14 replies to this topic

[Kicking Horse]

I'm wondering something. With the amount of stops that happen on a lift. Is it possible for a HS lift to stop the chairs in the terminal but keep the line moving until the chairs stack up?

IE if someone falls and the operator can stop the chairs in the terminal but allow the line to keep moving @ a slower speed until the chairs stack up in the terminal. Is that even possible?

If i need to make this clearer let me know.

[SkiBachelor]

No it's typically not possible to do this since the cadence system is most of the time connected to the bullwheel. That way if the lift is moving, the cadence system will be too. However, on some lifts like the Doppelmayr HSQs, there is a spacing clutch and if that were to fail, the carriers would start to pile up in the terminal. I saw this at Mt. Bachelor a few years ago on the Northwest Express.

[Peter]

Forest Queen Express at Crystal Mountain had this problem one day last season, the chairs stacked up in the terminal. The chairs decelerated, stopped, and three lift ops were pushing the chairs through the terminal. Then right near the loading point, the chairs would start moving again. All day the chair was off and on with this problem and they kept it open! Some chairs were really close together, and some were really far apart.

[Kicking Horse]

I'm thinking they could build it in / make it an option.

What do the lift techs think of this idea? Other then it throwing Chair spacing off.

[SkiBachelor]

What would be the point though Jeff? Why not just slow the lift down or stop it rather than having to deal with a spacing issue that could take 2 hours to get everything back to normal?

I should also mention that this could mess up the lifts designed load capacity since one side could have more carriers than on the other side. For example, what if 3/4 of the carriers were on the uphill side while only 1/4 were on the downhill side. See the problems the lift could run into? Some fix grips lifts actually will shut down and will run extremely slow if they become overweighted. Not sure about detachables since they have bigger motors but I think it could still mess things up a bit. Especially while loading the lift. People would have less time to get to the loading zone which would then cause more lift down time. Sorry Jeff, but I don't think it's that great of an idea.

[SkiBachelor]

However, the UNI-G maybe the UNI-GS and the Leitner HSQ terminals do have the ability to park the carriers in the terminal instead of having a chair parking rail.

[Aussierob]

If you had a really long terminal that had a straight slow section after the deceleration section you might be able to do it. You would need to have the slow section and turnaround powered by AC motors so that the chairs could be sped up and put back in place after they were slowed. It is technically possible but would be really expensive. Plus you need back up AC power and a whole bunch more machinery etc. The benefit wouldn't justify the cost.

[Mike]

Quicksilver at breck can (and does) stop chairs in the return terminal instantly if required. If the lift thinks that there is a possibility of a chair running off a gate, it will "quick stop" the chair while the haul rope is still moving. It does mess the spacing up a little but it doesn't screw the spacing up as bad as running a chair off a gate! We would typically adjust the chair right then and there or adjust it at the top of the lift with the spacing system.

Aussierob, on Apr 7 2006, 09:23 AM, said:

... Plus you need back up AC power and a whole bunch more machinery etc. The benefit wouldn't justify the cost.

There is a 480VAC diesel generator in the return terminal just for the reason you mentioned...

Poma experimented with using AC motors at the return but switched to DC because they needed more startup torque.

[liftmech]

I don't see any benefit. I'm picturing all the additional machinery and control electronics and all I see is a maintenance headache waiting to happen.

SkiBachelor, on Apr 6 2006, 10:00 PM, said:

I should also mention that this could mess up the lifts designed load capacity since one side could have more carriers than on the other side. For example, what if 3/4 of the carriers were on the uphill side while only 1/4 were on the downhill side. See the problems the lift could run into? Some fix grips lifts actually will shut down and will run extremely slow if they become overweighted.

I agree with your first statement but not with your second. I've run lifts with no carriers at all on one side (after a rope replacement while putting chairs on) and there has been no problem. Lift drives automatically adjust for differential loads, i.e. a full load uphill and empty carriers downhill. But I'll agree that having wierd spacing would be problematic for lightly-loaded towers, perhaps to the point of a derail.

[SkiBachelor]

The reason why I said some lifts would shut and slow down is because the Catskinner at Blackcomb does when it's overloaded.

[Mike]

SkiBachelor, on Apr 9 2006, 05:43 PM, said:

The reason why I said some lifts would shut and slow down is because the Catskinner at Blackcomb does when it's overloaded.

sounds like a design problem.

[WBSKI]

its totally possible, but it cant be stopped for long. Example: Glacier Express, Lake Louise in Summer. Its a HS quad yet they stop the chairs in the terminal for say 5 seconds for people to get on and then they run the chairs in the terminal fast. I was impressed when i saw this, got a video clip of it. They didnt have any spacing issues although they clearly increased the chair spacing on the line.

[Kicking Horse]

5 secs is all you need sometimes.

[liftmech]

Mike, on Apr 9 2006, 07:43 PM, said:

sounds like a design problem.

Yes it does. One would think it would be impossible to 'overload' a lift without triggering an overcurrent fault and shutting it down; if that happened one would want to fix the problem.

[Aussierob]

SkiBachelor, on Apr 9 2006, 04:43 PM, said:

The reason why I said some lifts would shut and slow down is because the Catskinner at Blackcomb does when it's overloaded.

We had a problem with the old Yan drive that we couldn't resolve. We wound up running it as a double. The lift got an all new drive and controls in 2005. (same as Cystal got in 2004). We are doing Magic this year and olympic next year.