CARRABASSETT VALLEY – Investigators into the chairlift malfunction at Sugarloaf on Saturday said preliminary findings indicate the lift’s brake systems failed to deploy, which caused the four-person chairs to slide backwards. Some riding the lift jumped off as the chairs slid backwards down the slope. Using a hand emergency brake, a lift attendant was able to stop the lift, the resort’s spokesman said on Sunday.
Seven skiers were injured after the King Pine quad chairlift slid backwards in what is referred to as a rollback. Three people were transported by ambulance to Franklin Memorial Hospital in Farmington. A hospital spokeswoman there said two adults were released after treatment and a third adult was transferred to Central Maine Medical Center in Lewiston for further treatment. Sugarloaf described the injuries as non-life threatening.
In a two-hour rescue operation by ski patrollers and firefighters, 204 chairlift riders were evacuated.
One day after a rollback incident, investigators, including an engineer from the state’s Board of Elevators and Tramways, “found 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,” said Sugarloaf spokesman Ethan Austin in an email. A bullwheel is a large, metal wheel, around which the lift cable, which supports the chairs, is tensioned.
“The gearbox failure de-coupled 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,” he explained.
“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.
“The cause of the gearbox failure and the failure of the drop dog to deploy as designed both remain under investigation,” Austin said. “It is likely that determining the root cause of these failures will require extensive analysis.”
Gearbox oil levels are routinely checked each day of operation, the resort said, and Sugarloaf contracts for regular maintenance tests.
“An oil analysis was conducted on the King Pine lift on Jan. 19, and a vibration analysis was conducted one day before the incident. Both tests were conducted by outside contractors who specialize in gearbox analysis, and neither revealed any irregularities,” Austin said.
The lift will remain closed pending further investigation.
Sorry for those who were hurt and wish them full and speedy recoveries. For any sue happy individuals looking to blame someone, equipment, by nature, is not infallible under the best of care and preventative maintenance schedules. YOU put yourself at risk every time you get behind the wheel of a car, or step on an elevator, or board a plane, etc. Kudos to the lift operator for having the wherewithal to apply the hand brake under such chaotic circumstances and undoubtedly preventing many more injuries.