Downsides to High Speed Lifts?
Actually, it can have something to do with how fast the queue moves, but of course it will depend on chair count as well. Related variables, all part of the overall system...
Thanks for the pointer to skilifts.org in #31 -- there's a whole pile of really interesting info there, including capacity stats for quite a few lifts. Looking through a bunch of them, it looks like moving from fixed grip to detachable can increase capacity, but it won't always.

And while we're talking wire ropes, let's talk about lay. Most detachable lifts use lang-lay wire ropes, while most fixed grips use a regular-lay. Because a regular lay has the wires of the strand laid opposite the direction of the stands upon the core, there is more resistance to grip slippage.
Well, maybe that's not "fun" to all of you. But I do it............
You'll also notice most fixed grips use a 6x19 wire rope, while detachables use a 6x37. But I'm gonna quit while I'm ahead...

How can this not be fun? What else is there to do on the lift other than stare at the cable? I always have my eye out for the splice...
I had noticed the difference in cables between fixed and detachables. I did not know that detachables used Lang Lay. My experience with cordage was that most was right hand regular lay, (except hawsers, which are usually left hand regular). I didn't know that Lang lay was so prevalent.
One question that I've had for some time is whether the "handedness" of the rope is correlated with the direction of the lift - ie is there any advantage to using, say, righthand lay on clockwise lifts? Anybody know?

How can this not be fun? What else is there to do on the lift other than stare at the cable? I always have my eye out for the splice...
I had noticed the difference in cables between fixed and detachables. I did not know that detachables used Lang Lay. My experience with cordage was that most was right hand regular lay, (except hawsers, which are usually left hand regular). I didn't know that Lang lay was so prevalent.
One question that I've had for some time is whether the "handedness" of the rope is correlated with the direction of the lift - ie is there any advantage to using, say, righthand lay on clockwise lifts? Anybody know?
You know, I was just wondering the same thing. I'll have to ask someone and find out. I haven't payed enough attention to correlate the lay with the direction of travel.
~Patrick Torsell
Director, Mogulskiing.net

Let me debunk a common misconception while this thread is still young. Detachable (high speed) chair lifts usually do not have a higher capacity than their fixed grip counterparts (aka... there aren't any more people on the hill). The difference in speed is compensated for by wider chair spacing. Detachable lifts must have a wider chair spacing so that the chairs do not bunch up in the terminals during loading while the chairs are moving slowly.
The industry standard capacity for a quad is 2400pph (people per hour), regardless of whether it is detachable or fixed grip. The length of ride is different, but the number of people being put on the mountain is exactly the same. Detachable quads do allow for a higher capacity under special conditions, but it is rare to see a detach with a capacity higher than 2400pph.
It's all one big mathematical equation, in reality. For those really interested in the technical end of ropeway operations, consider the following:
Where:
C= capacity in pph (people per hour)
P = passengers per carrier
T = loading interval in seconds (time between each chair passing the load board)
R = rope speed in fpm (feet per minute)
-and-
S = carrier spacing in feet
C = (60 * P * R) / S
T = (60 * S) / R ---or--- T = 3600 / (C / P)
So let's look at a theoretical situation. Lift "A" is a fixed grip quad running at the maximum legal speed of 400fpm. Lift "B" is a detachable quad with a maximum design speed of 1200fpm. Both lifts have an industry-standard comfortable loading interval of 6 seconds.
Lift "A"
First, we need to determine the chair spacing based on T = (60 * S) / R
6sec = (60 * S) / 400fpm
2400 = 60 * S
S = 40ft
Now, we can plug in our chair spacing to determine our capacity based on C = (60 * P * R) / S
C = (60sec * 4people * 400fpm) / 40ft
C = 2400pph
Lift "B"
We'll start by calculating chair spacing as we did with Lift "A"
6sec = (60 * S) / 1200fpm
7200 = 60 * S
S = 120ft
Again, we move on to capactity
C = (60sec * 4people * 1200fpm) / 120ft
C = 2400pph
That's theoretical, or, design capacity. Actual capacity is a whole 'nuther ballgame (based on loading efficiency, stops, slows, percentage of load, etc.).
[/lift geek]
Something might be wrong here unless Hunter Mountain Lied... Check this out. Express is 3000 PPH and Fixed grip is 1800PPH
Skiing combines outdoor fun and knocking trees down with your face. ~Dave Barry
Not only that, but ski areas can "adjust" capacity by adding or removing chairs, or by running at higher or lower speeds (dependent, of course, on state law).
A detachable quad could possibly have a capacity of 3,000pph, but that is quite a stretch. I've seen several at 2,800pph, but not 3,000pph. Note that in my post, I said that it is rare to see a detachable quad at more than 2,400pph, but that implies that there are specific instances of higher capacity.
~Patrick Torsell
Director, Mogulskiing.net
This matches the SnowLite Express on SkiLifts.org when it was installed in 1987. Anything over 2400 people per hour (pph) in a quad means they unload a quad chair faster than every 6 seconds.
4 people x (60 / 6 seconds) x 60 = 2400 pph
http://www.skilifts.org/old/install_na1987.htm
fixed chairs require about one tenth the maintenance as detachables, so less overhead.

Quote:
This matches the SnowLite Express on SkiLifts.org when it was installed in 1987. Anything over 2400 people per hour (pph) in a quad means they unload a quad chair faster than every 6 seconds.
4 people x (60 / 6 seconds) x 60 = 2400 pph
http://www.skilifts.org/old/install_na1987.htm
I'm not sure about NY, but Colorado has a state law limiting lift loading rate to no more than ten chairs per minute (6 seconds per chair) As you demonstrate, that rate translates into 2400 people per hour for a quad. In order to reach 3000 people per hour, they'd have to load 12.5 chairs a minute or a chair every 4.8 second. My hunch is that the chair is capable of running that fast, but they don't run it like that because the patrons wouldn't be able to keep up with it.
Note that there are 13 lifts on the list at http://www.skilifts.org/old/install_na1987.htm with stated capacities greater than 2400 per hour. I'lll bet none of them have ever reached this rate in actual operation.
BTW, I ridden lifts that load faster than ten per minute, but they're rare. And they're noticeably different - as in "holy shit, the chairs come by so fast I barely have time to get on". That extra second makes a big difference.

I'm not sure about NY, but Colorado has a state law limiting lift loading rate to no more than ten chairs per minute (6 seconds per chair) As you demonstrate, that rate translates into 2400 people per hour for a quad. In order to reach 3000 people per hour, they'd have to load 12.5 chairs a minute or a chair every 4.8 second. My hunch is that the chair is capable of running that fast, but they don't run it like that because the patrons wouldn't be able to keep up with it.
Note that there are 13 lifts on the list at http://www.skilifts.org/old/install_na1987.htm with stated capacities greater than 2400 per hour. I'lll bet none of them have ever reached this rate in actual operation.
BTW, I ridden lifts that load faster than ten per minute, but they're rare. And they're noticeably different - as in "holy shit, the chairs come by so fast I barely have time to get on". That extra second makes a big difference.
snowbird would run the high speed lifts noticeable faster during midweek. I would venture to say that p-dog and MBX would meet 2400 skiers per hour when it was crowded midweek.
"Trading the future for the moment, one powder turn at a time"
pbfootnit.blogspot.com/ <<< the start of something good!
like i already mentioned in this thread... skilifts.org says that the old shirley quad at squaw had a capacity of 3,000 PPH.
that was replaced by a 6-pack two years ago, which presumably has an even higher capacity!
With a good liftie and a well designed line-ramp-maze-singles fill line, the pph can higher due to spacing and speed. but all those parts have to be in place.
In theory, yes. But show me a real-life situation where you're loading 4 people at a time every 5 seconds. Probably not going to happen. Any potential gain in capacity would disappear due to a drop in efficiency (for slows and stops when people don't make it from "wait here" to "load here" in time!). Even with a good lifty at the wait board and a good lifty at the load board, it's not very feasible.
~Patrick Torsell
Director, Mogulskiing.net

In theory, yes. But show me a real-life situation where you're loading 4 people at a time every 5 seconds. Probably not going to happen. Any potential gain in capacity would disappear due to a drop in efficiency (for slows and stops when people don't make it from "wait here" to "load here" in time!). Even with a good lifty at the wait board and a good lifty at the load board, it's not very feasible.
In Europe you see conveyor belts on loading. Its very efficient. This is more for six packs then it is for quads. I would imagine the conveyor belt reduces lift stop time and may make it possible to reduce time between chairs.
The other improvement is lift line control. For example if on a quad the attendants work out who goes on what chair right before you get on the chair lift, this will result in a lot of time stopping the lift. If the attendants move back the area where you decide which customers are going to ride together so that at least 3 quad chairs or 12 customers are all matched up in the lift line and have a straight walk to the loading area, then the lift will not have to be stopped as much. Also Windham put in a HS quad with a 90 degree turn in the lift line right before you got on the lift a few years ago. This was a very bad design and resulted in a lot of time stopping the HS Quad lift. Windham was under brand new management at the time. It was obvious the Windham management had a lot to learn.
Edited by catskills - 11/7/09 at 4:51am
There's the hypothesis. Do we have empirical data (or anyway, perceptual data) to support it?

Then there's the question of cold. A long grip-lift ride is colder (length of exposure) than a short detachable ride; muscles cool, and therefore (I hypothesize) the perception of fatigue is greater. One reason high-speed lifts are popular, marketing aside, is that skiers spend less time aloft, motionless in a chilling wind -- not only pleasanter, less fatiguing.
There's the hypothesis. Do we have empirical data (or anyway, perceptual data) to support it?
I don't have any hard data to prove it, but it makes perfect sense to me.
Skiing combines outdoor fun and knocking trees down with your face. ~Dave Barry

Then there's the question of cold. A long grip-lift ride is colder (length of exposure) than a short detachable ride; muscles cool, and therefore (I hypothesize) the perception of fatigue is greater. One reason high-speed lifts are popular, marketing aside, is that skiers spend less time aloft, motionless in a chilling wind -- not only pleasanter, less fatiguing.
There's the hypothesis. Do we have empirical data (or anyway, perceptual data) to support it?
Smell that? Winter's coming!

There IS however a downside to making them too comforting. Parsenns bowl at Mary Jane comes to mind. The high speed six pack means it will be tracked out in minutes. If they had put a poma in, only the core would be up there and the freshies would last alot longer. Think of the High T at Breck which brings you to the horseshoe bowl. (although the imperial chair brings you higher) That life can be pretty tough on a really windy day (when the imperial would be closed anyways) and will never close for a blizzard either.
Actually a lot of people should give up skiing.
Edited by Jer - 11/7/09 at 6:28pm
No one cares that you tele.
Skiing combines outdoor fun and knocking trees down with your face. ~Dave Barry
I fear I've moved beyond "avid" to obsessed...but I've found all I really NEED is skins and dynafits. Don't get me wrong, I like chairlifts as much as the next guy, but when it comes down to it, I get a lot more untracked powder turns when the lifts ain't running.

