Detachable vs Fixed Grip Lifts

[Brownski]

I have tried and failed to explain how detachable grips work so many times. All I get back is a blank stare. Watch this a couple times and you’ll get it

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[MarzNC]

This video seems to be a good introduction for people who know nothing about chairlifts from a mechanical standpoint.

March 22, 2025

 

[Ripitz]

Hey @snoloco, Berkshire East has a carpet loader and a detachable right next to each other with nearly identical length. If everything is operating at full speed and capacity, which one moves the most people per hour? I assume the detachable T-bar Express has a faster ride time. It seemed quicker when I was there, but I did not record the ride time. Quicker doesn’t necessarily mean more people per hour. Does the chair spacing create greater uphill capacity in this case? The Summit chair is known to be somewhat unreliable and the carpet loader I believe was a later addition to try and speed things up. What are your thoughts about reliability and efficiency with this scenario?

 

[snoloco]

-The Summit Quad has a theoretical capacity of 2400 per hour at a speed of 500 fpm.
-The T-Bar Express has a theoretical capacity of 1800 per hour at a speed of 1000 fpm.
-The Summit Quad had the loading carpet right from the start, and every video of the lift that I can find shows it in use.

-This video of the Summit Quad has a speed of 440 fpm, which would result in a capacity of 2112 per hour.

-This video of the T Bar Express has a speed of 750 fpm, and results in a capacity of 1350 per hour.

-This is not really a question of the benefits or drawbacks of loading carpets, but rather a question of speed vs chair spacing. There are two methods for how to design a lift's capacity, either close chair spacing and slower speed, or wide chair spacing and higher speed.

-With the first method, the chairs are spaced very close together, so close in fact, that the lift can't run at full speed during normal operations, as there would be far too many loading/unloading issues, resulting in excessive stops and slows. The benefit to this is that you can always achieve the highest capacity by setting the speed as fast as possible without causing excessive stops and slows. In other words, a sweet spot can be found. This is usually a loading interval of 6-7 seconds for quads, and 7-8 seconds for 6 packs. This also means that in situations where a lift has to run at a slower speed, such as due to wind, the capacity is still halfway decent. One drawback to this strategy is that it's more chairs to inspect and maintain. Another drawback is that the lift will always have a longer ride time, as it is never operated at full speed.

-With the second method, the chairs are spaced far enough apart to create a comfortable loading interval at full speed, with the intention of running the lift at full speed whenever not limited by weather or mechanical issues. The main benefit to this strategy is a faster ride time. Another benefit is there are fewer chairs to inspect and maintain. A major drawback is that lift always has to run at full speed to get a decent capacity. If there is any situation where the lift has to run at reduced speed, then the capacity really suffers. It also means that possible capacity is being left on the table. If the lift is running at full speed and having no loading or unloading issues, that's great, but it could possibly run at an even faster interval with the same result.

-I don't want to be too harsh on Berkshire East, as the T-Bar Express is their first detachable, and a significant upgrade for the resort, but I actually believe the design for the capacity of this lift is incredibly flawed. It's relatively short for a detachable, so speed isn't actually all that important. Even if it's running far below its top speed, at say 700-800 fpm, as long as it's running significantly faster than a fixed grip, it's likely fine in most skier's eyes. Now I would find that speed to be very slow, but that's only because I have ridden a lot of lifts, know what the top speeds are, and I'm a stickler for maximizing capacity. The problem is the chair spacing. Spacing a lift for only 1800 per hour would typically be indicative of a lift designed using the second method, in that it is always expected to run at full speed. That isn't being done, which results in a capacity that would be considered low for even a triple chair. I don't think the backup lift should have significantly higher capacity than the primary lift, which is what most people want to ride. It needed a theoretical capacity of 2600-2800 per hour to get a decent throughput at the speed range they are running it at.

 

[Ripitz]

Thank you for the insight Sno. Very good explanation. It is interesting to see the two lift designs side-by-side, which makes for an easy comparison. I had a hunch the Summit Chair had more uphill capacity. Carpet loading fixed grips for the win!

 

[Ripitz]

This video of the Summit Quad has a speed of 440 fpm, which would result in a capacity of 2112 per hour.

This video of the T Bar Express has a speed of 750 fpm, and results in a capacity of 1350 per hour.

The videos are helpful, thank you for posting them.

The ride time for the Express is around 4 minutes and the Summit is 7. That’s quite a difference.

It seems if the goal is to move more people out of the base area the Summit is the winner. If you want quicker laps the win goes to the Express.

 

[Harvey]

-The Summit Quad has a theoretical capacity of 2400 per hour at a speed of 500 fpm.
-The T-Bar Express has a theoretical capacity of 1800 per hour at a speed of 1000 fpm.
-The Summit Quad had the loading carpet right from the start, and every video of the lift that I can find shows it in use.

-This is not really a question of the benefits or drawbacks of loading carpets, but rather a question of speed vs chair spacing. There are two methods for how to design a lift's capacity, either close chair spacing and slower speed, or wide chair spacing and higher speed.

-With the first method, the chairs are spaced very close together, so close in fact, that the lift can't run at full speed during normal operations, as there would be far too many loading/unloading issues, resulting in excessive stops and slows. The benefit to this is that you can always achieve the highest capacity by setting the speed as fast as possible without causing excessive stops and slows. In other words, a sweet spot can be found. This is usually a loading interval of 6-7 seconds for quads, and 7-8 seconds for 6 packs. This also means that in situations where a lift has to run at a slower speed, such as due to wind, the capacity is still halfway decent. One drawback to this strategy is that it's more chairs to inspect and maintain. Another drawback is that the lift will always have a longer ride time, as it is never operated at full speed.

-With the second method, the chairs are spaced far enough apart to create a comfortable loading interval at full speed, with the intention of running the lift at full speed whenever not limited by weather or mechanical issues. The main benefit to this strategy is a faster ride time. Another benefit is there are fewer chairs to inspect and maintain. A major drawback is that lift always has to run at full speed to get a decent capacity. If there is any situation where the lift has to run at reduced speed, then the capacity really suffers. It also means that possible capacity is being left on the table. If the lift is running at full speed and having no loading or unloading issues, that's great, but it could possibly run at an even faster interval with the same result.

-I don't want to be too harsh on Berkshire East, as the T-Bar Express is their first detachable, and a significant upgrade for the resort, but I actually believe the design for the capacity of this lift is incredibly flawed. It's relatively short for a detachable, so speed isn't actually all that important. Even if it's running far below its top speed, at say 700-800 fpm, as long as it's running significantly faster than a fixed grip, it's likely fine in most skier's eyes. Now I would find that speed to be very slow, but that's only because I have ridden a lot of lifts, know what the top speeds are, and I'm a stickler for maximizing capacity. The problem is the chair spacing. Spacing a lift for only 1800 per hour would typically be indicative of a lift designed using the second method, in that it is always expected to run at full speed. That isn't being done, which results in a capacity that would be considered low for even a triple chair. I don't think the backup lift should have significantly higher capacity than the primary lift, which is what most people want to ride. It needed a theoretical capacity of 2600-2800 per hour to get a decent throughput at the speed range they are running it at.

Clear, insightful analysis. Thank you @snoloco.

 

[gorgonzola]

When we stopped there this year on the way home from our Jay Indy trip it was a very busy day with 5-6" pow overnight and races going on. There were significant lines for the Express and the Summit was only a few chairs deep and and net time much faster. I found it very interesting that people would rather wait in line for the high speed than do a little hoofing around to the shorter lines...

 

[Brownski]

I found it very interesting that people would rather wait in line for the high speed than do a little hoofing around to the shorter lines...

“High speed” has some kind of magic effect on casual skiers’ brains. I heard Jim Schafer once reference a statistic that adding a high speed quad to your lift fleet increases pass sales by about 20%. This was when BE and Cat still didn’t have any detachables. I’m still mostly against them

 

[MarzNC]

“High speed” has some kind of magic effect on casual skiers’ brains. I heard Jim Schafer once reference a statistic that adding a high speed quad to your lift fleet increases pass sales by about 20%. This was when BE and Cat still didn’t have any detachables. I’m still mostly against them

Depends on the situation.

Timberline in WV has great snow and terrain for the region. There used to be an old double to the summit. Ride time was 12 minutes, if you were lucky and it didn't stop. When the Perfect family took over, they replaced it with a detachable 6-pack. Ride time went to 4 minutes. From the top, it's possible to access 100% of the terrain, both groomed trails and off-piste (when there is enough snow). There is no redundancy.

Midweek the 6-pack looks like overkill. But the 4-min ride makes doing laps really, really run. The market for Timberline includes Pittsburgh, Washington DC, northern VA, and eastern OH. Fair to say that have a high speed life has probably increased the number of people who make the trek to WV for midweek skiing.

Having the 6-pack helps a lot on weekends and holidays. At least that's what I've read on DCSki.

Wachusett went to high speed lifts quite a while ago. Even for the green trails, which are relatively long. For their market, it works very well. Beginners get more time on snow versus riding a slow fixed-grip lift. Midweek seniors are happy doing some laps for a couple hours in the morning. Kids who come in the afternoon get in more runs. Night skiing is a big deal and worth the drive with fast lifts.

I appreciated the high speed lift to the top of Wildcat when I went to check it out. Probably wouldn't have bothered to go back if that had been a fixed-grip lift with a 10+ minute ride. It's cold riding a lift in New England. ;-)