EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: OE2WHP on March 20, 2018, 10:24:03 am
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https://www.youtube.com/watch?v=XBSYJeODukg (https://www.youtube.com/watch?v=XBSYJeODukg)
“Jump, jump” that’s what people were screaming to warn skiers of trouble ahead. A ski lift malfunctioned at the Gudauri resort in the country of Georgia. People were forced to jump, others were thrown off their seats. At least eight people were injured, no one died. WARNING: some people may find this video disturbing.
What really bugs me
1. The guy woh is filming instead of doing anything helpful....
2. Noone had the idea to push the emergency shut down button.
3. Why the hell did the system not stop on its own?
I mean, we don't have any details what the owner or the operators did to the system but maybe they tampered with the security systems of the lift.
I am pretty sure that the manufacturer of this lift, a company from my home country (https://www.doppelmayr.com/en/ (https://www.doppelmayr.com/en/)), one of the most reknown manufacturers of ski-lifts would have some failure detection emergency shutdown system. They know their stuff.
Also, it is the first accident of this kind that I am aware of
What could have gone wrong to make the lift go into "fast rewind mode"??
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Only speculating as I don't know the construction of these lifts.
If the large wheel is driven from a chain coupled to the motor/reduction-box to create
additional gear reduction (small sprocket to large sprocket, not unlikely) and the brakes are only at the back of motor (easier to manage).
Then if the chain would break (they do require maintenance..) the weight of the passengers alone
good make it spin this fast.
What ever the cause, a sad event either way.
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You see people getting mad about other people not helping regularly, but often it's a matter of not being able to do much. Getting hurt isnt helping anyone and other than pulling people away from the lift, there's not much that can be done. If you don't know what to do, it's best to simply stay out of the way.
My information is far from reliable, but I've heard the lift lost power. This meant the lift started moving backwards due to the weight of the people in it, with the result you see. Judging by how the lift did stop in the end, someone did push the emergency brake. It seems a few people were actively trying to figure out how to do that, as the guy dressed in red walking into the shot at 0:32 is clearly trying to communicate with someone about what to do.
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What really bugs me
1. The guy woh is filming instead of doing anything helpful....
Recording an incident like this can be very useful for investigating what happenned.
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What really bugs me
1. The guy woh is filming instead of doing anything helpful....
Recording an incident like this can be very useful for investigating what happenned.
The journalist's demeanour.
Edit:
Shit. I meant dilemma
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The journalist's demeanour.
Not really. You don't want an incident happening, but you certainly don't want an incident to happen again.
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What really bugs me
1. The guy woh is filming instead of doing anything helpful....
Recording an incident like this can be very useful for investigating what happenned.
This.
Besides there's little a random passer-by could do to help.
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I can imagine pushing an electronic emergency button doesn't do much when the chain broke and the whole system is freewheeling?
From the footage it is clear the lift is running on gravity of the people still in it; that's why it stops in the end
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The same event from another angle, in this one it appears that the camera man is in fact a hero, seems he was the one yelling at people to jump and he also assisted somebody who was stuck in the debris.
https://www.youtube.com/watch?v=BGLTtu-RUvo (https://www.youtube.com/watch?v=BGLTtu-RUvo)
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It's also worth remembering that tugging on people who just were in a traumatic event can make things worse, much worse. When there's the potential of skull or spinal injuries, you need to be careful.
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What really bugs me
1. The guy woh is filming instead of doing anything helpful....
I didn't actually watch the videos so this is just a general comment. But there days many skiers may have an action camera attached to their helmets and already filming. So to film something like this it can be enough to just be in the area and be looking in that direction.
3. Why the hell did the system not stop on its own?
My guess would be that the lift was freewheeling and for some reason there was a brake failure. I'd imagine that this kind system should have automatic brakes for this kind situation but those weren't working for some reason.
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I can imagine pushing an electronic emergency button doesn't do much when the chain broke and the whole system is freewheeling?
From the footage it is clear the lift is running on gravity of the people still in it; that's why it stops in the end
Good point, but isn't that a failure mode that should be pretty obvious and be chatched during FMEA?
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Yes, so probably the red button just (only) stops/blocks the motor
I assume these systems have an independant mechanical auto-brake system (which failed obviously)
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It's too late for me not to look like a goose... But I mistyped earlier.
It's the journalist's dilemma. Get involved, or report the story. I understand it's a particular issue for cameramen. I don't know what their code of conduct says about it, maybe there's one hanging around who could chime in.
Also, obviously, not everyone with a camera is an actual journalist...
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You see people getting mad about other people not helping regularly, but often it's a matter of not being able to do much. Getting hurt isnt helping anyone and other than pulling people away from the lift, there's not much that can be done. If you don't know what to do, it's best to simply stay out of the way.
I agree.
My information is far from reliable, but I've heard the lift lost power. This meant the lift started moving backwards due to the weight of the people in it, with the result you see. Judging by how the lift did stop in the end, someone did push the emergency brake. It seems a few people were actively trying to figure out how to do that, as the guy dressed in red walking into the shot at 0:32 is clearly trying to communicate with someone about what to do.
There should be a brake, which activates when the power is lost. That's pretty standard on any system which can keep moving and present a hazard, due to power failure.
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It's also worth remembering that tugging on people who just were in a traumatic event can make things worse, much worse. When there's the potential of skull or spinal injuries, you need to be careful.
Having other people land on them isn't ideal either. In this case just pick the least worse.
Cable cars often have the motor at the top, the bottom station might have been meaningless in this situation.
Looking at the lack of significant building, it might have been the case here.
https://www.doppelmayr.com/en/components/custom-drive-solutions/ (https://www.doppelmayr.com/en/components/custom-drive-solutions/)
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I dont know where I was read about that in the Lift System the have some Anti Tamper thing include to prevent it from Copy it.
So some people say that the Company would safe cost and try to repair and maintain there stuff there own and some anti tamper thing was kicking in. To get the Lift back to work the might have do some Russian style stuff to get it run and that used an go arround of some safety stuff.
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This is on the manuacturers site:
Accident Gudauri, Georgia – Friday 16. 3. 2018
Pressinformation, 18th March 2018
We hope that the injured persons are getting better. Get well soon. This is the most important point at the moment.
The cause of the accident is not known yet. But we can state the following facts:
The lift is a 4-seater fixed grip chairlift and was built by Doppelmayr in 2007.
Doppelmayr specialists arrived in Gudauri on Saturday morning.
Meanwhile (Sunday afternoon) first site inspections together with authorities and independent test institut were possible.
We support authorities and our customer extensively.
First official results are not expected before the beginning of next week.
Presumptions and hypotheses regarding the potential cause(s) would be unprofessional at this point.
As soon as we have more facts and approval of the authorities we will inform accordingly.
http://newsroom.doppelmayr.com/en/doppelmayr/news/accident-gudauri-georgia-friday-16-3-2018/ (http://newsroom.doppelmayr.com/en/doppelmayr/news/accident-gudauri-georgia-friday-16-3-2018/)
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Can someone with a Youtube account please contact AvE to look into it :clap:
so we can find out what really went wrong
before it gets forgotten or swept under the snow ::)
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What really bugs me
1. The guy woh is filming instead of doing anything helpful....
2. Noone had the idea to push the emergency shut down button.
3. Why the hell did the system not stop on its own?
1. What’s he supposed to do, exactly? And why him and not the dozens of other bystanders?
2. What makes you think nobody thought to do that? The thing was going backwards, because the motor that drives it forwards was clearly either off or mechanically disconnected, AND the braking mechanism obviously failed.
3. Why the emergency braking system failed is, of course, the million dollar question.
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Long story short, operator error. (preliminar result from investigation).
http://www.economy.ge/index.php?page=news&nw=645&s=preskonferencia-gudauris-incidentis-shesaxeb-biuro-veritasis-pirvelad-daskvnaze&lang=en (http://www.economy.ge/index.php?page=news&nw=645&s=preskonferencia-gudauris-incidentis-shesaxeb-biuro-veritasis-pirvelad-daskvnaze&lang=en)
Bureau Veritas expert arrived to Georgia upon the invitation of the Ministry of Economy in order to provide technical inspection aiming at revealing causes of the incident on 16 March in Gudauri. Today, preliminary report prepared by the Bureau Veritas is already available.
Bureau Veritas experts concluded that there really was electricity failure, which led to the operation failure of the chairlift.
“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.
Unfortunately, according to the current conclusion, the operator made a mistake. The combination of the actions that he should have had carried out were not implemented in compliance with the relevant instructions – it was a human error.
Preliminary report will be transferred to the Ministry of Internal Affairs, which will continues investigation and accordingly, will charge the liable persons in compliance with the existing legislation.
In our turn, we distracted the operator rom his duties. In addition, two citizens addressed me with the request to suspend their offices. These are the Deputy Director of the Mountain Resort Development Company, Irakli Chirakadze and the Head of Gudauri Mountain Management Department, Kote Kadagidze. These two people also realize their responsibility, they feel moral responsibility and are keen to stop their authority. The Conclusion is as follows: safety rules were fully introduced but there was a human error factor,” – Dimitry Kumsishvili said.
According to the conclusion, the chairlift was provided with timely scheduled inspections and was in a perfect technical order. This was double-checked as well. At the same time, complete technical inspection was performed on December 22, 2017.
Mountain Resorts Development Company of the Ministry of Economy and Sustainable Development of Georgia is in active cooperation with numerous international organizations and companies in order to retrain its employees. During the past two years, technical personnel of the chairlifts of the resorts of Gudaur, Bakuriani, Svaneti and Goderdzi were actively involved in the training cources. In 2017, technical personnel were trained in a factory at the head office of the Dopplerier in Austria, which provided training in electric cable systems, safety, engines, hydraulics and other details. At the same time, important training was carried out for the technical personnel before the winter season 2017/2018 was opened. Training under the EU TAIEX program provided teaching by the French experts on safe operation of the chairlifts. In January 2018, the training conducted by the French ropeway company Poma was aimed at inspection and repair of the chairlift safety equipment and retraining of the chairlift staff.
Skiing resorts are equipped with the chairlifts produced by the world-known companies including the Austrian company Doppelmayr, which is the is the leader in the quality, technology and chairlift manufacturing. At this point, the Doppelmayr has installed 14 800 chairlifts in 92 countries. Doppelmayr has been actively cooperating with Georgia since 1986. There are 15 chairlifts installed in mountain ski resorts (6 in Gudauri, 6 in Bakuriani, 1 in Svaneti, 2 in Goderdzi) Innovative transport system is consistently in line with the world's advanced standards. The Doppelmayr also provided the construction of the Tbilisi Funicular and the cableway in Batumi.
Taking into account these facts, we can say that the March 16 accident in Gudauri was a single standing exception.
Expert conclusion by the Bureau Veritas will serve as a basis for the decision issued by the Ministry of Economy and Sustainable Development of Georgia regarding the incident in Gudauri. We will provide the final decision upon the results of the official investigation. In addition, the investigation will be continue by the Ministry of Internal Affairs, and the relevant results will be known later. Prior to the completion of the investigation, the authority will be suspended to the operator being on duty when the chairlift accident occurred. Issues related to charging of other liable persons will be detailed after completion of the official investigation.
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They can deem this failure as operator error all they want but where on a power outage people are openly put at risk and a sole person is then required to conduct a possibly non routine or rarely practiced sequence to start and switch over to generator power I would deem a serious design flaw or engineering failure.
They should have incorporated some type of fail safe mechanism into the design to remove any risk of a runaway where on a power outage a mechanical braking system would be engaged perhaps with a manual lever to permit a controlled evacuation of people, elevators incorporate such mechanical braking systems why didn't this dangerous chair lift ?.
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How hard can it be? :-//
Power drops out,
big relay drops out,
no power,
everyone in :wtf: mode
Someone restarts the machine or calls for rescue
Too easy... :clap:
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I heard enough Story about people who are bad or non trained.
The get told "push here for Start and Stop and if something happened here is a flyer what to do." :palm:
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Doesn't sound plausible to me. Sounds more like a pawn sacrifice. These lifts do not go into free spin, taking lifes at risk when power drops out. They wouldn't even get an operating license here if this would be the case. I still think someone tampered with some sort of security mechanism.
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Expected. (Formal) communist way of doing things. Cover up issues with the "system", and blame on a pawn.
That's unlikely due to an independent investigatory bureau being involved. You could argue the manufacturer Doppelmayr is served by sweeping a problem under the rug, but the customer's trust is very important for a lift manufacturer and if people smell a cover-up it could seriously hurt the business. Customers aren't stupid and it's better to have a good explanation that doesn't have a funny smell, even it it means admitting there's been a technical error. Not to mention it's a Austrian - Swiss company, people known for their tendency to be thorough.
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I'm not saying the equipment manufacture tried to hide things, nor I'm trying to say the operator is not at fault.
What I think is something in their maintenance went wrong, and not the company that makes the gears, but the company runs the business, tried to hide something.
Another possibility is that the company that runs the park hired substandard operators and safety personnel to save money, and when shit hit fans, they blame a single operator rather than the HR system.
That's all possible, yet the involvement of both an independent bureau and the manufacturer make it unlikely that will fly. Doppelmayr probably couldn't care less about the company that runs or maintains the lift. It just needs to the world to know their lifts are safe. The same applies to the bureau. If you let someone dictate the outcome of your investigation, your days as an independent bureau are over.
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This is crazy.
If the switchover from a failed mains to diesel backup requires a sequence of manual steps then this sequence should be interlocked in such a way that a catastrophic failure like this should be impossible from a simple misstake.
Furthermore, a independent failsafe mechanism should be present that gauges the speed/direction and applies an emergency brake if outside of limits. This could be a simple centrifugal device that releases a spring loaded brake. Automatic brakes like this could be mounted in many (or all) towers to help with cable breaks, damaged towers and other failure modes.
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listen to the sound of the video, roll gears as if without resistance and accelerating. It means that the gearbox is separated from the engine (or the engine is off-duty and has a light-weight running), the reverse thrust is still accelerating. In my opinion, the safety brake did not work - like the elevator -
unbraked engine brake jaw closed, the engine's servo jaw brake opens when the engine is energized.