That's an odd accident... From the picture and description it looks like multiple chairs collapsed into each other, but that is not a detachable high-speed lift. If one of the chairs somehow snagged on a lift tower mount I guess there's enough force in the cable that the cable might come loose from the chair mount and keep going? I hope the injuries weren't serious and that everyone is OK.
Some more stories about this incident:
Ski Lift Malfunction Leaves 100 People Stranded on Mountain - Time Magazine
Trouble at Tussey Mountain: Minor injuries reported after chairlift malfunction - The Penn State Daily Collegian
And I just published a story about this accident here.
So good that no one was killed. It will be interesting to see what the investigation will show. All lifts in PA are suppose to be inspected yearly by a state agency. Reports say the lift passed inspection.
I would guess that they take the chairs off over the summer for maintenance. Perhaps when they were putting them back on, someone didn't tighten them back onto the cable properly? I have very little knowledge of how those things work but the car to cable connection has always made me wonder about the stresses involved at that point. Had to be very scary and hopefully there were no serious injuries. In the end, our safety as skiers is left in the hands of the maintenance crews and any inspectors. Maybe this will be a wake-up call to other resorts to double or triple check their lifts as the season gets under way...
Sure hope these folks aren't hurt too bad. I cringe every time I get on Powder Monkey lift. That thing just looks and feels bad to me.
if you look at the cable you should see paint marks in front of each grip. that marks the starting point for each season. the grips slowly move down the cable during the season of use. the spacing should be almost the same for every chair.
the grips are meant to slide in the event of a disrail of the cable so you don't get dragged over some tower structure.
should be moved and retorqued each summer. some one didn't get the torque right.
I know that in PA chairs are removed from the cable, maybe 50% as required by maintenance and inspection. I don't know if it is a state rule or manufacturer's suggested practice. In summer at the PA resorts, I always see a number of chairs removed and on the ground. I know that each lift must pass a state inspection but I don't think they check torque on each grip. So happy there are no fatalities, maybe even no season ending injuries. My best to all the victims, speedy recovery.
I feel sorry for what happened especially for the guests who experienced it. Regarding maintenance & inspection a ropeway, it is clearly outlined by the manufacturer, by ANSI B77.1 and NFPA 101. The various ropeway-specific requirement's results in different rope constructions. There are many reasons way such an incident can happen. I dont even want to speculate why! Two items I believe needs to be checked out: grip and rope, since it is a simple fix-grip lift. I am also interested regarding the rope. In many US juristictions the visual inspection of the rope is part of it but not an electronomagnetic induction testing, which could detect loosing of wire lay or starnd lay. Especially since the chaillift stoped. The rope and grip are under a high pressure in such events. As we know many smaller resort use fix-grip lifts for cost reasons. The ropeway is still one of the safest transportation systems but with aging infrastructors and outeded inspection codes I believe we will see more closing of local hils since the cost will go up to update our systems..
In many cases the lifts are so old the manufacturer is sold off or out of business.