Today at Mountain Creek, this happened. The weather was freezing rain and ice was building up on lift chairs and on my coat. I came down Southern Sojourn to the South Peak trail pod. When the South Peak Express came into view, I noticed that it was not moving, but there were people on it. When I got to the bottom, the lift still was not moving, so I got on the Bear Peak Express which was still loading. It was running at reduced speed. Earlier in the day it was running at full speed. After I took my run on Bear Peak, the South Peak Express still was not running, so I took another run on Bear Peak. When I got to the bottom after this run the South Peak Express was running at reduced speed, but was not loading. I asked the liftie why it was closed and he said that it was due to ice and that the lift was running on diesel. He said that the lift would hopefully be loading soon. One more run on Bear Peak and I saw that they were folding seats and taking down all the barriers in the corral. Then the lift stopped running and I did not see it start again. I do not know if the lift ever reopened since I had to go back to Vernon Peak, but the lift was not open when I left. Are the issues listed here common effects of icing on ski lifts?
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Ice and its Effect on Lift Operations
Started by snoloco, Jan 05 2014 03:55 PM
9 replies to this topic
#2
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Posted 06 January 2014 - 04:39 AM
Related question, what sorts of precautions do ski areas take for temperatures like the Upper Midwest experienced this week? Can't be good for business having wind chills in the -50s
- Tyler
West Palm Beach, FL - elev. 9 feet
West Palm Beach, FL - elev. 9 feet
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Posted 06 January 2014 - 10:31 AM
To answer Tyler's question:
Even thou the temps were not bad on Saturday or Sunday (Forecasters totally missed the mark) most of the areas in the Twin Cities closed early. I believe all of the local areas are closed today and most are opening later in the day tomorrow or Wednesday after the winds die down. What they are doing from a maintenance standpoint I have no idea.
Even thou the temps were not bad on Saturday or Sunday (Forecasters totally missed the mark) most of the areas in the Twin Cities closed early. I believe all of the local areas are closed today and most are opening later in the day tomorrow or Wednesday after the winds die down. What they are doing from a maintenance standpoint I have no idea.
This post has been edited by MNSkier: 06 January 2014 - 10:32 AM
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Posted 06 January 2014 - 05:35 PM
snoloco, on 05 January 2014 - 03:55 PM, said:
Today at Mountain Creek, this happened. The weather was freezing rain and ice was building up on lift chairs and on my coat. I came down Southern Sojourn to the South Peak trail pod. ...
I am a ski patroller not a mechanic, so I will not speculate about the Mountain Creek specific operational decisions. However, I have been a patroller for 25 years, and a member of this forum for quite a while and have read a lot, so now know enough about ski lifts to help you form an answer. All chair lifts, high speed and regular speed have devices in place on the tower wheel assembly (the assembly is called a sheave) called brittle bars. The brittle bar is meant to break if the chair lift cable derails or is about to derail off a tower. The brittle bar is connected to low voltage electrical circuits (circuits on every tower), and the circuits are all connected to an electrical smart panel that will shut down the ski lift if there are any circuit faults (brittle bars breaks) on any sheave assembly anywhere on the ski lift. The smart panel helps lift mechanics isolate circuit faults to a specific tower and sheave assembly.
All modern ski lifts, of every type (T-bars, chair lifts, gondolas, trams, etc) have brittle bars in place to detect cable derailing. The danger of running a ski lift during a freezing rain event is that ice could built up and freeze the brittle bar in place such that the circuit will not fault, even if the brittle bar does break, so potentially you could have a derailment due to ice, and the lift would not shut down quickly enough to prevent injury to riders. Or the ice could build up and cause a derailment, the brittle bars break properly, and the lift shuts down properly, but now restart cannot happen, and the chair will now need to be evacuated under emergency diesel power. Derailments are a big pain in the ass for everyone, even if no one gets hurt
*** Comment added Jan 7,2014. Please see member Aug's comment on this topic. My answer as first edited was a little bit wrong, so note that Aug says that modern brittle bars are designed and built to withstand icing. Aug's comments about rope slippage on high speed lifts during icing events was also a learning piece for me.. I stand corrected. - end of Jan 7 ,2014 correction ***
The Mountain Creek Jan 5,2014 freezing rain event: You would have to ask the local operators why they slowed the lifts down, but the most obvious answer would be to lessen the chance of derailment of lift. Some resorts keep the lifts running at low speed during ice events, even if there are no people on the lift, just to lessen the rate of ice buildup that might occur on a stopped lift.
We had a wide spread freezing rain event in Ontario Canada on the morning of Friday Dec 20,2013 that began in the morning and went all day. I was skiing that day. Our low speed lifts were still running (Devil's Glen, Glen Huron Ont - all our chairs are low speed) , however all other ski areas around us (Mount St Louis Moonstone, Blue Mountain,Alpine, Osler Bluffs) closed their high speed chairlifts early that day - mid day. We also closed 30 mins early because the electricity flickered at 3pm and we did not want to evacuate lifts under emergency diesel power. The resulting tree damage from this Dec20 Ontario freezing rain event caused wide spread power outages in Ontario that lasted six days in many places, and longer in some isolated pockets of Toronto Ont. It was a Christmas without power, heat or water for thousands of people in Ontario.
Does that help answer your question?
This post has been edited by Andy1962: 07 January 2014 - 05:59 AM
#7
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Posted 06 January 2014 - 07:13 PM
Freezing Rain is a show stopper for detachable lifts due to loss of friction between the Haul rope and the PTO sheaves in the terminals. Also due to loss of friction between the Grip traction plate and the conveyor tires. Some fixed grip lifts may have issues with the cable Tach in Icing situations. Modern brittle bar systems are NOT susceptible to icing issues since the devices are shielded from ice or moisture and are designed to run in a winter / icy environment .
"Maybe there is no Heaven. Or maybe this is all pure gibberish—a product of the demented imagination of a lazy drunken hillbilly with a heart full of hate who has found a way to live out where the real winds blow—to sleep late, have fun, get wild, drink whisky, and drive fast on empty streets with nothing in mind except falling in love and not getting arrested . . . Res ipsa loquitur (it speaks for it self). Let the good times roll." HT
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Posted 07 January 2014 - 08:03 AM
Good write up Andy. As a former Patroller and 25 year mechanic I will offer the following corrections below:
I am a ski patroller not a mechanic, so I will not speculate about the Mountain Creek specific operational decisions. However, I have been a patroller for 25 years, and a member of this forum for quite a while and have read a lot, so now know enough about ski lifts to help you form an answer. All chair lifts, high speed and regular speed have devices in place on the tower wheel assembly (the assembly is called a sheave) ...the 'tower wheel assembly" is called a sheave assembly. The individual wheels are called sheaves. called brittle bars. The brittle bar is meant to break if the chair lift cable derails or is about to derail off a tower...a brittle bar (sometimes called a break fork switch) can only detect a deropement. It cannot detect if it "is about to derail off a tower". Cable movement prior to a deropement is detected by a CPS (cable position switch) and are generally only found on detachable lifts. The brittle bar is connected to low voltage electrical circuits (circuits on every tower), and the circuits are all connected to an electrical smart panel that will shut down the ski lift if there are any circuit faults (brittle bars breaks) on any sheave assembly anywhere on the ski lift. The smart panel helps lift mechanics isolate circuit faults to a specific tower and sheave assembly.
All modern ski lifts, of every type (T-bars, chair lifts, gondolas, trams, etc) have brittle bars in place to detect cable derailing. The danger of running a ski lift during a freezing rain event is that ice could built up and freeze the brittle bar in place such that the circuit will not fault, even if the brittle bar does break, so potentially you could have a derailment due to ice, and the lift would not shut down quickly enough to prevent injury to riders. Or the ice could build up and cause a derailment, the brittle bars break properly, and the lift shuts down properly, but now restart cannot happen, and the chair will now need to be evacuated under emergency diesel power. Once you have a deropement, you should not run on electric OR emergency diesel backup UNTIL the deropement has been put back on the sheave assembly. After that you can run in either mode. Derailments are a big pain in the ass for everyone, even if no one gets hurt
*** Comment added Jan 7,2014. Please see member Aug's comment on this topic. My answer as first edited was a little bit wrong, so note that Aug says that modern brittle bars are designed and built to withstand icing. Aug's comments about rope slippage on high speed lifts during icing events was also a learning piece for me.. I stand corrected. - end of Jan 7 ,2014 correction ***
The Mountain Creek Jan 5,2014 freezing rain event: You would have to ask the local operators why they slowed the lifts down, but the most obvious answer would be to lessen the chance of derailment of lift. Some resorts keep the lifts running at low speed during ice events, even if there are no people on the lift, just to lessen the rate of ice buildup that might occur on a stopped lift.
We had a wide spread freezing rain event in Ontario Canada on the morning of Friday Dec 20,2013 that began in the morning and went all day. I was skiing that day. Our low speed lifts were still running (Devil's Glen, Glen Huron Ont - all our chairs are low speed) , however all other ski areas around us (Mount St Louis Moonstone, Blue Mountain,Alpine, Osler Bluffs) closed their high speed chairlifts early that day - mid day. We also closed 30 mins early because the electricity flickered at 3pm and we did not want to evacuate lifts under emergency diesel power. The resulting tree damage from this Dec20 Ontario freezing rain event caused wide spread power outages in Ontario that lasted six days in many places, and longer in some isolated pockets of Toronto Ont. It was a Christmas without power, heat or water for thousands of people in Ontario.
Does that help answer your question?
I hope this helps to clarify
Dino
Andy1962, on 06 January 2014 - 05:35 PM, said:
I am a ski patroller not a mechanic, so I will not speculate about the Mountain Creek specific operational decisions. However, I have been a patroller for 25 years, and a member of this forum for quite a while and have read a lot, so now know enough about ski lifts to help you form an answer. All chair lifts, high speed and regular speed have devices in place on the tower wheel assembly (the assembly is called a sheave) ...the 'tower wheel assembly" is called a sheave assembly. The individual wheels are called sheaves. called brittle bars. The brittle bar is meant to break if the chair lift cable derails or is about to derail off a tower...a brittle bar (sometimes called a break fork switch) can only detect a deropement. It cannot detect if it "is about to derail off a tower". Cable movement prior to a deropement is detected by a CPS (cable position switch) and are generally only found on detachable lifts. The brittle bar is connected to low voltage electrical circuits (circuits on every tower), and the circuits are all connected to an electrical smart panel that will shut down the ski lift if there are any circuit faults (brittle bars breaks) on any sheave assembly anywhere on the ski lift. The smart panel helps lift mechanics isolate circuit faults to a specific tower and sheave assembly.
All modern ski lifts, of every type (T-bars, chair lifts, gondolas, trams, etc) have brittle bars in place to detect cable derailing. The danger of running a ski lift during a freezing rain event is that ice could built up and freeze the brittle bar in place such that the circuit will not fault, even if the brittle bar does break, so potentially you could have a derailment due to ice, and the lift would not shut down quickly enough to prevent injury to riders. Or the ice could build up and cause a derailment, the brittle bars break properly, and the lift shuts down properly, but now restart cannot happen, and the chair will now need to be evacuated under emergency diesel power. Once you have a deropement, you should not run on electric OR emergency diesel backup UNTIL the deropement has been put back on the sheave assembly. After that you can run in either mode. Derailments are a big pain in the ass for everyone, even if no one gets hurt
*** Comment added Jan 7,2014. Please see member Aug's comment on this topic. My answer as first edited was a little bit wrong, so note that Aug says that modern brittle bars are designed and built to withstand icing. Aug's comments about rope slippage on high speed lifts during icing events was also a learning piece for me.. I stand corrected. - end of Jan 7 ,2014 correction ***
The Mountain Creek Jan 5,2014 freezing rain event: You would have to ask the local operators why they slowed the lifts down, but the most obvious answer would be to lessen the chance of derailment of lift. Some resorts keep the lifts running at low speed during ice events, even if there are no people on the lift, just to lessen the rate of ice buildup that might occur on a stopped lift.
We had a wide spread freezing rain event in Ontario Canada on the morning of Friday Dec 20,2013 that began in the morning and went all day. I was skiing that day. Our low speed lifts were still running (Devil's Glen, Glen Huron Ont - all our chairs are low speed) , however all other ski areas around us (Mount St Louis Moonstone, Blue Mountain,Alpine, Osler Bluffs) closed their high speed chairlifts early that day - mid day. We also closed 30 mins early because the electricity flickered at 3pm and we did not want to evacuate lifts under emergency diesel power. The resulting tree damage from this Dec20 Ontario freezing rain event caused wide spread power outages in Ontario that lasted six days in many places, and longer in some isolated pockets of Toronto Ont. It was a Christmas without power, heat or water for thousands of people in Ontario.
Does that help answer your question?
I hope this helps to clarify
Dino
"Things turn out best for the people that make the best of the way things turn out." A.L.
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Posted 07 January 2014 - 04:08 PM
Lift Dinosaur, on 07 January 2014 - 08:03 AM, said:
Good write up Andy. As a former Patroller and 25 year mechanic I will offer the following corrections below:
I hope this helps to clarify
Dino
I hope this helps to clarify
Dino
Dino thanks for the corrections. I learned something today.
Andy
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Posted 07 January 2014 - 04:26 PM
Glad I could help. Also, CPS is Cable Position Sensor, not switch.
"You ain't an Old Dog as long as you can learn New Tricks"
Dino
"You ain't an Old Dog as long as you can learn New Tricks"
Dino
"Things turn out best for the people that make the best of the way things turn out." A.L.
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