16 replies to this topic

[JohnRW]

I work at Arctic Valley Ski Area in Anchorage, AK. Each fall we have issues with our Riblet double chairs blowing over the comm lines. Sometimes they just rest on the comm line, sometimes the comm line gets caught underneath the cotter pin on the chair, and once a chair blew over, missed the comm line, swung back down and went through a sheave train backwards (a very bad day).

We're planning to tighten the comm lines in the two places where this usually happens, but with the winds so strong up there (100+ mph at least once a winter) I'm afraid there isn't a permanent solution. Any suggestions?

Thanks!

John

[Emax]

JohnRW, on 18 July 2011 - 01:37 PM, said:

I work at Arctic Valley Ski Area in Anchorage, AK. Each fall we have issues with our Riblet double chairs blowing over the comm lines. Sometimes they just rest on the comm line, sometimes the comm line gets caught underneath the cotter pin on the chair, and once a chair blew over, missed the comm line, swung back down and went through a sheave train backwards (a very bad day).

We're planning to tighten the comm lines in the two places where this usually happens, but with the winds so strong up there (100+ mph at least once a winter) I'm afraid there isn't a permanent solution. Any suggestions?

Thanks!

John

In the two locations subject to this problem, the most sure-fire solution is to run the wiring underground.

[Allan]

What Emax said... we had to do that in our long high span on our alpine lift. We put ours in 2" ducting.

[Emax]

Allan, on 18 July 2011 - 04:31 PM, said:

What Emax said... we had to do that in our long high span on our alpine lift. We put ours in 2" ducting.

Please elaborate.

[Allan]

We buried 2" (maybe it was 3") communications ducting for the 430 foot span at the top of our YAN and ran the comm line in there; it's very windy in that long span.

[Emax]

Allan, on 18 July 2011 - 08:02 PM, said:

We buried 2" (maybe it was 3") communications ducting for the 430 foot span at the top of our YAN and ran the comm line in there; it's very windy in that long span.

How did you break out the conductors for running up the towers? Did you run them inside the tower tube or in a surface conduit?
I'm interested because we need to do this on two of Brian Head's lifts. One of my considerations would be to provide draining for the conduit to prevent "ice-choking" the cable.

[Allan]

Emax, on 18 July 2011 - 08:46 PM, said:

How did you break out the conductors for running up the towers? Did you run them inside the tower tube or in a surface conduit?
I'm interested because we need to do this on two of Brian Head's lifts. One of my considerations would be to provide draining for the conduit to prevent "ice-choking" the cable.

Our conduit runs from the drive to the second to last tower (it runs up the side of the ladder.) The last tower to the drive (75 feet) has it's own less wind affected aerial run so we didn't have to break conductors out of the conduit at all!

[Emax]

I would like to hear comments from others who have used the below-ground solution to tower wiring. Clearly, though more costly, this method is immune to most of the problems that overhead com-lines can present. No doubt, it also has its own family of pitfalls. From those who are experienced in this arena, I'd like to know what techniques have proven to be a good balance between workability and effectiveness.

One bonus that comes to mind is the ability to perform at least some troubleshooting from ground level. From a technician's point of view, lower is always better. No doubt the insurance company would agree.

[Razvan]

 cable trench cross-section.gif (184.66K)
Number of downloads: 93Doppelmayr specs for a buried cabling attached. 8-MGD gondola.
The inventor of ground level troubleshooting is worthy of a Nobel prize.

This post has been edited by Razvan: 19 July 2011 - 11:32 AM

[JohnRW]

Emax, on 18 July 2011 - 03:30 PM, said:

In the two locations subject to this problem, the most sure-fire solution is to run the wiring underground.

Thanks!

I'll put that on the to-do list right after we replace our open-gear t-bar drive. Maybe a few years ...

[Emax]

JohnRW, on 19 July 2011 - 07:10 PM, said:

Thanks!

I'll put that on the to-do list right after we replace our open-gear t-bar drive. Maybe a few years ...

Jeeze - just trying to help...

[cjb]

Another option is to weld or similarly attach an extension to raise the height of the comline further. I have done this on a couple of towers where the comline crossed the lift line. It worked well, just make sure that it is strong enough to handle the wind you see. I think we used 2x2 square tubing. 1/4" thick and gusseted at the bottom. Relocate your strand-vises and good luck

[cjb]

Bud, we put the top 4? towers of lift 11 at Snow Valley in the ground after rime and wind wrecked the comline for the third time. I don't remember the specifics of what we used but in general we ran the existing comline down the tower and into a junction box on the side of the tower. Not too low or it will be lost when it snows! It ran to each tower and through a junction box which allowed for the tower circuit functions. We ran those in smaller conduit (1"?) and into the tower at the top. We did this about 6-7 years ago and as of my departure last year I don't think we ever had a problem with it. I do remember that part of the conduit was buried and some was left above ground due to the rock and difficult digging. Dan could probably look into any details you may want to know about what we did.

[Emax]

cjb, on 20 July 2011 - 07:26 PM, said:

Bud, we put the top 4? towers of lift 11 at Snow Valley in the ground after rime and wind wrecked the comline for the third time. I don't remember the specifics of what we used but in general we ran the existing comline down the tower and into a junction box on the side of the tower. Not too low or it will be lost when it snows! It ran to each tower and through a junction box which allowed for the tower circuit functions. We ran those in smaller conduit (1"?) and into the tower at the top. We did this about 6-7 years ago and as of my departure last year I don't think we ever had a problem with it. I do remember that part of the conduit was buried and some was left above ground due to the rock and difficult digging. Dan could probably look into any details you may want to know about what we did.

Thanx Chuck.

[JohnRW]

Emax, on 19 July 2011 - 11:19 PM, said:

Jeeze - just trying to help...

Sorry! I wasn't trying to be sarcastic. The advice is definitely appreciated.

We operate almost entirely with volunteers, so larger projects are fairly difficult to pull off. Though the more I think about it, running the line on the ground in conduit (it's pretty damn rocky up there) may not be too tough.

Thanks again!

John

[JohnRW]

cjb, on 20 July 2011 - 07:15 PM, said:

Another option is to weld or similarly attach an extension to raise the height of the comline further. I have done this on a couple of towers where the comline crossed the lift line. It worked well, just make sure that it is strong enough to handle the wind you see. I think we used 2x2 square tubing. 1/4" thick and gusseted at the bottom. Relocate your strand-vises and good luck

Thanks! We'll look into that option as well.

[hvteleman]

we marked our derail switch drops on return side ...easy to identify which side needs attention before climbing tower..most of the lifts have the comm line pigtailed into a phone box below each tower with the switch drops run in conduit from box to inside tower...wish we would have run inside conduit up inside crossarms....most times its chewed from critters