chairlift geekery - Baldy Express at Snowbird

SkiingInABlueDream · Mar 16, 2015

All the recent Snowbird chatter reminds me of something really interesting (to me at least) about the Baldy chair.

Has anyone else who's ridden it noticed that it's line kinks slightly rightward near the top? With pretty much every ski lift I've ever ridden, the towers are all exactly aligned. (I'm excluding atypical lifts like the old South Ridge chair at Kton which turned via bullwheels, or lifts that detach at a midstation like the Kton gondola or Alta Collins.)

But the Baldy chair, the lift's line distinctly turns to the right at one point. It's subtle but noticeable in this picture:
http://www.skilifts.org/old/images/resort_images/ut-snowbird/baldy/liftline.jpg

From what I could tell, it works because the sheave wheels on (IIRC) 2 towers are slightly tilted from vertical. This slight tilt enables the wheels to support horizontal load created from the lift's path turning.

I had never seen anything like that before. Has anyone else noticed this? Sorry but I thought it was really cool!

SkiingInABlueDream · Mar 16, 2015

Crap, didn't mean to post this to the TR's forum. Can it be moved please?

ScottySkis · Mar 16, 2015

skifastr said:
Crap, didn't mean to post this to the TR's forum. Can it be moved please?

You have to forward this to administration and they can move it

thetrailboss · Mar 16, 2015

skifastr said:
All the recent Snowbird chatter reminds me of something really interesting (to me at least) about the Baldy chair.

Has anyone else who's ridden it noticed that it's line kinks slightly rightward near the top? With pretty much every ski lift I've ever ridden, the towers are all exactly aligned. (I'm excluding atypical lifts like the old South Ridge chair at Kton which turned via bullwheels, or lifts that detach at a midstation like the Kton gondola or Alta Collins.)

But the Baldy chair, the lift's line distinctly turns to the right at one point. It's subtle but noticeable in this picture:
http://www.skilifts.org/old/images/resort_images/ut-snowbird/baldy/liftline.jpg

From what I could tell, it works because the sheave wheels on (IIRC) 2 towers are slightly tilted from vertical. This slight tilt enables the wheels to support horizontal load created from the lift's path turning.

I had never seen anything like that before. Has anyone else noticed this? Sorry but I thought it was really cool!

It sure does have a slight angle to it. You can really see it from the Bookends side. The top terminal sits just slightly to looker's right of the shoulder of Baldy. They did this angle, as you said, by angling the sheave trains on some of the towers. It is interesting.

BushMogulMaster · Mar 16, 2015

Yes, they deflect the haul rope with a series angled deflection sheaves, or, in more extreme cases, an actual deflection bullwheel on the return side. Want to see something cool? Study this modern fixed-grip double at Breck for a few minutes:

SkiingInABlueDream · Mar 16, 2015

BMM: "deflection sheaves/bullwheel" > Good to know the terminology.
I've seen that picture before but I've never been able to figure out what the heck is going on there; I just see a string of not-fully-untangled Christmas tree lights. Is there something like a 90-degree deflection via sheaves in there?

I've only been to Breck once and it was before I knew about that lift. Wish I could have ridden it!

SkiingInABlueDream · Mar 16, 2015

thetrailboss said:
It sure does have a slight angle to it. You can really see it from the Bookends side. The top terminal sits just slightly to looker's right of the shoulder of Baldy. They did this angle, as you said, by angling the sheave trains on some of the towers. It is interesting.

Did not think to study the lift on any of my laps in Bookends. Kind of wish I had now but I was always too engaged with the run.

I also wonder why they did it this way. I'm sure they didn't accidentally construct the top & bottom terminals mis-aligned!:lol:

SkiingInABlueDream · Mar 16, 2015

Ok, as if I haven't analyzed this enough already:
As the rope passes over and around sheaves and bullwheels, I assume it's important for the rope to lie in the plane of the wheels. (In other words, bullwheels are usually oriented horizontally, so haul ropes approach and depart the bullwheel along nearly-horizontal trajectories. Same thing with normal sheave trains, except in a vertical plane.)
So with deflection sheaves like on the Baldy lift, how do you account for varying amounts of rope sag? It would seem like the rope might not always be aligned with the first sheave wheel, depending on much the rope sags from chair loading? Or maybe it doesn't vary enough to matter?
Yes... I'm a geek.

mbedle · Mar 16, 2015

BushMogulMaster said:
Yes, they deflect the haul rope with a series angled deflection sheaves, or, in more extreme cases, an actual deflection bullwheel on the return side. Want to see something cool? Study this modern fixed-grip double at Breck for a few minutes:

I can't figure out this picture. I see three chairs coming in and only two exiting.

mbedle · Mar 16, 2015

Just looked it up, wow - was there last year and wish I took that for a ride. unbelievable!

skiNEwhere · Mar 16, 2015

Chair 5 at Breckenridge has a 3 degree left turn as well, I didn't even notice it until someone told me it's so subtle. They also have a collapsible tower they use in the summer for the alpine slide. It is literally on hinges laying on the ground.

Breck has all sorts of quirky lifts, they also have the only double loading lift in the US (quicksilver) and a t bar that makes a left turn similar to the old south ridge triple at killington.

Don't worry, you're not the only chairlift enthusiast on this site.

skiNEwhere · Mar 16, 2015

ImageUploadedByAlpineZone1426541000.789648.jpg

Here's a pic I took of the baldy express sheaves back in April. May go out there again in a couple weeks too, I'll try to take a couple more pics if your interested.

Madroch · Mar 16, 2015

Can't figure the breck chair out...

thetrailboss · Mar 16, 2015

Here is a shot from SkiLifts.org

skiNEwhere · Mar 16, 2015

thetrailboss said:
Here is a shot from SkiLifts.org

Pretty sure that's the same as the pic the op posted

SkiingInABlueDream · Mar 16, 2015

skiNEwhere said:
Here's a pic I took of the baldy express sheaves back in April. May go out there again in a couple weeks too, I'll try to take a couple more pics if your interested.

Cool, thanks for sharing that. That's pretty much the pic I would have taken if I'd thought of it.

SkiingInABlueDream · Mar 16, 2015

skiNEwhere said:
Pretty sure that's the same as the pic the op posted

Domeskier · Mar 16, 2015

Madroch said:
Can't figure the breck chair out...

Here's a video of the chair in action that sort of gives you an idea of what's going on:

xlr8r · Mar 16, 2015

Silver Strike at Deer Valley also has a turn, I rode it a few years ago. It takes 3 towers to make the turn, tension slightly angled to start the turn, then drops down into a very angled depression in the middle, and then rises to another slightly angled tension to finish the turn.

Six Shooter at Moonlight Basin/Big Sky and the Cabriolet at Canyons also have turns. All built around the mid 00s by Doppelmayr/CTEC around when they merged. I think they are built this way due to property lines or angling around real estate development. Anybody know of any others.

thetrailboss · Mar 16, 2015

skiNEwhere said:
Pretty sure that's the same as the pic the op posted

Just saw that....doh! :dunce:

chairlift geekery - Baldy Express at Snowbird

Active member

Active member

Well-known member

Moderator

Industry Rep

Attachments

Active member

Active member

Active member

Well-known member

Well-known member

Active member

Active member

New member

Moderator

Active member

Active member

Active member

Well-known member

Active member

Moderator

Similar threads