ski lift malfunction in the Caucasus Mts.

[stevej37]

Amazing that the worst injury was a broken wrist.
Where were the safeguards to prevent this?

[A930Rocket]

I’m guessing there’s no emergency off switch. People were really flying off the machine.

[cstreit]

My guess is its freewheeling backwards from the weight of the people on the one side...

I'm shocked there was no brake or governer to stop that sort of thing...

[Cooper911SC]

Crazy scary!

I was on an escalator arriving at the Heathrow international terminal a decade ago... the walkway at the top was pretty full and people couldn’t exit the escalator!! Much yelling to move forward to any available space... it was definitely feeling like an oh ***** where am I gonna bail situation.

People pushed forward and the escalator eventually got shut off.

[hcoles]

I think in the US there is a requirement for an automatic reverse brake of some sort.

[FPB111]

Brake broke, folks go BANG!

[GG Allin]

Originally Posted by hcoles

I think in the US there is a requirement for an automatic reverse brake of some sort.

On another board someone posted a video of something similar happening at Devils Head in WI.

[hcoles]

Originally Posted by GG Allin

On another board someone posted a video of something similar happening at Devils Head in WI.

The lift is designed and built by Doppelmayr Caraventa, an Austrian company. The lift had a number of safety systems installed. So my post suggesting the lift was not a modern design was incorrect.

I found this on a Snowboard site.

Initial reports suggest that engine failure is the root cause of the incident, but it is unclear why the several safety mechanisms, including the emergency break did not prevent the terrifying roll back.

[hcoles]

After some reading on the subject it seems there is typically 3 mechanisms - not all automatic - that should prevent rollback. E.g. a large pin can be dropped to lock the bull wheel - something like putting a stick in bicycle spokes.
Years (many) ago I was at China Peak and saw a chair drop off the cable just after going around the bull wheel at the bottom. Two people were about to load on.
Things you never think can happen sometimes do. It is difficult to design something that will never fail. Reminds me of an X/Y stage system I worked with. If the software or motors somehow misbehaved the stage had knives that cut through the cables going to the motors.

[beepbeep]

weird. It seems to go backward at steady state. If you switch two phases on 3-phase motor, it will reverse rotation. Somebody must have done something really weird to make it happen.

[Mark Henry]

By looking at this the cause was likely a motor/gear box/coupler failure. Once it has no drag form the motor/gearbox it's pretty hard to stop, in fact it was the jamming of the chairs that stops the lift.
Start at 4:28 it looks very similar with the inability to stop the lift.

[widebody911]

Reminds me of this video

[beepbeep]

As I suspected, it seems that it was switched phases. Lift way fairly new Doppelmayer design with lot's of interlocks.

It seems that electricity went down so they drove it off a generator with wrong phasing, spinning it full speed backwards.

"“However, after the chairlift was stopped, the operator had to introduce specific sequence of procedures and after implementation of the certain actions, the operator had to switch the chairlift on to the diesel generator power and bring the tourist to the safe site where they would have left the chairlift."

Press Conference On Preliminary Report by Bureau Veritas

[stevej37]

Kinda like jump-starting your car with a too-large battery, while it's in gear!

[Tobra]

Friend of mine got hurt when a chair lift failed, broken ankle.

I remember when the tram at Squaw broke. Squaw Valley cable car disaster. That car had at least a few dozen people in it, if I remember right, and most of them lived. I was up there the next weekend they were open. Had to ride two lifts to gut up as high as the cable car took you. When it happened, a retired doctor was there, or more people almost certainly would have died. If that thing would have been packed, cable would have cut 100 people in half.

[john70t]

Originally Posted by Tobra

If that thing would have been packed, cable would have cut 100 people in half.

An EA-6B Prowler aircraft once cut one of those cables and returned to base.
https://en.wikipedia.org/wiki/Cavalese_cable_car_disaster_%281998%29