Waiting for a lift to work − 21 January, 2006
This morning I walked along the 36-room corridor to the array of lifts at the end and pressed the elevator down button. As soon as you press the button, a light above the lift predicted to arrive first activates. A couple of minutes pass and I see lifts that aren’t going to stop at my floor pass up and pass down. Five minutes pass before the predicted lift arrives. The doors open to a jam-packed carriage, a look of unsympathetic apology and the doors close again. Understanding that this is the rush-hour, I patiently press the down button again, watch several lifts go (up I think), and wait a further five minutes. It was on the fifth arrival that I eventually struck lucky and the lift had enough space to take me down the requisite 22 floors! Whilst waiting for 15 minutes to hitch my ride, it struck me that the description of Tokyo lifts as plumb-lines was more accurate than I realised; these elevators are definitely long waits.
I can see why elevator engineering is becoming more and more sophisticated: Imagine 45 stories each with an occupancy of 40 people; that’s 1800 people! If you think that a quarter of those people want to go to work at the same time, then you have 450 people in a short period wanting to share 8 lifts (my four taking the bottom 25 stories). A lift can take about 10 people. So that’s around 6 lift journeys per lift to transport all of those people. Now, the worst case (i.e. rush hour), there are people requesting the lift on every floor. So the lift goes to the top and works its way earthward, stopping at every floor! If it takes 10 people to fill a lift, and the average number of people getting on every time it stops is about half a lift-full (i.e. 5), and it takes 10 seconds for embarkation then it takes 20 seconds to fill the lift. Once the lift is full, it still stops at every floor, which takes 5 seconds for the doors to open, the inhabitants to raise their eyebrows in that apologetic, “I’m sorry that I managed to get a space in here and you didn’t, but I really have to get to work” manner and the doors to close again. It has to stop a further 23 times – which is a total of about 2 minutes. It takes 1 second to traverse between floors, so that’s another 45 seconds, and then another 10 seconds for disembarkation.
Total time for one rush-hour journey:
Initial lift arrival – 25 seconds
Embarkation 1 – 10 seconds
Embarkation 2 – 10 seconds
Earthward plummet – 2 minutes
Disembarkation – 10 seconds
Call it 3 minutes… 5 journeys – oh, surprise, surprise: 15 minutes!!!!
For everything else, there’s the stairs!
The sad, analytical person in me asks, “Why can’t they detect when the lift is full and not stop at every floor?” Implementing that would reduce the journey time (and wear on the doors!) dramatically. Oh well.
I think it’s ironic that watching an array of lifts from the outside with each lift sliding up and down its rail, looks like a giant abacus being used for some simple calculations.
PS. For the saddos amongst you (you know who you are…) please don’t try to pick holes in my lift-journey-interval model. It’s Saturday morning and I just wanted to make a point!
I can see why elevator engineering is becoming more and more sophisticated: Imagine 45 stories each with an occupancy of 40 people; that’s 1800 people! If you think that a quarter of those people want to go to work at the same time, then you have 450 people in a short period wanting to share 8 lifts (my four taking the bottom 25 stories). A lift can take about 10 people. So that’s around 6 lift journeys per lift to transport all of those people. Now, the worst case (i.e. rush hour), there are people requesting the lift on every floor. So the lift goes to the top and works its way earthward, stopping at every floor! If it takes 10 people to fill a lift, and the average number of people getting on every time it stops is about half a lift-full (i.e. 5), and it takes 10 seconds for embarkation then it takes 20 seconds to fill the lift. Once the lift is full, it still stops at every floor, which takes 5 seconds for the doors to open, the inhabitants to raise their eyebrows in that apologetic, “I’m sorry that I managed to get a space in here and you didn’t, but I really have to get to work” manner and the doors to close again. It has to stop a further 23 times – which is a total of about 2 minutes. It takes 1 second to traverse between floors, so that’s another 45 seconds, and then another 10 seconds for disembarkation.
Total time for one rush-hour journey:
Initial lift arrival – 25 seconds
Embarkation 1 – 10 seconds
Embarkation 2 – 10 seconds
Earthward plummet – 2 minutes
Disembarkation – 10 seconds
Call it 3 minutes… 5 journeys – oh, surprise, surprise: 15 minutes!!!!
For everything else, there’s the stairs!
The sad, analytical person in me asks, “Why can’t they detect when the lift is full and not stop at every floor?” Implementing that would reduce the journey time (and wear on the doors!) dramatically. Oh well.
I think it’s ironic that watching an array of lifts from the outside with each lift sliding up and down its rail, looks like a giant abacus being used for some simple calculations.
PS. For the saddos amongst you (you know who you are…) please don’t try to pick holes in my lift-journey-interval model. It’s Saturday morning and I just wanted to make a point!
