or some other reason? Could they be there to let the unwary know that the rail is moving! If that's the case, isn't that a bit woke? Is wokness creeping its way into the escalator industry?

What next? Escalators with barriers to stop hormonally driven teenagers looking up skirts?

I've noticed the red dots before and I think they have been around for years.

 

[CJ_London]

probably there as a marker so you can measure it's speed, otherwise how would you track a belt's position? Seem to recall timing belts on car engines also have dot

 

[Cotswold]

I wouldn't be surprised to find that some States have ordered that all escalators should be switched off for this very reason!

Edit:-
I know it doesn't make sense, it was a political comment....

I wouldn't be surprised if "they" didn't bring in some rule the next time. I can never understand is, why it is always the stupid people who get to make the rules?

Like the advice of not touching a parcel or mail delivered for days in case germs are included. But it was OK to order and have food delivered, knowing full well that those boxes would be opened and the contents thrown down their throats in minutes. In fact it is one one of my theories that fast food deliveries spread the virus faster than anything else.

 

[jdraw]

I tend to agree with CJ--"marker so you can measure it's speed,". If the hand rail/rubber is monochrome, and no surface identifier(s), then measuring could be an issue. With the mark(s), a sensor could monitor rail speed and adjust to keep it within spec if/when speed changes.

 

[Isaac]

all I can say UG is I noticed the same thing, but only on some of them. I just assume it's a sloppy or imperfect calibration/configuration

 

[Uncle Gizmo]

all I can say UG is I noticed the same thing, but only on some of them

The degree of advancement will depend on how long it has been since the escalator has had a service.

If a new drive wheel is fitted during the service, then I assume that you would have a 1 or 2% advancement of the moving rail.

Over time the drive wheel will wear away and the advancement decrease. I would guess until it's running at the same speed as the conveyor or possibly, even at a slower speed.

 

[Isaac]

Interesting.
Also interesting: Why are so many damn escalators turned off? Looks so inviting, only to find it is out of service and you walk up the darn thing.
Every time in Dick's Sporting Goods (a real store in the USA, but the staff are surprisingly nice..)

 

[JonXL]

I've never noticed this. The difference must not amount to much over the course of the ride...?

 

[Cotswold]

@JonXL
I've been on a couple where my left arm was stretched out and I was starting to lean forward as well. Have to say these little experiments of mine for some reason that isn't quite clear, infuriate my wife. As does my walking up or down instead of standing. The steps never seem as high when they are moving as when they are not working. Sad really but like I say, small things amuse small minds. Mind you shopping isn't my favourite pastime, more of a pointless chore that should be completed in the shortest possible time.

 

[AccessBlaster]

I do not use the escalators hand rail as a grab handle unless I am exiting, otherwise I let it slip through my hand.