Why is it that the handrails of an escalator don’t move at the same rate as the actual steps? If you get on and hold on tight, after a few seconds your hand would be ten feet away from your feet. Where’s the logic in that?
Well, it is preferable that they do run at the same rate, for the reason you’ve expressed. But there is nothing inherent in the concept of the rail that forces it to move at the same rate. Indeed, it needs to be geared so that the rate the rail moves around the wheel at the end makes it move as fast as the rate the steps move around their turning device.
Usually, they match up pretty well. When they don’t, it’s because the adjustments aren’t quite exact. That gets VERY annoying on long moving walkways, like in airports.
I’ve never seen an escalator and rail that were that far out of sync. You sure you aren’t standing on the up escalator and reaching over to hold the down rail?
I agree it’s annoying when they’re out of sync, but frankly, I’m amazed that they’re so often perfectly synchronized, especially the ones that are abused a million times a day by people who sit/slide/skateboard on the rails.
That’s the walkway’s way of telling you you’re not supposed to stand on them like a bump on a pickle. :mad:
You are less likely to zone out and go to sleep if the handrail keeps making you adjust.
What I hate hate hate is when the damn handrail just randomly stops every now and then… so suddenly your precariously balanced bags on your shoulder are thrown from their perch.
That only happens infrequently though, and mostly on ye olde schoole escalators around here.
The diagram here shows a basic system with the two moving parts being driven from the same source. The resulting velocity of the handrail on the ‘public’ straight run is not necessarily going to match the steps exactly. Whether this is worsened on long escalators (and airport walkways as noted, which tend to also be very long), I don’t know. I’d have thought that if anything, the differences would be smaller because ratios would be closer to one another. But then again, it’s more noticeable if you’re stood there for a long time and the handrail creeps ahead.
The ratios aren’t dependant on the length of the escalator or walkway, only of the gear (or belt) train that drives the system at one point.
If escalator X is twice the length of escaltor Y, but both use identical mechanisms of the kind in my link, then the ratio of the length of the handrail to the walkway is going to be different, unless it’s been set up to be 1:1 anyway. To keep the ratio the same, you’d have to increase the size of the handrail drive in proportion to the length of the escalator.
The velocity of the handrail is not in any way dependent on its length.
Are we talking about two different things?
On further looking-at-diagrams, I realise you’re quite right! Whoooops.
This is a deliberate design decision. Escalator handrails are supposed to go faster than the steps. It was discovered early on in the history of escalators that this was needed.
Generally, they are only slightly faster than the steps. If properly adjusted.
I don’t know.
Some people say it’s to get people to walk up the escalator instead of standing, but officially, the escalator companies safety rules say that you should stand, not walk on escalators.
I can see how the rail running slightly faster could be a good distraction against vertigo on long escalators. However, it’s going to have to run just as fast on the way down!
Wikipedia doesn’t seem to say, either, but does mention the speeds aren’t the same. Odd.
Unless they just run the “up” escalator backwards.
Then people would fall off the bottom
What are you two talking about? That makes no sense.
All modern escalators are designed to run in either the up or down direction; all it takes is for the operator to throw a switch. Most are reversed at least occasionally, during maintenance or repair work.
Just a bit of friendly banter since we weren’t on the same page earlier in the thread.
I still want to know why the rail and steps are intentionally different speeds, though.
You are allowed to stand to the right, walk to the left. Sometimes, standing is an ok option. :rolleyes: