Last winter, a chairlift in West Virginia, identical in design to that at our small local ski area, suffered a catastrophic failure (the weldment of the "T" at the top of a tower failed, sending it to the ground ( http://abcnews.go.com/US/25-people-fall-derailed-ski-lift-west-virginia/story?id=37080245 ). As a result, ours was shut down for a week of weld inspections. It finished out the season, but it looks like we're getting a new one!
The company doing the work was a solo operator, running a Spectra Focus instrument. He'd done the topo and set control previously and this morning was setting out both the centerline and offset hubs for the lift line.
Know nothing about robotic total stations, but watching him set the nails on the hub, but it looked like the setup he had was producing great precision. Instrument was 5" though, which surprised me a bit.
I asked him if he had to do the anchor bolts for the towers. He said that was up to the contractor; he was setting out just a single point for each tower.
One thing I've learned (here!) was to limit the questions to about 30 seconds, leaving him to "stay on his game". Wouldn't want to be responsible for the rope coming off a sheave due to excessive jawboning.
I've never seen hubs like that, nor ones set sticking out of the ground so far, apparently doubling as their own lath. Huh.
Those look like bank plugs...usually 2x4s cut on the diagonal.
I always wanted to build a chairlift. I was a lift operator at Mammoth Mountain in 1982 and 1983. I also operated the T-bar. Which reminds me, why do you need a lift on that little hill LOL? You could walk up there in 5 minutes.
Dave Karoly, post: 382089, member: 94 wrote: Those look like bank plugs...usually 2x4s cut on the diagonal.
I always wanted to build a chairlift. I was a lift operator at Mammoth Mountain in 1982 and 1983. I also operated the T-bar. Which reminds me, why do you need a lift on that little hill LOL? You could walk up there in 5 minutes.
Hey! The old lift took SIX minutes! It's got 650' of vertical. it takes me 27 minutes to do it hiking with skis on the back, 15 minutes with skins. (I know first hand).
Silly people. Snow and ice should be observed out your window only...............unless someone is paying you really well to be out in it.
rfc, post: 382098, member: 8882 wrote: Hey! The old lift took SIX minutes! It's got 650' of vertical. it takes me 27 minutes to do it hiking with skis on the back, 15 minutes with skins. (I know first hand).
I forget now, the lifts were specified in persons per minute, I think. Slower lifts (such as the bunny hill) had the chairs closer together.
The new high speed lifts have a lot more capacity.
I always laugh when I get in a two minute lift line and the kids ahead of me are whining about it.
I remember 45 minute waits on the weekends in the 1970s.
Years ago Timberline called our office on a Friday asking for a pole line profile for one of the lift lines at the top of the mountain that weekend. The day started out clear and beautiful and we finished up the survey just as the first winter storm was hitting. They ended up giving us all season passes. Well worth the Saturday work.
Dave Karoly, post: 382101, member: 94 wrote: I forget now, the lifts were specified in persons per minute, I think. Slower lifts (such as the bunny hill) had the chairs closer together.
The new high speed lifts have a lot more capacity.
I always laugh when I get in a two minute lift line and the kids ahead of me are whining about it.
I remember 45 minute waits on the weekends in the 1970s.
My son takes me skiing and we end up in the back where there aren't many people but great snow, high-speed quad lift, takes maybe 10 minutes to ski down,,,,,if you take your time.
No lines, get to the chair, get on and seems like a minute later you are skiing. Do that about 5-10 times and he wants to go again!!!!,,,,,,I say,,,,I'm going to the lodge for a while.
My legs were jelly by then.
Kinda like the slow lifts.
What's wrong with a 5" instrument?
Don't snow enough or stay on the ground long enough for skiing in NE Texas.
😎
Seems last few years you guys back East get snow while we up in Alaska get bubkis. With El Ni̱o waning maybe that's about to change (I hope). Last couple years skiing' been less than spectacular. Nothing wrong with a 5" gun for 95% of work we do.
What are the tolerances for the job?
1000 * tan(5 seconds) = 0.024
and that can be improved by averaging.
Williwaw - " Nothing wrong with a 5" gun for 95% of work we do."
You are very right about that ! I had a friend that was (is) driven by precision so he bought a 1" Kern for woods work, one of the early electronic instruments, very large , heavy, expensive and prone to battery cable problems. It was an awesome instrument, what Kern wasn't, but a beast to carry through the woods. The bottom line was that he didn't get any better results with it than he would have with a lighter, cheaper 5" instrument. When you struggle to get 100' traverse lines at times, 5" vs 1" doesn't make much difference, however a good traverse set will. I still remember when having a 20" Transit was big time precision because most surveyors were running 1' instruments at the time.
Don't get star struck by fancy equipment ( I do love it too though) , technique, procedure and knowledge of the profession are far more important.
T.W.
John Putnam, post: 382108, member: 1188 wrote: Years ago Timberline called our office on a Friday asking for a pole line profile for one of the lift lines at the top of the mountain that weekend. The day started out clear and beautiful and we finished up the survey just as the first winter storm was hitting. They ended up giving us all season passes. Well worth the Saturday work.
How did you do it? Offsets?
Solo?
Who's on the other day end of the radio on his vest?
Probably the wife...
Scott Zelenak, post: 382360, member: 327 wrote: Solo?
Who's on the other day end of the radio on his vest?Probably the wife...
Very astute! Actually, there was a girl there from a local engineering firm that specializes in chair lifts. I think they were going to be doing/had been doing the site engineering. She was "baby sitting" the robot, occasionally looking through the scope. I asked her a few questions about it (the gun), and she really wasn't familiar with it. Wasn't sure what purpose it served to have her at the gun. He had the DC, and the field book. Didn't want to make a pest of myself asking stupid questions.
Progress is moving along. Here is one of the base station plinths formed up ready for pouring: 
Now, they've got the base station concrete completely done; steel is going on. They delivered the wire rope (spool in front of the c/l target)
I was curious about the tolerances required for the anchor bolts. Given that they were pre-welded at set distances apart each steel column would be sure to set on the plinth without too much trouble, but when it comes time to bolt the cross bracing between them, I would think you'd need to be pretty close.
I inspected the holes in the base flanges though--they were about 3" (side to side) by 5" long (in the direction of the lift travel). That would give a total play side to side between the two of almost 2", a lot greater than I thought they'd have planned.
What mountain is this?
Waterville Valley is relocating a fixed triple to Green Peak Expansion. Can't wait. Won't be long. Come to think of it, the earliest I've skied is this date, October 4th, back in the mid 90's at Killington.
Suicide Six...It's owned by the Woodstock Resort Corporation (who own the Woodstock Inn). It's here:
It's not a big area, but when you can be on the chair five minutes from your front door, it sure beats the slog up to Killington.
Top terminal under way. Most of the tower bases are in except one, where they had to blast ledge. I found the drawings though. The stations for each tower are called out in what looks like slope distance from the monster target beyond the bottom terminal. The surveyor put two of those odd looking "2 x 4 cut diagonally" hubs astride each tower base at 20' O/S, and one beyond (up hill) each one. There are dimpled nails on the centerlines of the forms; I think the builder sets up on the uphill centered hub, and backsights down to the monster target then to the nails for precise positioning.
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Off topic question: In SurvCE, if you use the "Stake Points" to stake a line, and you're set up ON one of the points that is the endpoint of the line, can you use this routine to set a bunch of points on the line, without moving the scope (except vertically)? Never tried it.
