Up and Then Down: The lives of elevators (2008) | Hacker News Reader

Up and Then Down: The lives of elevators (2008)

newyorker.com

26 pointsRONROC13 comments

I often get annoyed by an obviously inefficient elevator, doors closing too slow, not reacting to buttons, etc. and imagine the awesome scheduling logic I would write if I were in charge. Well, my dreams came true when I found this: https://play.elevatorsaga.com/ !

Closing doors on passenger elevators are limited to 17 ft/lb of kinetic energy for safety. Opening speed is not limited, and most high-use elevators open the doors much faster than they close them.

Interesting! I don't think the laggy feeling on most elevators is actually due to regulation, though - the elevators in my current apartment building are wicked fast, and it was built <10 years ago in SF so almost certainly code compliant.

- They're thrown at speed to exactly the right position, no separate leveling stage.

- Door opening is violently fast, as you mention.

- If you're stopping at a destination entered in error, you can press the door close button while the doors are opening and they will turn right back around. (Presumably disabled if someone has also called the elevator from that floor).

- If called to a floor and no one is there (no one crosses the threshold) the destination entered from that floor is canceled.

- The doors close almost immediately after someone gets in or out. (This might be an ADA thing; you can request more patience from the system by pressing the wheelchair button on the destination dispatch keypad while entering your floor).

Really the only thing I don't like is the poor accuracy on the touchscreen keypads in the elevator lobbies. Also there's no "enter" so if the second digit of your floor number doesn't register fast enough, you will also be stopping at the first digit. Ugh. Just give me real buttons. But overall it's a great system.

I also discovered a novel "slow elevator" pathology in college - a trickle of people arriving at the lobby level and pressing the call button would hold the elevator there indefinitely. It is frustrating when you're 3 seconds from an elevator that closes its doors and departs, but this is actually necessary! If it waited for everyone it would never get off the ground.

I don't think the laggy feeling on most elevators is actually due to regulation, though - the elevators in my current apartment building are wicked fast, and it was built <10 years ago in SF so almost certainly code compliant.

Lightweight elevator doors exist. "Lightweight panels generate lower kinetic energy for faster door cycling and less stress on door operating systems."[1] For the mass of the door, there's a top speed, and that's on the data plate for the door, so the installer can adjust the speed.

Most elevator injuries involve doors, so this is taken seriously. Elevator door force and kinetic energy standards, and measurement tools, per ASME A17.1-2013/CSA B44-13: [2]

Much real-world stuff works reliably because there are explicit, enforced standards. We need more of that in software for critical functions.

[1] https://www.columbiaelevator.com/doors

[2] https://www.elevatorbooks.com/wp-content/uploads/2019/02/EW1...

I stopped getting annoyed by elevators when I realized that there's nothing in my life so important that I have to elevate my blood pressure about waiting 30 seconds.

If I'm not wearing a badge, a fireman's helmet, or a stethoscope, absolutely nothing will change by me taking a few extra seconds to get to my destination.

I have a love for being in transit for a similar realisation, be it elevators, cars, trains or planes.

While in transit I am doing everything I possibly can, everything I am required to do to keep moving forward, in that moment of transit there are no further requirements, and there is peace.

Sim Tower may also interest you if you enjoyed that sort of game.

Sim Tower was awesome!

I think about this so often when I am waiting for elevators in high rise buildings. Thanks for posting this! I will definitely put my money where my mouth is and see how hard it really is!

I read a fascinating and well-written article about 10 years ago about a woman (a lawyer iirc) who stepped into an elevator in a New York office building late one evening. Halfway down, the elevator got stuck due to a warped frame, and then suddenly dropped several floors from the weight of the still-unwinding cable.

The elevator then proceeded down to the lobby, but the woman was severely injured. The building was deserted so it took her a long time to get medical help, and afterwards people would not believe her since nobody else witnessed the accident.

Wish I could find the article gain. It reminded me that there are many badly maintained elevators out there and the fact that more of them are not involved in accidents is a testament to their redundant design.

To this day I am wary of stepping into an elevator in an old/sketchy building.

I thought all elevators had a kind of mechanical fail safe brake that automatically engages if they start to fall too fast?

They do, but those are mostly intended in case somehow all the lift cables snap/detach/disappear. In that case the elevator would drop, the brakes would engage and slow the elevator down to a stop. In the story told you can easily imagine the elevator dropping and getting caught by the cables in a time frame shorter than what you'd need for the brakes to stop the elevator. A drop of just a foot could easily cause plenty of injuries.

EDIT: I should also mention that the mechanism I described above should not be confused with the overspeed governor which is located in the penthouse and wouldn't notice anything at all if the lift cage gets stuck.

> Up and Then Down: The lives of elevators (2008)

Surely "Ups and Downs"?

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