70 replies to this topic

[Duck]

With lifts this long, what kind of extra precautions or engineering has to be done with regard to tensioning? Is it a bugger trying to connect the two ends of the rope? Does the tension station have to have an extra chunk of travel to accomodate the extreme length?

-Iain

[djspookman]

Duck, on Jun 1 2005, 10:50 AM, said:

With lifts this long, what kind of extra precautions or engineering has to be done with regard to tensioning?  Is it a bugger trying to connect the two ends of the rope?  Does the tension station have to have an extra chunk of travel to accomodate the extreme length?

-Iain
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I've wondered that myself Iain. That's a LOT of weight on there, plus it goes up and down 2 major ridges.

dave

[SkiBachelor]

Check out the Silver Mt. Gondola pictures. It's too big of a system for a hydraulic tension system.

http://skilifts.org/id-silvermt.htm

[ceo]

Jonni, on May 30 2005, 05:39 PM, said:

The weird thing about the whole set up is that driving south towards the resort you can see both sides of the ski area (Sugarbush North and Sugarbush South), and they are literally 2 miles away from each other. It's hard to believe that there is a lift that connects them.
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The Slide Brook Express exists because Sugarbush bought the former Glen Ellen ski area and turned it into Sugarbush North. They tried for a long time to get the permits to develop the Slide Brook watershed between them (which is Forest Service land, I'm pretty sure), and were denied due to environmental concerns. Before SBE went in, the areas were connected by a shuttle bus.

[Jonni]

Fortunately, ASC was able to get approval to build the Slide Brook Express to connect to the two areas, as long as the lift didn't intrude upon the conservation land. It's too bad they don't run it in the summer, as the ride is very very scenic, and gives an up close and personal view of the mountains. If it were to run in the summer, Sugarbush would also have to run the Gate House Express as an access lift to get to one end of the Slide Brook. Although, they might actually make some money if they charged, for instance $10-15 round trip. It could be set up so you ride up the Gate House lift, then ride the Slidebrook lift to one end and stay on the lift and ride back. Just my $0.02 worth.

As far as the Silver Mountain Gondola, here's the facts about the lift: http://www.silvermt.com/gondola.html. The counter weight is an older style block and cable weight. The counter weight alone weighs 55 tons!

[Duck]

SkiBachelor, on Jun 1 2005, 04:46 PM, said:

Check out the Silver Mt. Gondola pictures. It's too big of a system for a hydraulic tension system.

http://skilifts.org/id-silvermt.htm
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Man, that is one ugly system. :---:

-Iain

[liftmech]

Duck, on Jun 1 2005, 07:50 AM, said:

With lifts this long, what kind of extra precautions or engineering has to be done with regard to tensioning?  Is it a bugger trying to connect the two ends of the rope?  Does the tension station have to have an extra chunk of travel to accomodate the extreme length?

-Iain
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As long as the engineer sizes the rope correctly, there isn't much diference from a shorter length. The tension station does have to accomodate more travel; the Flyer has around 14 feet of room for the carriage, allowing it to take up 28 feet of rope (out of 19,800' total). May not sound like much but big ropes on detachables don't actually stretch that much. They have solid cores which keep the diameter stable. Older ropes with hemp cores are more susceptible to stretch over time, owing to the strands squishing the core as they are pulled tight. Slide Brook may have tensioning in both ends, does anyone know?

[Duck]

I'm curious how tensioning at both ends would work!

What the heck? How come my post went all wonky up above?

-Iain

This post has been edited by Duck: 02 June 2005 - 05:21 AM

[SkiBachelor]

When I was at Silver Mountain talking with the lift mechanics, they mentioned if the haul rope snapped, the Gondola Village would be GONE, the Super 8 Hotel GONE, along with any other buildings in a certain radius.

[Jonni]

That's pretty easy to imagine, considering there is at least 55 Tons of tension on it.

[djspookman]

Duck, on Jun 2 2005, 09:20 AM, said:

I'm curious how tensioning at both ends would work!

-Iain
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I'll hike up to either end sometime soon ( I hope) and take some pictures. I live about a minute down the road :)

dave

[KZ]

Just curious, why isn't that lift a gondola? It must be pretty cold and imagine if they had to evacuate the lift. Thats 2 miles of carriers that could potentially be fully loading both ways. Thats a lot of people and how do you shuttle them all out of the liftline? I realize it would be the same situation if it were a gondola but that must be one long cold wet ride in a nasty storm.

[Duck]

Quote

I'll hike up to either end sometime soon ( I hope) and take some pictures. I live about a minute down the road :)

I guess I meant like, from a mechanical standpoint. :) If each tension system is putting on constant force throughout the travel of the bullwheel in its tracks, what keeps the system balanced? Why wouldn't it just bottom out on one end?

Quote

Just curious, why isn't that lift a gondola?

Could be cost? If they wanted to keep the system costs down as low as possible, maybe.

-Iain

[djspookman]

KZ, on Jun 3 2005, 01:02 AM, said:

Just curious, why isn't that lift a gondola? It must be pretty cold and imagine if they had to evacuate the lift. Thats 2 miles of carriers that could potentially be fully loading both ways. Thats a lot of people and how do you shuttle them all out of the liftline? I realize it would be the same situation if it were a gondola but that must be one long cold wet ride in a nasty storm.
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I have wondered this myself. It really should be, as it is shut down on really cold days due to over exposure. The ski patrol has a map hanging up in their patrol room that shows all the work roads that lead up to the Slide Brook Lift line that a few cats could go up to help with the evac. There is also first aid/evac equipment in waterproof bags on every other tower should patrol need it once they get up there. The only problem is that the work roads are long and would require quite some time to navigate up in a cat. They frequently run a cat or two up into the slide brook area though just so that the roads are packed down in case of emergency.

dave

[Jonni]

It's actually not that much. There are only 102 chairs spaced about 200 ft apart from each other. There are evac ropes pre setup on every tower, and each carrier can only hold four people. Evacuation probably would take a while based on the overall length of the lift. The lift itself only runs on holidays and Friday, Saturday and Sunday. If there is any bout of wind they usually don't run it. It is a bit of a cold ride sometimes, but you get over it pretty easily because of how the interesting the ride is.

[liftmech]

Duck, on Jun 3 2005, 04:53 AM, said:

I guess I meant like, from a mechanical standpoint.  :)  If each tension system is putting on constant force throughout the travel of the bullwheel in its tracks, what keeps the system balanced?  Why wouldn't it just bottom out on one end?
-Iain
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Dual tensioning doesn't work on balance. One end is a traditional 'active' system; the other is a passive system. When the lift is built, the passive terminal or carriage is placed almost as far forward as it will go. The rope is then spliced as usual and the active end does all the work. When the active end is about to run out of travel, the passive end is moved back until some of the slack is taken up in the line. That way, lifts as long as Slide Brook don't have to be respliced simply because they run out of carriage travel.

[Duck]

Gotcha, makes sense. Thanks for the clarification!

-Iain

[ceo]

Slide Brook is also the only lift I've been on that has the "this lift might run backward on purpose" signs on the towers, I assume as a way of doing an evac. What good a controlled rollback would do them on a net-horizontal lift, I'm not sure.

[vons]

most HS lifts built by doppelmayr have that sign and capability. The lift is run in reverse to place chairs on line from the park rail and to offload and remove a chair that fails grip force check as it leaves the terminal, very rare.

[jessevanneo]

ZackyJeff, on May 30 2005, 02:51 PM, said:

What about The "Le Express De Sud" at Mont-Sainte-Anne, QUE?? How long is that? Or what about The High Lonesome Express or Olympia Express Quads at Winter Park, CO?? How long are they?
Well, I can take a guess on the shortest one: The "First Time" Express at Park City, UT.
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Sorry but no. The shortest is the Legacy express at COP, Calgary, Alberta