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Comment by smt88 | Hacker News Reader

This is also true of elevators. The vendors intentionally write awful code so that only they can fix it.

Used to work in the centre point tower on Tottenham Court Road.

The lifts had no buttons inside the car, your security tag would program in the floor, so you had to get in the right one otherwise you’d be stuffed.

There was a restaurant open to the public at the top, so in the evening the lifts would be full of forlorn diners trying to find their way out.

The computer would often crash and reboot mid journey - the lift would stop, the lights would go out and the screen would run through a boot sequence, before starting up again.

I once saw a technician tinker the system and he genuinely had a bunch of five inch floppy disks.

I live in central London in a 3-4 years old building (24 floors) and the elevators are truly a joke. Every 3-6 days they somehow get out of sync with which floor they are currently on, especially if you go first to -1, after that pretty much every floor will be wrong :) I always wonder who wrote it.

It's probably trouble with the sensors in combination with bad capacitors, which cause the motors to not accelerate the elevator at the rate which it is programmed to expect, so it doesn't quite exactly know where it is. Tldr it's glitchy.

I know a guy who built an elevator system single board computer to control it. The big problem was the power to the board - the motor turning on and off and the old electrical system made it very spiky, which would cause the computer to glitch. He built in a lot of self-checking in the computer, but it would still fail once a day or so. He eventually fixed that by having the computer just hardware reset itself regularly.

Was there any particular reason that the problem could not have been resolved through hardware since the hardware was a new development?(i.e. a UPS or better filtering?)

The customer refused to resolve the issues with the electric power. My friend did add lot of filtering, but said he'd reached a limit.

This is quite horrifying. I am not sure if the elevator ride will be the same again for me.

Other than the space shuttle, by measuring deaths vs distance traveled per person, the elevator is the safest form of transportation.

https://www.reddit.com/r/theydidthemath/comments/2qbjw2/requ... though I recommend reading more into it and doing your own math.

Isn't soyuz better than space shuttle on this metric?

Not if we account for the "lost cosmonaut" ;)

How bout deaths per person-trip? After all, you’re mainly going in circles.

The post you link actually states the opposite, that Elevators are more dangerous than all the other listed methods of travel except the Space Shuttle.

My building replaced its elevators last year, and one car still has an “activate Windows” overlay in the corner of the screen. A recent change to the floor selection wallpaper has somehow resulted in the button font in another car mysteriously reverting to Verdana.

All I can do is remind myself there’s a mechanical interlock to keep the car from free-falling.

Escalators have mechanical interlocks and they've been failing a lot recently. Time to take the stairs.

I've never seen a lift controlled by a touchscreen. Is there any way for blind people to use it?

There’s a secondary interface at wheelchair height with a Braille-equipped keypad where you can type in a floor.

Don't be horrified for your safety. The software controls where the empty elevator goes. Many of the safety features, like the brakes, are tested regularly under the law and separate from the technician/programmer's work.

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