Are there any escalator experts on the forum?

[Deleted]

I've observed a perplexing and common mechanical inconsistency in escalators and am seeking insights from an expert in the field.

Most escalators I use feature a handrail that moves noticeably faster than the steps/conveyor.

You can see a video demonstrating this phenomenon here: [Insert Link to Video Here]

I've speculated that this design choice might be a safety feature—to subtly pull a passenger forward so that if they lose balance, they fall onto the steps rather than backward. However, this answer is unsatisfying for several reasons:

1. Safety Risk: Why risk causing a slight imbalance or toppling a passenger by deliberately mismatching the speeds?
2. Engineering Pride: From a design and manufacturing perspective, achieving a simple 1:1 speed ratio between the belt and the handrail seems like a fundamental goal for precision and quality.
3. Mechanical Complexity: Making the handrail move slightly faster requires an additional gearing mechanism to produce the necessary speed differential, complicating what should be a straightforward drive system.

The engineering and safety logic behind this common mismatch eludes me. I'm hoping someone with technical knowledge can shed light on this issue. Perhaps we can "escalate" this query for a definitive answer!

 

[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.

 

[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?

 

[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

 

[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.

 

[CJ_London]

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.

I presume that is going up - going down you will be leaning into the abyss

 

[Cotswold]

I presume that is going up - going down you will be leaning into the abyss

Correct!

 

[Isaac]

Just went down one yesterday at MSP airport where the hand rest was going backwards (up). Strange feeling. But I was so tired, I barely noticed it.

Had a nice Memorial holiday weekend visiting my parents in Wisconsin. Such a beautiful, beautiful land. Wow!

One sight to behold was, along the side of the roadway on a fast moving dual highway, there were a lot of Deer killed by cars - but the sight to behold was a full-size, stretched out, totally recognizable Black Bear also killed on the side of the road! Weird. I've only seen a black bear twice in real life - this time (dead), and once fully alive running across the road in the indescribable gorgeous wilderness of eastern and NE'n Arizona and New Mexico. Jogged across the highway in front of our car and then grabbed the concrete barrier at the edge and tumbled right over like he did it every day!

 

[Isaac]

Very very interesting, I wonder if it just made all that crap up lol

 

[Cliff67]

Having previously worked for London Underground for 18 years in various engineering departments including Lifts and Escalators, the explanation by the Chief Engineer was simple "They just do, so accept it and stop asking stupid questions" .

Over the years I've found out that it is really as Uncle Gizmo's post #25, a mixture of mechanical and psychological reasons.

During a station modernization we once came across a bricked chamber that contained the bottom few steps of a spiral escalator the Victorians were trying to make. I presume the whole idea was abandoned as not possible, but who knows.

Just as a side note: London transport hired a 1 legged Boar war veteran in 1912 called Bumper Harris to ride the first escalator in Earls Court.
The rationale was to ride escalators at Earl's Court station to demonstrate their safety to prove they were safe for public use.
However...people who saw him, thought he had lost a leg using the escalator and refused to use them for a long time. They were very nearly a failure