6 replies to this topic

[Powdr]

I don't know if this has been discussed before, but I was riding the Cabriolet for the 4th of July celebration at the Canyons (BTW - great show, Canyons!) and noticed that it has a slight angle change about half way up. Even though the lower terminal to top terminal is a straight shot, they had to put the some towers into pre-existing bunkers on the median of the access road and I think they had no choice but put a slight angle into it to make it fit.

What is interesting is that, instead of using some sort of angle station, they just used inclined sheaves to offset the slight lateral force caused as the rope changes angle. I was wondering if anyone else has seen this kind of set-up, and also how much angle change you could achieve, given that eventually the rope would skip off if too much angle was used.

Sorry, no pictures. You'll have to take my word for it.

Powdr

[SkiBachelor]

Yes, we have talked about this issue in the past, but this forum has crashed many times since that thread was started. Anyway, I think the reason why the Cabriolet has that turn in it is because there is a section where if the Cabriolet was on a straight shot, a tower would be on private property. So by angling the lift line, The Canyons was able to install the Cabriolet, keeping everyone happy.

[liftmech]

Powdr, on Jul 9 2004, 10:57 AM, said:

What is interesting is that, instead of using some sort of angle station, they just used inclined sheaves to offset the slight lateral force caused as the rope changes angle. I was wondering if anyone else has seen this kind of set-up, and also how much angle change you could achieve, given that eventually the rope would skip off if too much angle was used.

Sorry, no pictures. You'll have to take my word for it.

Powdr
<{POST_SNAPBACK}>

I'm not certain of the angle change maximum, but it is related to the amount of longitudinal deflection the sheaves impart as well. In other words, a highly loaded depression tower is a good candidate for an angular deflection setup, given that the preexisting load will hold the rope in the sheaves. I've seen photos of surface lifts with this setup, and I believe Breck engineered an angular deflection on their Chair 5 a while back. They didn't have enough load on an existing depression tower, so they added a support tower on either side to achieve a more solid capture in the grooves of the depression sheaves.

[Powdr]

l wonder if start & stops are a problem since the rope increases/decreases tension on alternating sides of the tower doing these sequences. Also, if downward loading is required on the tower that has the angle, then how did they string the rope past the tower during construction before downward tension was applied?

Powdr

[liftmech]

Same as a normal rope installation- the rope is pulled around by a strawline (usually less than half the diameter of the haul rope for ease of installation) and the tension is applied by the splice rig. When a rope is newly installed, it has no tension until the splice is finished, and even then the tension is low.

[iceberg210]

The Baldy Express Lift at Snowbird has those kind of sheaves and when I asked Bob Boner about it and he said that instead of doing a NEPA study on the public land they could keep it all on private land with that slight dogleg. He also said it ended up saving them money due to the NEPA fees as well as a lot of time.

[floridaskier]

How much of an angle change is the Baldy lift?