Chairlift rollback

Scary stuff

http://unofficialnetworks.com/2018/03/16/chairlift-malfunction-video/

When I was a liftie, probably the lift failure that mgt feared the most was a rollback. There's an emergency brake that's there as a last resort measure in event of a catastrophic failure. They told us if we hit the e-brake as soon as the rollback started, it would stop it but if we hesitated at all, the weight of a loaded line plus gravity would be too much to stop and this would happen. This video is scary but instructive too. Early on you see one chairload bail as they get close to the ground and then you see how violently the people that try to ride it out are thrown. If you're ever in this situation, you need to get off before you go back around the bottom wheel

damn!

Yeah.  Sure as shit I’m jumping off if ever a chairlift I’m on starts rolling back.

I recall reading about a ski resort that did an intentional rollback with weights, etc. on a lift they were removing.  A real mess; no one knew exactly what would happen.  The end result was carnage like in this video.  I think a tower went over in their experiment.

D.B. Cooper wrote

I recall reading about a ski resort that did an intentional rollback with weights, etc. on a lift they were removing.  A real mess; no one knew exactly what would happen.  The end result was carnage like in this video.  I think a tower went over in their experiment.

Someone posted that on here a while back.

Man, that one person in the red who didn't manage to jump and got hurled up into the machinery . . .

One more thing to make sure the kids know.

Petronio

Petronio wrote

D.B. Cooper wrote

I recall reading about a ski resort that did an intentional rollback with weights, etc. on a lift they were removing.  A real mess; no one knew exactly what would happen.  The end result was carnage like in this video.  I think a tower went over in their experiment.

Someone posted that on here a while back.

Here it is:

Holy crapola

lesson to learn that you have to bail out

dif angle

I've always wondered what was available to actuate the E-brake in the event of a power outage. Seems to me if there was a power outage, unless there was a battery back up of some kind to run the controls (which could fail too) the E-brake won't work. I asked Snoloco about this and he said that the E brake is a normally closed mechanism that is actuated by a spring, and there is a hudraulic mechanism that opens the brake when the lift is running, and will automatically close when power is lost. Hard to imagine a spring that's strong enough to hold that massive thing back, but I guess it exists. My ropetow E-brake is the opposite. When the stop gate is tripped, or the engine is manually turned off there is an alectronic actuator that kicks in and engages the E-brake.

Here's the CNN article that is making the rounds in the U.S.  Been picked up by TV news in the flatlands in the midwest for some reason.  First hand account said the lift stopped and then rolled back very soon after.

https://www.cnn.com/2018/03/16/europe/georgia-ski-lift-accident-intl/index.html

Ethan Snow wrote

I've always wondered what was available to actuate the E-brake in the event of a power outage. Seems to me if there was a power outage, unless there was a battery back up of some kind to run the controls (which could fail too) the E-brake won't work. I asked Snoloco about this and he said that the E brake is a normally closed mechanism that is actuated by a spring, and there is a hudraulic mechanism that opens the brake when the lift is running, and will automatically close when power is lost. Hard to imagine a spring that's strong enough to hold that massive thing back, but I guess it exists. My ropetow E-brake is the opposite. When the stop gate is tripped, it the engine is manually turned off there is an alectronic actuator that kicks in and engages the E-brake.

I'm surprised that lifts aren't designed to be "Fail safe" = safe when normal operation fails.  E.g., rail brakes.  On a train, the brakes are kept off by air pressure.  If a line fails, the brakes go on and the train stops.  You would think a ski lift would be designed similarly, so that it is impossible for what happened here to happen at all.

Petronio

Most chairlifts do have fail safe brakes. Meaning that the hydraulic pressure hold the brake open and the brake is normally closed. I'm an idiot, and didn't even think of that until this thread existed.

Ethan is correct. That is how the e-brake works. It's pumped open by hydraulic pressure and hitting the button just releases the pressure so it clamps down on the bull wheel. If you hit iit by mistake, you have to call a mechanic to come and pump it back open again. Any time I experience a really long stop on a lift I wonder if the liftie hit the e-brake by accident. I was told that it was strong enough to stop a rollback before it built up too much speed but that I didn't have much time. Once it's rolling at the speed in that video, there's nothing to stop it.
So in this case, either the liftie didn't hit the e-brake in time, the e-brake failed or Georgia's standards are so much lower then the U.S. that this lift didn't have one.

Why not design it to remove human error?  If flywheel goes in reverse in excess of threshold speed, pressure to ebrake is cut.

Good question. I don't know. I asked questions like that when I was a liftie but nobody knew the answers. I also always wondered why not make the brake strong enough to stop a fully loaded line? Maybe newer lifts have better systems installed.

What happens if you don't have electricity?  The idea is the power source needs to be working to keep the brakes from locking down.

Scary AF. That lady in red got smashed.

Our summit chair here needs to be replaced so badly. I'm afraid it might do something like this one day. On powder days before our 6 pack we would sometimes lose power, run it off a diesel engine at half speed and load every other with two instead of three because of it's slippage.

What was slipping? Must have been linkage between the diesel and the bull wheel because if it wasn't slipping under normal conditions not sure what else it could be.

tjf1967 wrote

What happens if you don't have electricity?  The idea is the power source needs to be working to keep the brakes from locking down.

Exactly.  Most chairlift work like I described above with a failsafe mechanism. For my situation, it was easier to do it the way I did it, and with a rope tow it's not a big deal if you get a little rollback. Easy to let go.  

Ethan Snow wrote

What was slipping? Must have been linkage between the diesel and the bull wheel because if it wasn't slipping under normal conditions not sure what else it could be.

I have Know idea. I'm not a lift ninja like you and Sno are. My buddy Eli that worked with that lift for at least 10 years and now is a lift mechanic for Taos says it's all good but I still want a new lift.