In these days of supposed energy conservation, I’m continually amazed at the number of escalators I see running continuously. The technology exists to have them start when someone enters and stop after enough time has elapsed for the last person on to get to the top or bottom, so why isn’t it implemented? I’m sure it’s done in some places, but I’ve never seen it…
Some of the escalators in the Montreal Metro system have an energy-conservation mode where they slow down to a crawl when there’s nobody on. When you step on, you’ll feel it speed up a little until it’s going at normal speed, and it waits a minute or two before slowing back down again.
I’ve never seen that anywhere else, though.
Some escalators in the NYC subway system have this feature.
But most of them, in order to save energy, never run at all.
Any device (probably infrared) incorporated into an escalator to toggle it between on and off would have to conform to ASME A17.1. It would have to be designed, produced, and tested according to said standards. It probably wouldn’t be cost effective to retrofit old escalators, and having the additional feature in a newly installed escalator isn’t a huge selling point. In short, there’s not really a market for it.
Logistically, when I walk up to an escalator, I start timing my step four to five strides back. If the escalator didn’t start moving until I was only one stride away, the transition would be balky at best.
Finally, it may actually be more efficient to have it run continuously. From an energy standpoint, it takes quite a bit more energy to accelerate a mass than to maintain a steady rate (think highway vs. city gas mileage). In addition, when calculating product life, start up and shut down of a system may be equivalent to an hour or more of operation, requiring higher maintenance overhead (think diesel engines being left to run instead of being shut off, even for stops as long as 20 minutes).
I’ve seen these used in Calgary Airport. They’re a little odd at first–there you are with luggage, needing to go up or down a floor, and the escalator’s broken! Look how slowly it’s moving! No, just go step on it, and it will get moving at normal speed. Frequent travellers through Calgary (or, I should add, those who have travelled the Montreal Metro ) are used to them, but they do confuse newcomers to the airport.
I do recall a test project in the Toronto subway years ago–it was an escalator that was stopped, normally. If somebody at the top stepped on it, the escalator would start and go down; if somebody at the bottom stepped on it, the escalator would start and go up. Obviously, this one did start and stop automatically, but I guess the drawbacks outweighed the positives in the test, since I never saw such escalators installed through the Toronto subway and that one disappeared after a year or two of service.
Here in DC we have these nifty overheight vehicle signs (something like this) that are supposed to turn on and flash a message whenever a truck might not be able to clear an underpass. The problem is, the height sensors are mounted along the side of the road and quickly get caked with emissions. Result: the sign flashes all the time.
I suspect that whatever sensor would be used to detect the presense of people anywhere along the length of the escalator would encounter the same problem unless the city wants to pay people to wipe them down every few days.
The cost of upkeep outweighs the benefit.
It’s common in Europe. Actually, I found it disconcerting at first. “Why are all the escalators broken?” I thought. Then I tried stepping on one, and it started.
Ed
I disagree. Grocery store doors that open automatically by using Xband radar don’t get caked.
Just thought I’d add that I think these are triggered by weight on a plate before you get to the escalator. Yes, you do have to wait a second or so for it to get started before you time your step.
And there aren’t a lot of escalators at the sides of roads…
They’re pretty much standard in Japan as well. Typically there are a pair of chest-high poles about a meter or two from the start of the escalator with some sort of motion sensor to get them up to speed before you reach the first step.
I can actually think of one, in Hong Kong. The sidewalk is so steep that they actually put in an escalator.
Zurich uses them, in heavily trafficed areas too, like the airport. It startled me the first couple of times I walked up to one, but they seemed to work well.
Actually saw one in a shopping center outside of Bangkok. My son and I had a lot of fun playing with it. If developing countries even have them, then the US should have them.
They’re pretty standard here.
The escalators are either not turning, or turning at a slow crawl. All the malls, multiplexes, etc. have a pressure sensor at the entry point of their escalators - you can feel the floor plate depressing ever so slightly. It only takes a moment for the thing to accelarate to normal speed. It’s a fairly easy calculation for the escalator to know when to slow down again after the last time the floor plate was depressed.
It helps that very few, if any, escalators existed in India until a few years ago. Had they been commonplace 10 years ago, I doubt we’d see energy-saving solutions of this sort in place now.
I’m thinking of the subway system, which is where I see escalators go for long periods of time without passengers. Everything down there has a fine layer of grit on it.
Regardless, I think this would be one of those neat ideas that takes millions of dollars to implement, then promptly falls into disrepair and never gets fixed. There would be a public outcry for wasting tax dollars on gadgetry when Metro has enough trouble just keeping the escalators & elevators running at all.
I actually think of them as “European escalators”. They seem to be as common as muck in Sweden, Germany, the Netherlands, Spain, and I even came across a few in China. I don’t believe I have ever encountered them in the UK or US - which seems kinda odd since most of them are probably made by Otis, Kone and ThyssenKrupp anyhow.
But all these other countries somehow seem to have a population that can avoid maiming themselves then suing everyone in sight because they (the maimees)didn’t have the sense to avoid maiming themselves. How do they manage that?
Ditto.
That’s a good idea. But actually, the maintanence of the escalator itself is pretty huge. In fact, it’s so much money that no one, except airports, is going to put up an escalator that isn’t almost continuously used. In which case, of course, the auto stop-start doesn’t help much. I’ve seen it once at a Korean airport, tho.