Some problems on Pallivacinni Today
#1
Posted 13 January 2008 - 09:03 PM
Title edit by forum administrator – 1/15/07
"Today's problems cannot be solved by the level of thinking that created them." -Albert Einstein
#2
Posted 14 January 2008 - 04:35 PM
This post has been edited by aug: 14 January 2008 - 05:05 PM
#3
Posted 14 January 2008 - 06:24 PM
#4
Posted 14 January 2008 - 09:21 PM
"Today's problems cannot be solved by the level of thinking that created them." -Albert Einstein
#5
Posted 14 January 2008 - 09:25 PM
skierdude9450, on Jan 14 2008, 09:21 PM, said:
I would think this makes a difference because that means that the downhill side is shorter and has fewer chairs, and therefore less weight. It probably is not that significant of a weight difference, however.
Liftblog.com
#6
#7
Posted 15 January 2008 - 10:56 AM
Skier, on Jan 14 2008, 10:25 PM, said:
Unless I am missing some thing ...... both sides of a conventional lift MUST be of equal length.
#8
Posted 15 January 2008 - 11:10 AM
Skier, on Jan 14 2008, 10:25 PM, said:
Skier..... What the hell are you saying?
#9
Posted 15 January 2008 - 01:41 PM
#10
Posted 15 January 2008 - 02:22 PM
Skier, on Jan 14 2008, 11:25 PM, said:
It seems like that would make a perpetual motion machine
This post has been edited by AlphaBet: 15 January 2008 - 02:23 PM
#11
Posted 15 January 2008 - 02:39 PM
vt3pinandy, on Jan 15 2008, 02:41 PM, said:
I have only seen this "flying return line" on bottom drives - because the return line is being pulled downhill and wants to be straight. AP- have you seen one on a top drive?
I would think this makes a difference because that means that the downhill side is shorter and has fewer chairs, and therefore less weight. It probably is not that significant of a weight difference, however.
As AP has stated, because the uphill cable follows the terrain (restrained) and the downhill cable is allowed to fly (straighten), the downhill line is actually shorter. Being familiar with the Pali, I would estimate the difference on a 3500 foot long lift to be about 10 feet - not enough to effect the number of carriers on either side or an unbalanced line.
9450 - your information source?
Dino
#12
Posted 15 January 2008 - 03:37 PM
"Today's problems cannot be solved by the level of thinking that created them." -Albert Einstein
#13
Posted 15 January 2008 - 03:57 PM
skierdude9450, on Jan 15 2008, 04:37 PM, said:
As u know you have to be able to backup what you say around here. So that is why Dino is asking for a source. If u dont want to make it public just send him a pm with the name of the techie that you were chatting with.
#14
Posted 15 January 2008 - 05:19 PM
Dennis.
#15
Posted 15 January 2008 - 05:46 PM
#16
Posted 16 January 2008 - 12:43 AM
As all lifts are designed to a tensioning force taking into account the coefficient of friction of the bullwheel liner to the rope,(as well as other variables) on lifts that are close to this design value, you can get slippage in certain situations. (some people have adjusted the plus and minus % values on the tension panel) this has also caused problems. I also know of a rope that was lubed, too late and too much in the fall, that had slippage and the rope and liner had to be cleaned.
So whether the system is a top drive pulling the load up the hill or a bottom drive pushing the load up, should make no difference in the operation. By the way look at your tensiong system, from empty to having a full load, pulling or pushing the load (newer drive tension systems) you will not have an unbalanced line, at the most you might see 1 meter of difference x 2 so approximatly 6 feet of sag (not much) over the complete side, not enough to unbalance your line and cause slippage even if design tolerances are close, and yes most of the sag will be near the bottom of the lift.
So the friction between the bullwheel liner and the rope is the driving force, (no pun intended) anything we do to change this value will effect the system including, allowing ice to build up between the rope and bullwheel liner.
#17
Posted 16 January 2008 - 06:35 AM
#18
Posted 16 January 2008 - 11:50 AM
chasl, on Jan 16 2008, 01:43 AM, said:
As all lifts are designed to a tensioning force taking into account the coefficient of friction of the bullwheel liner to the rope,(as well as other variables) on lifts that are close to this design value, you can get slippage in certain situations. (some people have adjusted the plus and minus % values on the tension panel) this has also caused problems. I also know of a rope that was lubed, too late and too much in the fall, that had slippage and the rope and liner had to be cleaned.
So whether the system is a top drive pulling the load up the hill or a bottom drive pushing the load up, should make no difference in the operation. By the way look at your tensiong system, from empty to having a full load, pulling or pushing the load (newer drive tension systems) you will not have an unbalanced line, at the most you might see 1 meter of difference x 2 so approximatly 6 feet of sag (not much) over the complete side, not enough to unbalance your line and cause slippage even if design tolerances are close, and yes most of the sag will be near the bottom of the lift.
So the friction between the bullwheel liner and the rope is the driving force, (no pun intended) anything we do to change this value will effect the system including, allowing ice to build up between the rope and bullwheel liner.
As much as I regret in correcting the previous statment ,I must. (So whether the system is a top drive pulling the load up the hill or a bottom drive pushing the load up, should make no difference in the operation.) Regardless of where the drive sheave is on any lift using a rope, you must pull. In a bottom drive the bottom BW pulls the Haul rope up and around the top BW. One of the most compelling reasons to have a top drive is the increased tension on the top BW vs. the bottom BW. One of the dis-advantages of a top drive is the surge that is created in the slack line going down the hill to the return (bottom) terminal when the lift is slowed or stopped. In my observations over the years the surge in bottom driven lifts is less than in top driven lifts .
#19
Posted 16 January 2008 - 12:28 PM
Dino
#20
Posted 05 February 2008 - 06:38 PM
Lift Dinosaur, on Jan 15 2008, 02:39 PM, said:
I'm pretty sure Chair 21 (Yan FGT) at Mammoth Mountain has a flying return line and is a top drive.
Eric
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