Hello folks! I wanted to put out a statement concerning the incident on North Chair this past Saturday that caused a deropement on tower 6. First and foremost, nobody was injured or even put in harms way during the incident. Only one lift operations employee had to be evacuated by ski patrol and that process went perfectly. A huge thank you to our patrollers for getting him down safely! We’ve been seeing and hearing a lot of speculation and doomsday rumors about what happened, so here’s a complete rundown to clarify everything that happened and why it happened.
During the August 7th tornado, trees fell on the haul rope of North Chair and shifted the concrete foundations of towers 5 and 6. We had an engineer examine the damage, and come up with a solution to realign the towers and recreate the soil conditions around the foundation as efficiently as possible. This process was done by excavating around the tower bases, slowly moving the foundation back into its original position, and re-compacting the soil as we filled in around the cement. We then had the towers surveyed to find that they were only 1.5″ and .75″ out of alignment with the center of the top and bottom bull wheels, a result well within the tolerance of the sheave adjustments. At this point, we were able to make the necessary repairs on top of the tower and achieve perfect alignment of the haul cable across the sheave wheels. The rest of the annual maintenance and testing was completed and the chair passed its inspection by the Department of Labor and full dynamic load test on the 16th of February. The lift was open to the public and ran beautifully for 4 days during president’s week.
On Saturday, February 24th, the lift operations crew started North Chair around 9am. They went through the normal opening process of testing safety circuits, backup auxiliary motor, lowering seats, etc. The top lift attendant road the lift to the top of the mountain without incident, and all seemed fine. While finishing their opening procedures, the lift stopped on its own and the safety circuit was lost. This is not an uncommon occurrence, there are several safety switches on a lift that can be accidentally tripped by a swinging chair, ice in the switch, even a bird perching on top of it. The crew checked all of the switches at the bottom of the hill, and found no issues. It was then assumed that the problem was uphill and the most likely culprit was a simple tripped switch. Under my direction, one of my lift supervisors switched the lift to bypass the safety circuit and ride it to the top to check all of the switches along the way and on top of the lift. A deropement was certainly not in anyone’s initial thoughts, as they are rare and the lift had been running perfectly since it was opened following its successful load test. After passing tower 4, my lift supervisor saw the deropement on the downhill side of tower 6 and radioed down to immediately shut off the lift, which it was. He was then successfully lowered to the ground by ski patrol and our investigation into the cause of the issue began. Upon arriving on the scene, I realized that the lift’s safety circuit worked exactly as designed, and the only reason for the chair pileup on tower 6 was my direction to run the lift on bypass to investigate the cause.
It only took seconds for me to spot the issue, which was another shift in the cement foundation. A one inch gap between the cement and the frozen ground showed that it had twisted in the ground, with the only explanation being a frost heave undoubtedly caused by rain and temperatures in the mid-40’s the two days prior, and temperatures abruptly dropping below zero the night before. I had inspected the sheaves of that tower very closely a number of times following the load test and prior to the 24th. There were no indications of any issues with the sheave alignment or their operation up to that point. Leaving a frost heave of the foundation to be the only reasonable explanation.
That following Monday, I walked through the entire incident with our Department of Labor inspector who oversees the inspection of our lifts. He agreed that this had to be the cause and I provided any and all documentation needed for them to complete their investigation. We now work to remove the affected chairs from the haul rope and will go back to the drawing board with our engineers and all other necessary parties to come up with a solution to get North Chair back in operation next season.
Again, I am incredibly thankful that no one was injured and the pictures that have been circulating make it look much worse than it was. We look forward to conquering this issues once and for all during the off-season and appreciate all the support and words of encouragement that we’ve received thus far.
Now, let’s all do yet another snow dance and cross our fingers for a colder, snowier March than the forecast is showing! See you out on the slopes!
Nick Mir
General Manager