New Westminster (BC), Canada – Following the collapse of Blackcomb Ski Area’s Excalibur Gondola in December 2008, the B.C. Safety Authority (BCSA), which oversees ski lift safety within the province, has enacted new regulations designed to prevent a repeat of the accident.nBCSA investigators found that the Blackcomb mishap, which injured 12, occurred due to “ice jacking,” a phenomenon by which water within the lift tower freezes and expands, separating tower joints. Six of the lift’s 33 cabins were damaged when the upper section of one of the ski lift’s towers collapsed.
According to Jason Gill, the Safety Authority’s safety manager for passenger ropeways, water entered the tower’s cavity, probably through a plate connecting the tower’s upper and lower sections, and then froze after it was unable to drain out. A rectangular opening on the plate — used to pour concrete into the lower section during the tower’s installation — and a flame-cut bolt hole are both believed to have provided a pathway for water to enter the tower.
Unusually cold temperatures in the Whistler area before the incident froze the water that had collected in the lower section of the tower. The ice then expanded inside the cavity, pushing against the walls and the plate, eventually causing the tower to collapse.
The Excalibur Gondola had been in service for 14 years at the time of the tower collapse and had no serious incidents reported, said Gill.
As a result of the investigation, six recommendations have been made to help prevent a similar incident from happening again. All ski lift towers in the province must be fitted with drain holes or other means to prevent the accumulation of water, as required by the national standard. Manufacturers must make sure that required inspection procedures are clearly communicated. Contractors must make sure that manufacturers’ safety bulletins are followed by staff, and that inspection and test results are properly documented. Manufacturers must make sure that “as built conditions” are documented and transferred to the owner and operator during installation. The BCSA will submit its findings to the national CAN/CSA Z98 Technical Committee for review and possible code changes. And finally, the BCSA will improve processes to make sure its safety officers are aware of and document manufacturers’ safety bulletins.
Gill has also issued this week a Safety Order to ensure compliance with the first recommendation noted above. As a result, all ski lift towers in British Columbia must be outfitted with drain holes by this coming November.