The secrets of elevator design

Making a high-quality elevator isn't just about designing something that can safely go from one floor to another. Elevators are service items. That means that when you design an elevator, you also have to design for people — both individual desires and needs, and the desires and needs of a variety of cultures.

If engineering is really about designing socio-technical systems, then elevators are big, fat, obvious reminder of that dynamic in play. In a profile written for the Wall Street Journal, author Kate Linebaugh describes the work of Theresa Christy, a mathematician and Otis Elevator research fellow.

You press a button and wait for your elevator. How long before you get impatient and agitated? Theresa Christy says 20 seconds.

As a mathematician steeped in the theories of vertical transportation at Otis Elevator Co., Ms. Christy, 55, has spent a quarter-century developing systems that make elevators run as perfectly as possible—which means getting most riders into a car in less than 20 seconds. "Traditionally, the wait time is the most important factor," she says. "The thing people hate the most is waiting."

... The challenges she deals with depend on the place. At a hotel in the holy city of Mecca in Saudi Arabia, she has to make sure that the elevators can clear a building quickly enough to get most people out five times a day for prayer.

Read the full story at The Wall Street Journal

Via Maria Konnikova

Image: Elevator, a Creative Commons Attribution (2.0) image from 25103209@N06's photostream


    1. God the hours I wasted on that broken, badly designed game.  I loved it so much.  I wish they would bring out a new version!

      1. I was also about to post about SimTower.  It actually had an official sequel by the name of Yoot Tower, named for Yoot Satio, the designer of the original game. (It was also released for the Game Boy Advance as “The Tower”, but that version is probably best forgotten.)

  1. Depends on what you call an “elevator”. I would argue that designing a high-quality cost-optimized elevator bank within a building is a surprising feat of engineering that requires much more than moving floor to floor quickly, but one single elevator will never ever be able to improve its wait time through mathematical models and only through moving quickly floor to floor. Increasing bandwidth of any widget requires multiple widgets used in concert with each other, and the elevator is no different.
    I mean, using a singleton of the Burj Khalifah’s elevators compared with a couple standard issue designs is where the user experience comes in. If I’m at a 50 story luxury hotel in a large city, they’re going to have 8-10 elevators and even then I’m stuck waiting as people leave for work in the morning or get back in the evening.

    1. I’ve heard about one Very tall building where you use a console to choose your floor, and it tells you which elevator number to go to. The system groups people by floor section, vastly reducing the need for express elevators to specific sections

  2. There’s a great bit on the NA Dr. Who novel “Transit” on the problems of the programming of elevators.  The elevator in question is in the mall of the Mars Dome.  One of the characters is escaping from a Cake Monster and just gets in the elevator ahead of it: slamming the “Close Door” button as she bounces off the back of the car.  The elevator, however, senses another incoming passenger, the Monster, and helpfully overrides the “Close Door” command in order to improve average waiting times.  The escapee then hits the “Emergency” button.  In an unspecified emergency the elevator ponders the risk of leaving the passenger in hand exposed to whatever the emergency is for the length of time it would take the incoming passenger to gain the safety of the elevator and decides that it’s now even *more* important to leave the door open for a bit.

    The monster takes a shot, using its inbuilt weaponry, to stop the girl from doing what is it she’s doing at the control panel: just hammering on the “Close Door” button.  This hits the back of the elevator.  Elevator sensors detect a large change in pressure to part of the car (the shot) and decides that the emergency is now most likely a blow-out of the dome.  Consulting actuarial tables for this scenario it now decides for an emergency door close and emergency speed evacuation to a subterranean level – leaving the evacuee slammed up to the roof of the car while it fills with deceleration foam for the end-of-the-shaft stop.

    A copy of the elevator program and a log of this run of it is sent off to the Dome’s Legal Affairs computer for use in the inevitable lawsuits from the family members of whoever it was (the Cake Monster) that had the door slammed in their face as they were running for the escaping elevator.

    Second-best piece of fantasy elevator fiction that I’ve ever read!

      1. Well, I thought that would have been obvious!  “The Intuitionist” by Colin Whitehead is an uplifting tale of race and gender issues and, above all, of elevators.

  3. The “surfboard feature” in the article sounds like it would be very useful in labs where dewars of liquid nitrogen are being moved from floor to floor. You can’t ride in the elevator with those, as there’s a risk that you’d suffocate if it got stuck- the nitrogen is constantly boiling, and would fill the confined space of the elevator car quite quickly.

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