 Poster: A snowHead
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To be fair to the chaps monitoring the lift this problem would not have been easy to see, it's not like a pipe where ice splits it open down the side, a better annalogy would be to think of it like a beer bottle in the freezer, leave it there long enough and as the ice forms it will try to push the lid off, in effect that's what happened the flange was pushed off the top of the tube breaking the weld, initially there would have been a very small deflection perhaps a few mm then it probably let go with an almighty bang and the whole thing would have toppled
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| wbsr wrote: |
..achilles, all lifts have 'mis-alignment' sensors on all towers. When they get triggered, it is normal procedure to slow the lift down. It wasn't 'constantly' out of alignment, so why stop it? We are talking about a haul rope mis-alignment, not the whole tower. Cables 'walk' constantly, and are allowed a certain tolerance. In this case it had hit its tolerance, just , a couple of times over a long period of time.
If the cable was to get too-misaligned, then it stops automatically, no problem, if your aircraft was to 'malfunction' it would crash wouldn't it, big difference.
Since it was at the end of the day, I'm sure they decided to just 'run it slow and download everyone' and then try to figure out the problem overnight.
If they were to stop and evacuate a lift, every time it has a mis-alignment or anti-collision fault, you would be never get to upload. ....... |
Thanks. Of course if an aircraft crashes the consequences are dire - but so can be the consequences of a lift tower collapse. But your points are well made; I now have a much better perspective of the incident, and think the maintenance technicians' decisions were probably reasonable.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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| wbsr wrote: |
| espri, if you were to see where the tower is, It is would be very hard to hit it with a vehicle, even if you tried. |
Another story I've read, is that the concrete was used to stop vibrations and thus to avoid the noise associated with them. Whether that's the true explanation, though, I cannot say.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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Presumeably part of the problem is that Whistler is quite wet isn't it ?
I assume in a much drier environment, such as the Alps, it would be less likely for a pylon to fill with water, though i understand this has happended before in Idaho, which is presumeably very dry ?
Scotland is a wet environment, particularly Fort William where the Nevis Ragne Dopplemayer lift is. However it would be unlikely to get sustained temperatures of minus 25 there.
Another arguement for favouring surface lifts over aerial ones and Gondolas over chairlifts !
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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skierguy_75 & wbsr learned an awful lot from this thread, keep up the good work.
I'd always assumed the towers were hollow open structures.
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You'll need to Register first of course.
You'll need to Register first of course.
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| Peter S wrote: |
| Another arguement for favouring surface lifts over aerial ones and Gondolas over chairlifts ! |
The Excalibur lift in Whistler/Blackcomb is a gondola but I suppose that it better to be in a cabin, if the cable comes off the tower, than in an open chair. That may have helped avoid greater injuries here.
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Just in:
Whistler Blackcomb release regarding full reopening of Excalibur Gondola December 24
EXCALIBUR GONDOLA WILL FULLY RE-OPEN DECEMBER 24
BC Safety Authority and Doppelmayr testing protocol complete
WHISTLER BC, December 23, 2008 - The BC Safety Authority has reinstated the operating permit for the lower line of Blackcomb Mountain's Excalibur Gondola following inspections Tuesday. Repair work on tower 4 was completed Monday and testing took place throughout Tuesday in accordance with BC Safety Authority and Doppelmayr test protocol. The Excalibur Gondola will be in full operation December 24.
"We are extremely pleased with the efficiency in which we have been able to return this lift to operation," says Wayne Wiltse, Whistler Blackcomb's lift maintenance manager. "The tower has been rebuilt, and the cable has been inspected. They have both been non-destructively tested to ensure they meet all code requirements. A thorough inspection, as outlined in Whistler Blackcomb's Safety Management Plan, and following procedures recommended by the lift manufacturer, has been undertaken to ensure the safety of our guests. In addition, the BC Safety Authority has been on-site Tuesday doing its own inspection before reinstating our operating certificate."
In accordance with the lift manufacturer's test protocol, Whistler Blackcomb lift maintenance crews perform a "sounding" test on the towers to check for the presence of water. This test was considered an effective way to check for the presence of water in towers. Following the failure of tower 4, all Doppelmayr lift towers across Whistler Blackcomb were checked for water build-up. This was done first by Whistler Blackcomb lift maintenance crews on Tuesday night after the incident. A secondary inspection was undertaken by Whistler Blackcomb in conjunction with the BC Safety Authority the next morning before operations commenced for the day. Since then, BC Safety Authority has issued a Safety Order requiring all BC ski resorts to inspect all lift towers for water, regardless of manufacturer. In light of the Excalibur incident, Doppelmayr has revised its test protocol to now include concrete filled towers.
The investigation into last week's tower failure remains ongoing. The cause of the tower failure was confirmed by early the next morning, December 17, and was due to an unusual situation called "ice-jacking." Water had accumulated within the tower, then transformed to ice to a point whereby the pressure from the ice created a rupture that separated the two sections of the tower. The force of the ice expansion and the subsequent rupture has been estimated at 800 tonnes of pressure. Prior testing had not revealed this ice build-up due to the tower being concrete-filled.
"Our commitment to safety at Whistler Blackcomb is uncompromised," says Doug Forseth, Whistler Blackcomb's senior vice president of operations. "We have been working around the clock with the authorities and independent experts to understand what happened here last week. Through these efforts, a new Safety Order from the BC Safety Authority, and a safety bulletin from the lift manufacturer has been distributed to ski resort operators in BC and to the industry, in the wake of this incident."
Updated information about Tuesday's incident on the lower line of the Excalibur Gondola will continue to be available for guests and media from the homepage at www.whistlerblackcomb.com. The web site also includes further information about Whistler Blackcomb's operating plan, open lifts, snow conditions, grooming and open terrain.
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Regarding some of the questions posed earlier:
The concrete is in place for stability and strength in the event of vehicle impact, not for acoustical dampening. Although the roadway is a fair distance away from tower 4, a mulit unit residential parking lot is adjacent to the tower. Architectural trees have since grown up around the development, however, 14 years ago the tower was more exposed, hence the concrete. The 3 other towers on the Excalibur that have concrete are located near the roadway & Base II parking lots. Additionally, towers on other lifts on the mountain that have avalanche exposure contain concrete.
I erroneously stated in a previous post that Transport Canada is the independent body examining the lift systems- it is actually the BC Safety Authority (also an independant body).
YAN- you're airbone now- this name was christened after the 1985 Teller lift failure at Keystone. In that case the bullwheel separated from the gear box output shaft- skier's and chairs were catapulted into the air, hence the name. (the bullwheel had been welded directly onto a high carbon steel driveshaft, which is apparently a no-no, and the weld failed) In all, there have been 4 accidents on different Yan lifts, with a total of 6 fatalities.
http://en.wikipedia.org/wiki/Lift_Engineering (note to others reading this thread- Yan lifts have absolutely nothing to do with the Excalibur gondola incident, this was just a side discussion)
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FAQ
