8 replies to this topic

[iceberg210]

The last couple of times I've gone to Snowbird it has been in the range of 10 to 20 degrees F. And during these days, at the beginning especially, on the old Doplmyear doubles (Little Cloud and Peruvian) they have been running them not at full capacity, every other chair or so, because as they say the rubber in the bullwheel is so cold and hard that the cable would slip under full load. This makes sense since rubber loses its elasticity and flexibility when cold. Thats why you use softer rubber tires in winter because regular tires get hard in the cold and won't grip the road. Just wondering if anyone else at the resorts have this problem and if its common and how to solve it. Thanks.

This post has been edited by iceberg210: 22 January 2006 - 11:27 AM

[chasl]

iceberg210, on Jan 22 2006, 02:25 PM, said:

The last couple of times I've gone to Snowbird it has been in the range of 10 to 20 degrees F. And during these days, at the beginning especially, on the old Doplmyear doubles (Little Cloud and Peruvian) they have been running them not at full capacity, every other chair or so, because as they say the rubber in the bullwheel is so cold and hard that the cable would slip under full load. This makes sense since rubber loses its elasticity and flexibility when cold. Thats why you use softer rubber tires in winter because regular tires get hard in the cold and won't grip the road. Just wondering if anyone else at the resorts have this problem and if its common and how to solve it. Thanks.

That is definitly not normal, while I have heard of this problem at mountains that have heavy morning frost on the haul ropes, this is normally a temporary problem.
Some questions have to be asked.
First have the haul ropes slipped like this from day one? I would doubt it.
How old are the lifts?
Do the systems have a mass CWT? This can have potential problms over time, especially if it has extra blocks, can be checked with a load cell.
Do the systems have hydraulic tensioning? Definite problems if someone has changed the pressures.
Has the maint department changed the type or viscosity of the hydraulic oil?
Has the management changed suppliers for the bullwheel liners to someone other than Doppelmayr?
There are many systems out there that have aluminum or hard poly liners and do not have a slipping problem.
Does the maint department lube the rope during the operating season? this I would Highly doubt, if it was an oil problem the maint department should have corrected it by now.
I would have to believe that the tension system is not correct.

[liftmech]

I's have to agree. THe only time we have any problems with rubber components is when the belts in upper-mountain lifts get frosted over at night; this is also a temporary problem as the frost disappears once the lift has been run for a bit.

[iceberg210]

I didn't think it was an ussuall accurance. Unfortunetly I don't know of the reasons behind other then what they told me, also I don't know their matnience records. Its pretty odd but if its a matnience thing then I wouldn't put it past Snowbird with all their matnience problems lately.

[Allan]

We do this on Motherlode when ice builds up between the rope and the liner because it can't quite pull the 20,000 pounds (or so) of people up the hill without a jerky ride... we hoped a new liner would take care of it, but it didn't. We also try and clean the ice out with a pry bar at the same time.

[aug]

Allan, on Jan 22 2006, 05:57 PM, said:

We do this on Motherlode when ice builds up between the rope and the liner because it can't quite pull the 20,000 pounds (or so) of people up the hill without a jerky ride... we hoped a new liner would take care of it, but it didn't. We also try and clean the ice out with a pry bar at the same time.

most lifts have an ice scraper to prevent this . it also acts a a reference point if the bullwheel moves for some reason . i adjust ours as close as i can get it to the bw liner without scraping the bw liner.

[Allan]

Ours has a scraper - but this ice is more of a film that's really not that thick. It has to be perfect weather conditions (that don't happen that often). However maybe I'll have a look at the scraper when I get back to work after days off.

[ceo]

Someone on the SKIVT-L list some time ago spoke of being at Killington on a really cold day, and they were loading every other carrier on the Bear Mountain chair (a mid-80s Yan fixed-grip quad, top drive/bottom tension). The liftie's explanation was that running the lift at full capacity when it was that cold could cause deropements. I couldn't think of how that would happen, unless maybe the thermal contraction of the rope caused the tension carriage to hit the front stops, and the resulting higher tension in the rope pulled the sheave trains out of alignment. But that doesn't sound right either.

[Lift Dinosaur]

ceo, on Jan 23 2006, 12:54 PM, said:

Someone on the SKIVT-L list some time ago spoke of being at Killington on a really cold day, and they were loading every other carrier on the Bear Mountain chair (a mid-80s Yan fixed-grip quad, top drive/bottom tension). The liftie's explanation was that running the lift at full capacity when it was that cold could cause deropements. I couldn't think of how that would happen, unless maybe the thermal contraction of the rope caused the tension carriage to hit the front stops, and the resulting higher tension in the rope pulled the sheave trains out of alignment. But that doesn't sound right either.

Doesn't make much sense, but then you have to consider the source!