Page 1 of 1

Final Report on the Dec 2016 Solvista Chair accident

PostPosted: Thu May 11, 2017 8:36 pm
by EMSC
The final report about the chairlift incident that killed a 40 year old woman is out. It's long but contains several interesting items and seems to be a confluence of events that would be difficult to duplicate. Multiple recommendations including adding 'black box' data gathering to ski lifts.

The key quotes perhaps being:
“No one on the investigative team has ever witnessed or heard of a similar event”
“Likewise, literature does not describe such an event.”

Denver Post Article
http://www.denverpost.com/2017/05/11/ski-granby-ranch-ski-lift-death-final-report/


Final Report from the Colorado Passenger Tramway Safety Board
https://drive.google.com/file/d/0B-K5DhxXxJZbQUhTaDJOUzRBNU0/view?usp=sharing

Re: Final Report on the Dec 2016 Solvista Chair accident

PostPosted: Mon May 15, 2017 3:19 am
by q
It seems strange that a change in speed would result in a side to side swing to that extent. Also strange that if it was as bad as that in terms of slowing/speeding that it wasn't damn obvious to the resort that the lift had something technically wrong with it.

Re: Final Report on the Dec 2016 Solvista Chair accident

PostPosted: Mon May 15, 2017 11:21 am
by EMSC
q wrote:It seems strange that a change in speed would result in a side to side swing to that extent. Also strange that if it was as bad as that in terms of slowing/speeding that it wasn't damn obvious to the resort that the lift had something technically wrong with it.


I think the implication in the report is that somehow the start/stops/speed changes that were input by the operators hit upon the natural frequency of the haul rope/tower system with highly unexpected line behavior - eg think Tacoma Narrows Bridge behavior: wind in one direction caused unbelievable movement in other directions until destruction of the bridge.

Re: Final Report on the Dec 2016 Solvista Chair accident

PostPosted: Tue May 16, 2017 9:41 am
by EMSC
Colorado chairlift fall that killed Texas mom so improbable was “like getting hit by lightning inside a building”
http://www.denverpost.com/2017/05/15/granby-ranch-chairlift-death-improbable/