
How ski lifts are installed: Vail's new Chair 5 (2011) [video] - curtis
https://www.youtube.com/watch?v=8CSxkYnyFg0
======
blhack
Those bolts strapped to the grating as they were putting the top piece on... I
love that stuff!

What I mean is: pre-optimizations like that. My current cofounder and I build
and run fire effects [flamethrowers] at music festivals, and every load-
in/setup is a fun game of seeing what ways we can optimize our setup process.
Stuff like figuring out the wrenches and tools we need to assemble a specific
component, and then storing those tools _with_ the component.

Seeing those bolts sitting on the grate like that (I think it was 4 on each
side) means that somebody had the foresight to realize that it was easier to
strap the bolts to the piece like that, than to have the guys assembling it
carry them with them up the ladders (imagine if they forgot one, what a pain
that would be).

So freaking cool.

~~~
tinbad
"means that somebody had the foresight to realize that it was easier to strap
the bolts to the piece like that"

Not to curb your enthusiasm or downplay the ingenuity of those builders, but
the assembly process seems fairly repetitive and easier to optimize over time.
I doubt they had this foresight before doing the first (ever) pole.

~~~
krschultz
Easier to optimize than what? I used to work on manufacturing nuclear
submarines. We built exactly 1 of many things. You'd think that would mean
there was no repetition, but that's not the case. The processes are
repetitive, even if the product is not. Everything can and should be
optimized, that's the only pathway to higher productivity.

~~~
tinbad
Easier than doing it the first couple times: whoever came up with the
improvement first, before this knowledge was institutionalized within the
organization/field.

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jonah
Be sure to check out the helicopter they're using, a Kaman M-MAX. It had dual
counter-rotating rotors and not tailrotor. It's also basically designed
specifically for this kind of lifting/hauling job with a very narrow cockpit
allowing the pilot to easily see what he's doing below.

[http://www.kaman.com/aerosystems/solutions/air-vehicles-
mro/...](http://www.kaman.com/aerosystems/solutions/air-vehicles-mro/k-max)

[https://www.youtube.com/watch?v=iEx3dJTIjww](https://www.youtube.com/watch?v=iEx3dJTIjww)

They've also developed an unmanned version for military resupply missions:

[https://www.youtube.com/watch?v=jQ4X7Y2ydS0](https://www.youtube.com/watch?v=jQ4X7Y2ydS0)

[http://jalopnik.com/this-is-the-weirdest-dang-helicopter-
i-h...](http://jalopnik.com/this-is-the-weirdest-dang-helicopter-i-have-ever-
seen-1794078945)

~~~
Gravityloss
The synchropter is originally a German design. It's a fascinating way of
solving the torque problem.

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robryk
Usually tying an in-flight helicopter to the ground is a huge no-no. E.g.
there's a subtle sequence of steps for airlifting a casualty from a steep
hillside that prevents the helicopter from ever being connected by a rope to
the ground (the reasoning, AFAIK, is that the helocpter migth need to depart
or move at a very short notice and the line may hinder it and injure people if
it breaks).

It seems that there are reasonably long period of time here when the
helicopter is still connected to a tower segment when the workers are in the
process of screwing bolts in. Why isn't this problematic?

~~~
nippoo
In an emergency the helicopter can just drop the load: the pilot can release
the hook and fly away. Unlike carrying a casualty, this is unlikely to be
anywhere near as dangerous. If the tower is somewhat bolted on, it'll probably
stick there long enough for the other bolts to go in. Worst case, it tips over
and falls to the ground, but in any case it's unlikely for there to be any
injuries.

~~~
robryk
As far as I know, one of the reasons why dropping the load is considered
dangerous is that the line that was holding the load will be suddenly released
from high tension, so it will go flying at fast enough speed to injure
someone.

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rhcom2
And how ski lifts are destroyed:
[https://www.youtube.com/watch?v=u4WPSZojtyE](https://www.youtube.com/watch?v=u4WPSZojtyE)

~~~
raldi
This could easily be its own front-page submission.

~~~
grecy
I ran ski chairlifts for a few years when I was sick of sitting at a desk.

We were shown this video during our training, and our boss said with a very
straight face that if she were ever on a chair that started rolling backwards,
she would jump off.

The reason "rollback" can happen is because the weight of all the people is
only on one side of the line, and that weight wants to come back downhill. The
chair has a couple of different kinds of brakes that are supposed to prevent
this, but you can see what happens when it fails / is engaged too late.

Two broken legs are better than that.

NOTE HOWEVER: Newer "Detachable" or "high-speed" chairs and gondolas are often
designed to run in reverse, so don't immediately jump off one of those if it
goes backwards.

~~~
arethuza
As someone who has spent a lot of time sitting in chairlifts over the years
that's a pretty terrifying video - amazing that I'd never even considered what
would happen if a lift ran backwards!

I wonder if the "up and down" lifts that go down and up a valley (e.g. there
is one at Alpe d'Huez) or over a ridge (e.g. the one at Val d'Isere) suffer
from the same problem - even allowing for the fact that I'm pretty sure that
they are modern detachables.

~~~
grecy
> _amazing that I 'd never even considered what would happen if a lift ran
> backwards!_

Until you work a chairlift they are all fun and games.. after.. well, they are
serious pieces of heavy machinery.

On my first day running one I hit the stop button and then watched the chair
continue for ~5 feet, which snapped a young ladies Femur clean in two about 3
feet from my face. Safe to say that was not pretty.

I've also seen countless people knocked out by them, seen full derailments
(scary) but happily never seen fingers or hands go into places they shouldn't.

Also had guests fall off the chair and die.

so yeah, very serious.

> _I wonder if the "up and down" lifts that go down and up a valley suffer
> from the same problem_

My gut says yes, because when all is said and done they are moving a lot of
mass from down to up, and all that mass is still only on one side.

~~~
hammock
Femur...What... Can you give note detail on that? Emergency stop?

~~~
grecy
I was at the top station, she was coming up on a chair by herself. She had one
arm wound through the slats in the back of the chair, and was using her phone
with the other hand so she didn't see the unload coming up.

Her snowboard was dangling and caught on the beginning of the unload ramp.
About that time I hit the e-stop, though of course a many-hundred ton machine
with a 1200hp drive motor is going to continue for a bit before it actually
stops moving. Even with the e-stop a big heavy four-seater fixed grip will go
6-8-10 feet or so. If it wasn't my first day maybe I would have hit that
button sooner.

(Side note, they make the chairs heavy on purpose so they are less susceptible
to the wind.. Otherwise they blow around and hit towers. I have been sitting
on a chair when it slammed sideways into a tower before. Not fun)

Her board caught in the snow and started to pull her forwards off the chair,
but her arm through the slats stopped that happening, so the chair started to
swing back and load up with all the forces. It got to quite an impressive
angle before something gave way, and it was her femur, because it was half off
the leading edge of the chair.

Obviously that was a major ski patrol incident, and I had to write witness
statements and draw diagrams of the whole thing in case she tried to sue the
resort within 7 years (California...)

Another day I watched a liftie raking the top ramp look up just in time for
the chair to smash him right on the forehead - he was out cold for 10 minutes.

That same guy was later scooped up by the chair at the top, and the sudden
weight in the chair as it went around the bull wheel caused a derailment. The
haul rope (cable) came out of the bull wheel (the big wheel at the top). This
is a pain in the ass to fix, especially when there is the weight of hundreds
of people sitting on the haul rope. That was a full manual evacuation, which
takes hours and hours of lowering people down with ropes.

Some of my best days were "saving" people from getting hit. At the bottom once
you have worked 100+ days you can see an issue coming three chairs before it
happens, so it's like you are Superman. Often kids would be in the worst
possible place and were about to get creamed by the big heavy chair. It's not
possible to hold the chair back (even if you could , maint. doesn't want us
doing that, we can damage stuff) and the e-stop won't stop it in time. I hate
seeing kids get hit, so I would run over and tackle them to the ground,
holding them down while the chair sails over both of us. Everyone lined up
would cheer. It was great fun!

Of course, we screwed around a lot too - holding on the chair and letting it
drag us along the snow, sitting on the chair and waiting to be the last to
jump off into the powder, trying to "hurdle" the chair as it comes towards you
(which was insanely hard because you have to jump the chair, but duck the
steel bar at the top)

All in all, really, really good times.

~~~
hammock
What an awful thing to happen on your first day. Thanks for sharing your
stories. Another reason added to the list why I'll never try snowboarding
(skiier).

I was out in Aspen two weeks ago and we were wondering if the lifties get drug
tested (never thought about it before). I said they have to, they are
responsible for other people's lives and safety. My friends all said no way.

What's your experience?

~~~
grecy
I have not been a liftie since about 2007, and back then I think drug testing
was at bosses discretion.

Where I worked literally every single employee on the mntn smoked, so if you
were a pain the neck to your boss they would ask for a drug test and you were
basically fired.

In Canada, as far as I know, it never happened (I worked there a few seasons,
everyone smoked)

I would say on the majority of days that other people lives and safety were in
our hands, the vast majority of lifties were severely hungover and/or stoned.

------
caconym_
Cool video of a K-MAX in action. That's a really unique aircraft:
[https://en.wikipedia.org/wiki/Kaman_K-
MAX](https://en.wikipedia.org/wiki/Kaman_K-MAX)

------
pxeboot
Watching the cable get run would be much more interesting.

~~~
monk_e_boy
PEAK 2 PEAK Gondola - Cable Installation

2:12
[https://www.youtube.com/watch?v=IHsF1kRKEV0](https://www.youtube.com/watch?v=IHsF1kRKEV0)

TLDR; Spool out cable (rope), lift the end up with helicopter drape it over
the sheave train (the wheels on the cross arm) pull out more rope, etc

~~~
salimmadjd
How do they tie the cables together? To get 9KM of cable they must use
multiple spools and somehow tie them together. I'm curious how they're joined
so they do not become the "weakest link in the chain" and are not too bulky
for the wheels.

~~~
lflux
It's spliced like any other rope, you can see this in action here:
[https://youtu.be/5itSfxJoXY4?t=183](https://youtu.be/5itSfxJoXY4?t=183)

The splice for the Vail lift is about 300 feet long apparently.

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tschellenbach
Ski-resort tycoon, now that would be an awesome game :)

~~~
mstade
I'd pay money for this!

~~~
clarkm
You're in luck:
[https://en.wikipedia.org/wiki/Ski_Resort_Tycoon](https://en.wikipedia.org/wiki/Ski_Resort_Tycoon)

I used to play it quite a bit when it first came out.

~~~
mstade
You Sir will be the end of me, or at least my productivity. Thanks for the
tip! :o)

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tenaciousJk
I never knew I always wanted to know. Neat.

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BenjaminDyer
Thats quite fascinating to watch, however I'm not sure if I missed it but I
didn't see the tower being earthed. Those installers must have some impressive
protection in place.

I used to be a volunteer on an emergency lifeboat crew, we would do a lot of
drills with a man on a winch and the first rule is, don't touch until he's
earthed. Helicopters pick up a hell of a lot of static electricity so you
normally see a small earthing line hanging below the man on the end of the
line.

One time we were practicing fast recovery, the boat and the helicopter doing
crew exchange at high speed. We screwed it up and the static charge blew a
hole in the side of the boat!

~~~
sidegrid
Where are you from? Never heard anyone use earthed instead of grounded.

~~~
BenjaminDyer
UK, Electronic Engineer originally. We tend to use both terms I think.

TIL: Not everyone uses the term earthed!

------
pcarolan
Compare this to the cost of installing light/medium rail in your city. Why we
dont install these in every city baffles me. You could run them right
alongside buildings.

~~~
ethagknight
Because they can only haul 2,000 people per hour, with limited travel lengths
and single point termini

~~~
Fezzik
A slight modification: though slow, they can have multiple un/loading points.
The main gondola at Whistler has a mid-mountain loading point along with a top
and bottom un/loading point. The Peak to Peak Gondola only has a loading point
at each end because it's crossing a giant chasm.

Your point stands though: gondolas are probably not a great form of transport.
That said, I have no idea what the speed limits would be for a gondola that
was designed for speed.

~~~
pcarolan
They have those unloading points because they are able to take them off of the
cable while loading and unloading. We don't design these for cities, but we
could. This means loading/unloading could be coordinated across multiple nodes
and you could even switch tracks which takes care of the fixed distance
problem. Detachable chairlifts can do 12mph which is faster than many city
buses.
[https://en.wikipedia.org/wiki/Detachable_chairlift](https://en.wikipedia.org/wiki/Detachable_chairlift)

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jacquesm
Judging by the curve of the cable the load is suspended from they're not
exactly slacking either while moving it to the drop site.

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zyztem
TL;DR: with helicopter, one section at a time

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rattray
Mods: should perhaps be labeled with (2011)

Fun video

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mmmpop
All that work and still 25 minute lines on a powder day...

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AlphaWeaver
[video] (2011)

~~~
jonknee
Because ski lift installation has changed since 2011?

~~~
grzm
It's common on HN to include the year if it's not from the current year. It's
not a reflection on the submission's appropriateness: it's just additional
information many find useful, just as the [video] tag is.

