81 replies to this topic

[seilbahnbilder.ch]

Quote

Polar X grips

What kind of grips are these?

In Spain there is still a NOT retrofitted Yan HSQ in operation!
http://www.remontees...rtage-1057.html

This post has been edited by seilbahnbilder.ch: 06 July 2009 - 11:40 AM

[Lift Kid]

Quote

In Spain there is still a NOT retrofitted Yan HSQ in operation!
http://www.remontees...rtage-1057.html

Please remember that climate had a lot to do with the Quicksilver accident. The climate at that ski area in Spain could be very different from Canada. I am not entirely familiar with the climate in that area, but it is probable that it isn't affecting the marshmallow springs as severely as Canada's climate. Also, remember that there were many of these lifts operating all over North America and elsewhere at the time of the Quicksilver incident, none of which failed catastrophically like Quicksilver.

[SkiBachelor]

Lift Kid, on 06 July 2009 - 01:10 PM, said:

Please remember that climate had a lot to do with the Quicksilver accident. The climate at that ski area in Spain could be very different from Canada. I am not entirely familiar with the climate in that area, but it is probable that it isn't affecting the marshmallow springs as severely as Canada's climate. Also, remember that there were many of these lifts operating all over North America and elsewhere at the time of the Quicksilver incident, none of which failed catastrophically like Quicksilver.

The Quicksilver Express at Whistler was the only YAN HSQ with the Type 11 grip and had a very steep section. However, there were never any report incidents involving the Type 7 grip, which is what the other YAN HSQs used.

[Lift Kid]

What were the differences between the two grips? What made the 11 so different from the 7?

[skiersage]

Lift Kid, on 06 July 2009 - 01:10 PM, said:

Please remember that climate had a lot to do with the Quicksilver accident.

Climate had nothing to do with it. Here is a list of factors that contributed to the accident:
The failed carrier was on the steepest section of the lift.
The accident occurred on the down line as oppose to the up line, this brings gravity into the equation.
The carrier had passengers on it which added mass.
The lift was outfitted with bubbles which means more weight.
The accident occurred during an abrupt stop.
The marshmallow springs used didn't provide as much force as the metal springs used by other lift companies.

Another thing to keep in mind is Newton's first law of motion, which is: "Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it." Similarly when the lift came to a sudden stop, the carriers naturally wanted to continue moving forward. In this case the forward momentum of the carriers plus the pull of gravity was enough to overcome the force of the grip. This caused the grip to slide down the cable and thus the quicksilver accident occurred.

Lift Kid, on 06 July 2009 - 06:16 PM, said:

What were the differences between the two grips? What made the 11 so different from the 7?

Yan type 11
Here is a picture of a grip from the quicksilver lift.
compare this with the yan type 7

[Lift Kid]

I recall reading that the climate made the rubber springs brittle, therefore even less force.

[skier2]

Lift Kid, on 06 July 2009 - 07:44 PM, said:

I recall reading that the climate made the rubber springs brittle, therefore even less force.

Yes, I have read the official accident report several times and recall distinctly the severe and abrupt changes in temperature at Whistler as being a contributing factor to the weakness of the grip force. Still, this is only a fraction of the cause, as the lift also had too steep a profile for the design and a faulty e-stop alarm.

[skiersage]

Lift Kid, on 06 July 2009 - 07:44 PM, said:

I recall reading that the climate made the rubber springs brittle, therefore even less force.

Colder temperatures make all materials less resilient. I would think that all spring powered chair grips lose force as the temps drop. As to whether temperature has a profound effect on rubber I don't know. But one thing I know was stated was that the marshmallow springs had less grip force to begin with.

[seilbahnbilder.ch]

Thanks for the very interessting information!

Is the chairlift in Spain equipped with Yan 7 grips? And what is the siginficant difference between Yan 7 and 11? I can't see a huge difference?!

[SkiBachelor]

The Type 11 was designed for heavier loads, just like the Doppelmayr DT-104 vs. DT-106.

[liftmech]

seilbahnbilder.ch, on 06 July 2009 - 11:39 AM, said:

What kind of grips are these?

In Spain there is still a NOT retrofitted Yan HSQ in operation!
http://www.remontees...rtage-1057.html

You mean 'Pol-X', not Polar-X. That refers to a company that redesigned the YAN-7 for more reliable use. They addressed the issues which contributed to the originals being pulled from service, like the rubber marshmallow springs and the rope size inserts. Ultimately the redesigned grips were used only on two? installations, both in Alberta. Every other L/E detach in North America was retrofitted by Doppelmayr or Poma, or replaced entirely.

[mikest2]

liftmech, on 10 July 2009 - 05:39 AM, said:

You mean 'Pol-X', not Polar-X. That refers to a company that redesigned the YAN-7 for more reliable use. They addressed the issues which contributed to the originals being pulled from service, like the rubber marshmallow springs and the rope size inserts. Ultimately the redesigned grips were used only on two? installations, both in Alberta. Every other L/E detach in North America was retrofitted by Doppelmayr or Poma, or replaced entirely.

Silver Star's two Yans were also retrofitted at the same time as Lake Louise's

[liftmech]

Ah, forgot about those ones. Are they still there? I seem to recall one of them had a heavy-side-only midstation.

[mikest2]

liftmech, on 18 July 2009 - 05:34 AM, said:

Ah, forgot about those ones. Are they still there? I seem to recall one of them had a heavy-side-only midstation.

No, they were replaced when Silver Star was bought by our group.

[skiersage]

My Linkhttp://www.polxwest.com/YnGrip.htm
For reference, link to Pol-X chair grip web page.

[Skier123]

KZ, on 19 November 2003 - 08:49 AM, said:

Yep, and becasue of the accidents and lawsuits, Lift Engineering went out of business, and now there are only 2 lift makers. Kinda sad if you ask me

Lift Engineering should've just stuck with fixed grips.

[Emax]

Skier123, on 26 August 2009 - 05:39 AM, said:

Lift Engineering should've just stuck with fixed grips.

Amen

[mthornton]

Quoting Artur Doppelmayr, 1997

I would have taken his ideas, but then, I would send them to my engineers.

[EagleAce]

Skier123, on 26 August 2009 - 05:39 AM, said:

Lift Engineering should've just stuck with fixed grips.

Amen X2! I've always liked the simplicity of his fixed-grips.

[Skier123]

Am I the only one who can no longer see the pictures on this post?