UPDATE: Faulty gearbox; Rockport skiers jump away from Sugarloaf lift accident
Sugarloaf Mountain is in Carrabassett Valley, in western Maine.
Sugarloaf Mountain is in Carrabassett Valley, in western Maine.
SUGARLOAF — Martha Flint, her daughter, Allie, and husband, Bill, were standing in line around 11:30 a.m., March 21, waiting to ride up Sugarloaf Mountain when when the King Pine chairlift malfunctioned. Chairs suddenly were going backward, striking down skiers in their path. On Monday, March 23, Sugarloaf said investigators traced the cause of the rollback to a faulty gearbox.
“We were standing in line, talking, when all of a sudden we looked up, and people were screaming the ‘chair is ripping backward,’” said Martha Flint, of Rockport. “People below were being knocked like bowling pins.”
March 23 update
According to Sugarloaf, Monday, March 23: “The gearbox failure effectively decoupled the bullwheel from the lift's primary service brake, which is located on the drive shaft between the two gearboxes, and its anti-reverse brake, which is the first of three redundant backup mechanisms for preventing reverse travel.
“Just one day before the incident, the gearbox passed a sophisticated routine preventive maintenance procedure intended to identify potential problems.
“At this point, the emergency bullwheel brake, which uses calipers to apply braking pressure to the flange of the bullwheel itself, was applied by the lift attendant. This brake slowed the speed of the rollback and ultimately brought the lift to a stop. The application of the emergency brake by the lift attendant likely prevented a more extensive rollback.
“The final braking mechanism, known as a drop dog (a large metal pin that drops into the bullwheel to prevent rotation), apparently failed to deploy as designed. Lift mechanics routinely check gearbox oil levels as part of their daily pre-operating checklist. But much like an automobile transmission, the machinery inside of a lift gearbox is not easily observed, so Sugarloaf contracts for routine maintenance tests that can indicate potential problems before they occur.
The tests include oil analysis, which can reveal microscopic particles of metal that indicate undue wear inside the machinery, and vibration analysis, which can reveal gears out of balance and incipient failure.
An oil analysis was conducted on the King Pine lift on January 19, and a vibration analysis was conducted March 20 - one day before the incident. Both tests were conducted by outside contractors who specialize in gearbox analysis, and neither revealed any irregularities.
“The gearbox last underwent major servicing, including the replacement of worn components, just before the start of the 2011-2012 winter season. The work was performed by a contractor who specializes in gearbox maintenance.”
The King Pine lift is on the east side of the mountain, and services black diamond trails. Sugarloaf Mountain is in Carrabassett Valley, in western Maine.
Sugarloaf said in a Saturday, March 21, 1:48 p.m. news release that: “The lift experienced a rollback at roughly 11:30 a.m. resulting in injuries to seven guests. Three guests have been transported to local hospitals by ambulance with injuries that are not believed to be life threatening. No guests were injured during the lift evacuation process.”
On Monday, March 23, Sugarloaf said: “Though it is ongoing, the investigation's preliminary findings revealed that the trigger for the incident was a major mechanical failure in one of two gearboxes connecting the lift's electric motor to its drive bullwheel. A bullwheel is a large, metal wheel, around which the lift cable - which supports the chairs - is tensioned.
All guests were evacuated from the lift by Sugarloaf Ski Patrol and other personnel by 1:22 p.m. A total of 204 people were evacuated from the lift.
During the incident, Martha Flint said the bull wheel, which drives the four-person, nondetachable chairs up the hill, began to move backward, reverting course without stopping. She, Allie and Bill were standing close to the loading point, just two chairs from loading, when havoc ensued. They jumped out of the way, with the approximately 100 other skiers and boarders who were waiting in line.
Those close to loading, however, were knocked down and injured.
“The chairs kept flipping,” said Martha. “Like a tornado that winds around. They were like those chairs at the fair rides, and those ready to load were bowled over by the previous chair. Bodies scattered.”
She said the brake seemed to fail, allowing the chairs to go backward and: “attendees could not seem to stop the carnage. The haulback was littered with skis and boards.”
At towers above, “people were dumping, kicking off their skis and boards, and jumping 15 feet below into two or three feet of snow. The chairs were still going backward.”
In a 20 to 30-second span, six chairs went around the bull wheel, Martha estimated. Two or three men on a few of the chairs went backward around the bull wheel, lifting their skis to avoid collision.
“We got the hell out of the road. Everyone did,” she said.
There were emergency doctors and other medical professionals at the lift, ready to ski, and they jumped to help the injured, said Flint. A ski patroller was further up the hill on one of the chairs, and he jumped off to assist, she said.
Snowmobiles arrived to help bring the injured down the mountain, she said.
According to the afternoon news release from Sugarloaf:
“At this time, all guests have been successfully evacuated from the King Pine lift at Sugarloaf following an incident earlier this morning. Roughly 230 guests were evacuated from the lift by Sugarloaf's Ski Patrol.
A rollback refers to an incident in which the chairlift travels backwards. The rollback did not cause the lift to de-rope. The lift rolled back a distance of nine chairs.
The King Pine Quad is a 4 passenger monocable fixed grip quad built in 1988 and manufactured by Borvig. It is located on the eastern side of the mountain. King Pine is 3,400 feet long with a vertical of 1,074 feet. The chair moves at a speed of 450 feet per minute and the chairs are roughly 51 feet apart. There are a total of 122 chairs on the lift, which is powered by a 400 horsepower motor. It has a transportation capacity of 2,100 skiers per hour.
The chairlift receives routine daily inspections for safety. Additionally, the chairlift receives weekly, monthly and yearly maintenance and testing. The lift is also inspected annually by the State of Board of Elevator and Tramway Safety.
The King Pine lift will remain closed at this time. The cause of the rollback remains under investigation.”
Reach Editorial Director Lynda Clancy at lyndaclancy@penbaypilot.com; 207-706-6657
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