29 replies to this topic

[snoloco]

Poma has had the first hold down sheave assembly integrated into the bottom terminal on many of their lifts rather than having a "tower 1". They did this on the K1 gondola at Killington as shown here.



They also did this on the Skye Peak Express. However, one of their lifts that was installed the same year as the Skye Peak Express has the traditional "tower 1". It is the Burnt Ridge Express Quad at Gore Mountain. I don't know the statistics for other lifts built the same year, but three years later, the Kaatskill Flyer at Hunter Mountain got the "tower 1" at the bottom.

It seems as if Poma used the integrated assemblys for a while and then started to phase them out. Does anyone know of a lift built after 2008 (which is when the Skye Peak Express and the Burnt Ridge Express Quad were built) that uses the integrated compression sheave assemblys that the K1 gondola and so many of their other lifts use. Does Poma still offer them anymore?

Doppelmayr seems to not have used them as much as Poma did. The one lift that I know of that has the integrated assembly is the Grandview Express at Sierra at Tahoe and I have never ridden it, just seen it in pictures and videos. This is what it looks like. Has anyone ever seen this on another lift.

[Backbowlsbilly]

The integrated sheave assemblies were used by Poma then Leitner Poma on lifts with top tensioning. Lifts with bottom tensioning, like the Panoramic Express at Winter Park and Imperial Express at Breck, don't have integrated sheave assemblies because they basically float on the tension of the lift, so they don't work on bottom tension lifts. 2010 was the first year that Leitner Poma introduced the LPA terminal (High Noon Express at Vail) and so far, I don't think that any of the LPA terminals have integrated sheave assemblies. However, Leitner Poma also built some Omega terminals in 2010 before the LPA terminal was completely phased in, the Black Mountain Express at Arapahoe Basin has integrated sheave assemblies and it was built in 2010 plus two Canadian lifts that were built in 2009. (Gold Chair Express at Nakiska and the Canadian Rockies Express at Marmot Basin) Several lifts had integrated sheave assemblies plus a regular tower at the bottom terminal, like the Independence Superchair in Breck. As for Doppelmayr, I know that there were integrated sheave assemblies on Cornice Express at Kirkwood and several high speed quads at Mammoth but other than that, I don't know of any others.

[DonaldMReif]

I don't think they use integrated hold-down assemblies with the LPA terminal design, either top drive or bottom drive.

As for lifts with TB-41 or Omega grips, I think it is dependent on whether the lift is a top-drive lift or a bottom drive lift. If it's a bottom drive lift, they will have a hold-down assembly tower 1 instead of an integrated sheave assembly, and integrated sheave assemblies are only used on most top-drive lifts. I say this because I've noticed a few Omega grip lifts like the Imperial Express SuperChair and the Panoramic Express, which are both bottom drives:

Bottom-drive lifts like the Imperial Express SuperChair look like this:



Top-drive Poma detachables built from roughly 1993-2011 tend to use the integrated sheave assembly. For instance, the Mercury SuperChair:



Though there are exceptions, like a few of Snowmass's high speed quads built around the same time as the Mercury SuperChair: Elk Camp and Two Creeks are top drives but they have hold-down tower 1s instead of an integrated sheave assembly, and their terminals have the same design as the Mercury SuperChair and Rocky Mountain SuperChair.

[snoloco]

Backbowlsbilly, on 26 May 2014 - 02:19 PM, said:

Lifts with bottom tensioning, like the Panoramic Express at Winter Park.

I believe that the Panoramic Express is a bottom drive top tension because those three mast gondola terminals that they used on it must have tensioning at the return. The two mast chairlift terminals can have the entire structure move and have tensioning at both terminals. The Skye Peak Express is a top drive, top and bottom tension. The K1 Gondola is a top drive bottom tension. I can tell because it uses the same terminals that the Panoramic Express uses and the bullwheel brakes stick out of the terminal at the top.

I guess it was only an option on return terminals because drive terminals need the extra space for the drive components. The drive components also weigh a lot, so the terminal cannot support both an integrated compression sheave assembly and be a drive terminal.

The only place I see an integrated assembly on a bottom drive lift is on the Yan modified by Poma high speed quads at Killington. I am guessing that they were able to do this because of Yan's terminal design, but Poma's doesn't allow this. The other two Poma high speed quads at Killington are the Needle's Eye Express and the Ramshead Express. Both are bottom drives and have "tower 1's". Mount Snow has a lift that is the same design as the Mercury and Rocky Mountain Superchair which is the Nitro Express. It is a top drive and has the integrated assembly. However, the Sunapee Express at Mount Sunapee is the same design, but a bottom drive with a "tower 1". Mount Snow's Canyon Express is exactly the same as Killington's Ramshead Express except it is a top drive. It has the integrated assembly as well.

I guess that Poma made this an option on the Challenger and Omega return terminals and most ski areas got it when it was an option with the exception of a few. They decided not to offer it on LPA terminals.

[Peter]

Doppelmayr seems to only use them on lifts with height-adjustable terminals, hence the Mammoth and Kirkwood examples.

[Peter]

Backbowlsbilly, on 26 May 2014 - 02:19 PM, said:

The integrated sheave assemblies were used by Poma then Leitner Poma on lifts with top tensioning. Lifts with bottom tensioning, like the Panoramic Express at Winter Park and Imperial Express at Breck, don't have integrated sheave assemblies because they basically float on the tension of the lift, so they don't work on bottom tension lifts.

I don't think that's right. The Bridger Gondola is bottom tension with an integrated assembly.

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•  IMG_9600.JPG (1.6MB)
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[snoloco]

Peter, on 26 May 2014 - 05:08 PM, said:

I don't think that's right. The Bridger Gondola is bottom tension with an integrated assembly.

I think he mixed up bottom tension and bottom drive. Drive terminals cannot have the integrated assembly, but return/tension terminals can.

[Backbowlsbilly]

snoloco, on 26 May 2014 - 05:24 PM, said:

I think he mixed up bottom tension and bottom drive. Drive terminals cannot have the integrated assembly, but return/tension terminals can.

Yep, sorry about that, my bad on that one. I think Doppelmayr has a couple of integrated sheave assemblies in the top terminals of lifts as well, like this one at Mammoth.

[liftmech]

Few detachable lifts are bottom drive. I suspect that's why none of you can come up with an example of a floating compression on a drive terminal. I don't see any reason why one couldn't have a setup like that; there isn't a great deal of additional weight involved since the upward force of the rope offsets much of the weight of the assembly. Both of our Omega lifts (1998) have these assemblies; one of them is the true Omega terminal where the whole thing moves and the other is a fixed terminal/internal carriage.

For what it's worth, Yan lifts had floating compression assemblies on many of their 80s-vintage DTTs.

[DonaldMReif]

The only detachables I can think of that are bottom drives anyways all happen to go above timberline - Panoramic Express, Imperial Express SuperChair, Outback Express, Kensho SuperChair.

You know, I think the Grand Summit Express at Mt. Snow has an integrated top terminal sheave assembly.

And there are quite a good number of quads and six packs that use both the integrated sheave and hold-down tower right next to each other: the Independence SuperChair, Quicksilver Super6, the uphill end of the Peak 8 SuperConnect midway load, the Ruby Express, and the Snowmass Village Express, to name a few.

[SkiDaBird]

A lot of old Yan or CTEC fixed grips with bottom drive and bottom tension have the attached sheave. Alta and Solitude have multiple each.

[SkiDaBird]

DonaldMReif, on 26 May 2014 - 08:08 PM, said:

The only detachables I can think of that are bottom drives anyways all happen to go above timberline - Panoramic Express, Imperial Express SuperChair, Outback Express, Kensho SuperChair.

You know, I think the Grand Summit Express at Mt. Snow has an integrated top terminal sheave assembly.

And there are quite a good number of quads and six packs that use both the integrated sheave and hold-down tower right next to each other: the Independence SuperChair, Quicksilver Super6, the uphill end of the Peak 8 SuperConnect midway load, the Ruby Express, and the Snowmass Village Express, to name a few.

The treeline is a factor, but not the exclusive reason why (Sunnyside Alta, Eagle Solitude). This was discussed in another thread.

[DonaldMReif]

That most of the above-timberline lifts at the resorts I've visited are bottom drive has less to do with them going above timberline, and more with the resort's lift planners not wanting to run underground utility lines up to the top of the mountain, and make the drive more accessible for maintenance crews.

Ah well. These integrated assemblies can differ from lift to lift. They are 12 sheaves per side on the Rocky Mountain SuperChair, Highline Express, Teacup Express and a few others, but they noticeably generally are eight sheaves per side on the Mercury SuperChair and the four Winter Park quads with integrated sheaves.

[JSteigs]

Backbowlsbilly, on 26 May 2014 - 02:19 PM, said:

Lifts with bottom tensioning, like the Panoramic Express at Winter Park and Imperial Express at Breck, don't have integrated sheave assemblies because they basically float on the tension of the lift, so they don't work on bottom tension lifts.

I believe that tower one of Polar express at Bear Valley in CA, is integrated (90% sure). The bottom is a return that is also floating, It has rams but never really moves on it's own.

[Allan]

We've got a Yan RTT, a Doppelmayr FGQ, and a T-Bar all with assemblies attached to the terminal.

[liftmech]

Backbowlsbilly, on 26 May 2014 - 02:19 PM, said:

Lifts with bottom tensioning, like the Panoramic Express at Winter Park and Imperial Express at Breck, don't have integrated sheave assemblies because they basically float on the tension of the lift, so they don't work on bottom tension lifts.

As long as the rope is under tension, it doesn't matter which end that tension is applied from....

[floridaskier]

Is there more force on the rope right next to the drive terminal? Most lifts seem to have more sheaves for the same angle change right out of the drive terminal. Case in point: Silver Lake Express at Deer Valley, which has depression towers at both ends. 16 sheaves at the drive end and 8 at the return end, when the angle change is steeper at the return

[snoloco]

The arrival side must be under greater tension. Some older fixed grips with bottom drive that I have ridden have more depression sheaves on the downgoing side at the drive terminal. The Vernon Triple at Mountain Creek has 12 on the downline at the bottom terminal and only 8 on the upline. The now defunct Triple Chair at Hidden Valley, NJ has 8 on the downline and 6 on the upline at the bottom drive terminal. Both are Borvig triples. The Flyer Express at Jay Peak has a tower 1 with 12 on each side, but some of the in line hold downs have 10 on the downline and 8 on the upline. This lift is a bottom, drive bottom tension to my knowledge. I do not build lifts or work on them, but I think that the extra tension on the down line in a bottom drive installation may be enough to warrant extra sheaves on hold downs. I have not noticed this on any top drive lifts I have ridden.

[SkiLiftsRock]

The only detachable lifts I have pictures with integrated compression sheave assemblies are the 3 HSQ's at Sierra at Tahoe.

Here is Grandview Express: http://youtu.be/QlSUFXCKnfc

And a few pictures:

 Grandview Express 1.JPG (535.36K)
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 Westbowl Express.JPG (612.69K)
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 Easy Rider Express.JPG (731.95K)
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[Nate214]

This is the return terminal on our 1989 Poma FGQ. The background story I got from Walter Ruegg about this terminal is it was a first or maybe an only of it's kind. The story was over a lunch meeting discussing the new lift to be installed. During this meeting they were discussing what they can do different the design was going to be two post tower with a crossarm connecting the two after the return bullwheel. They drew this up on a napkin and liked the designed. They were not sure this would be possible after the engineering was done they made it possible. I know that the single upright tower holding this up is solid filled with concrete and has a massive foundation. I don't know if any bottom returns out there have also been designed the same way.  base3.jpg (114.62K)
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Number of downloads: 108  base1.jpg (158.72K)
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