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That's a pretty misleading headline. It wasn't a free-fall, and it doesn't sound like the passengers were even injured when it came to a stop. From the articl

That's a pretty misleading headline. It wasn't a free-fall, and it doesn't sound like the passengers were even injured when it came to a stop. From the article: The malfunction had been caused by a snapped “hoist rope,” or elevator cable, Maloney said. Other cables were still attached, keeping the elevator from plummeting to the floor.

nabla9 8y ago
Elevators don't go into free-fall even if all the cables are cut at once. The safety chain is just one of the two or three safety measures. The clack-clack-clack sound they reported was probably safety clamps attached to the rails. When the speed of the elevator exceeds some limit they start automatically breaking.
elhudy 8y ago
I was under the impression that the way elevators are designed, it's physically impossible for them to free fall upon failure. Source: documentary on the first elevators
- jsiepkes 8y ago
  There are indeed a whole bunch of security features which prevent a lift from free-falling. However there is another risk of it flying up and slamming into the ceiling for most types of lifts. For that kind of malfunction there is often no safe guard. A lot of lifts are of the type where they use a large weight which is about half the weight of the maximum load capacity of the lift. This weight is used as a contra weight and hangs in the elevator shaft (so it goes down if the lift goes up). If the brakes in the engine on top of the lift shaft fail there is nothing stopping the contra weight and the lift will fly up. This is a YouTube video of that happening: https://youtu.be/Ys0rDAxdd-g https://youtu.be/Ys0rDAxdd-g (warning its not graphic but obviously a disturbing thing to see)
  - SmellyGeekBoy 8y ago
    Why wouldn't the counterweight also have its own emergency braking system? Seems like an obvious oversight.
    - jsiepkes 8y ago
      A free fall safe guard is often mandated by law / regulation. A "shoot up slam into ceiling safe guard" is not. That makes it simply a cost thing. Since most people don't know about this risk and there aren't many accidents there is simply too little incentive.
      - zhte415 8y ago
        I think the parent means why not have a safety mechanism stopping the counterweight from falling? That would stop the lift shooting up.
        isostatic 8y ago
        Because it costs money and isn't mandated by pesky regulations.
        jsiepkes 8y ago
        My answer also meant to address that :-). I meant: There are plenty of technical ways to implement it (and the parent proposes a good one) but its not mandatory to do so, it costs money, and therefore its simply not implemented most of the time.
      - aurelwu 8y ago
        in the European Union, nowadays, it is required to have a safeguard for "shooting up" as well[0]. If I recall correctly for quite some time it wasn't though. My Father who works in the elevator industry told me that in the GDR (German Democratic Republic) it was already mandatory but after reunification for some years Germany had more lax regulations til catching up again. [0] https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:31995L0016&from=DE https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CEL... (See Annex I , 3.2)
  - svdree 8y ago
    Back in university I had a side job as a security guard in an office building, when this happened. Someone took the cargo elevator, which was built to carry a higher load than the regular elevators, so it had a massive counter weight. The thing slammed into the ceiling with a bang that could be heard through the entire building, and the damage was quite extensive. Took a while for the guy to calm down as well.
craftyguy 8y ago
The title says nothing about free fall or injuries, you did.

nabla9 8y ago

Elevators don't go into free-fall even if all the cables are cut at once. The safety chain is just one of the two or three safety measures. The clack-clack-clack sound they reported was probably safety clamps attached to the rails. When the speed of the elevator exceeds some limit they start automatically breaking.

elhudy 8y ago

I was under the impression that the way elevators are designed, it's physically impossible for them to free fall upon failure. Source: documentary on the first elevators

jsiepkes 8y ago
There are indeed a whole bunch of security features which prevent a lift from free-falling. However there is another risk of it flying up and slamming into the ceiling for most types of lifts. For that kind of malfunction there is often no safe guard. A lot of lifts are of the type where they use a large weight which is about half the weight of the maximum load capacity of the lift. This weight is used as a contra weight and hangs in the elevator shaft (so it goes down if the lift goes up). If the brakes in the engine on top of the lift shaft fail there is nothing stopping the contra weight and the lift will fly up. This is a YouTube video of that happening: https://youtu.be/Ys0rDAxdd-g https://youtu.be/Ys0rDAxdd-g (warning its not graphic but obviously a disturbing thing to see)
- SmellyGeekBoy 8y ago
  Why wouldn't the counterweight also have its own emergency braking system? Seems like an obvious oversight.
  - jsiepkes 8y ago
    A free fall safe guard is often mandated by law / regulation. A "shoot up slam into ceiling safe guard" is not. That makes it simply a cost thing. Since most people don't know about this risk and there aren't many accidents there is simply too little incentive.
    - zhte415 8y ago
      I think the parent means why not have a safety mechanism stopping the counterweight from falling? That would stop the lift shooting up.
      - isostatic 8y ago
        Because it costs money and isn't mandated by pesky regulations.
      - jsiepkes 8y ago
        My answer also meant to address that :-). I meant: There are plenty of technical ways to implement it (and the parent proposes a good one) but its not mandatory to do so, it costs money, and therefore its simply not implemented most of the time.
    - aurelwu 8y ago
      in the European Union, nowadays, it is required to have a safeguard for "shooting up" as well[0]. If I recall correctly for quite some time it wasn't though. My Father who works in the elevator industry told me that in the GDR (German Democratic Republic) it was already mandatory but after reunification for some years Germany had more lax regulations til catching up again. [0] https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:31995L0016&from=DE https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CEL... (See Annex I , 3.2)
- svdree 8y ago
  Back in university I had a side job as a security guard in an office building, when this happened. Someone took the cargo elevator, which was built to carry a higher load than the regular elevators, so it had a massive counter weight. The thing slammed into the ceiling with a bang that could be heard through the entire building, and the damage was quite extensive. Took a while for the guy to calm down as well.

craftyguy 8y ago

The title says nothing about free fall or injuries, you did.