Skiers and snowboarders were stranded on Mount Sima's new chairlift for 40 minutes last Friday afternoon after a safety switch tripped just before closing time.

Parker Hickey, the hill's general manager, said today he's almost certain the switch was tripped by a chair that was sent swinging into the bullwheel when a couple of teenagers jumped off after riding past the normal off-loading ramp.

It took some time to correctly bypass the fault.

With assistance over the phone from representatives of the company that supplied the lift staff at Mount Sima, staff were able to engage the auxiliary diesel motor, said Hickey.

He said he's confident now that if a similar situation occurred, they'd have the auxiliary up and running in five minutes or fewer.

Staff had been trained in starting and operating the back-up motor before Mount Sima opened Dec. 15.

Last Friday's incident was complicated by the fact they were having to find their away around an unknown fault on a new system, Hickey said.

"I am very confident in saying if it happens again, the guys would be able to do it in five minutes,” Hickey told the Star.

The chairlift, after all, could stop at any time for the simplest of reasons, like a power outage, Hickey said.

There were about 100 to 135 people on the chairlift when it shut down, he estimates, adding the maximum number of seats going up is 200.

Hickey said the computer logged the fault at 2:57 p.m., just three minutes before closing time.

It appears, he said, the safety switch tripped at the exact time the chair was sent swinging into the bullwheel, at the precise time staff recalled hearing the chair hit the back of the steel structure.

While he's reluctant to assign blame, a couple of eyewitnesses did see a couple of youth on the ground laughing at the time the chairlift came to a stop, said the general manager.

"It would be nice to kind of get the message out that jumping off the chair is a really bad idea at any time.”

Hickey said staff were on the phone with engineers from Doppelmayr for about three hours last Friday before they were finally able to isolate the safety switch that tripped off.

The switch, he said, was sort of turning off and on, just like when you bring your car into the garage with a problem but the mechanic can't find anything because all of a sudden the vehicle is working fine.

Ongoing problems with the old chairlift in the last couple of years were the source of growing concern for not only skiers and boarders, but also for the board of directors of the Great Northern Ski Society.

Last spring, while announcing a $1.6-million contribution from the City of Whitehorse toward the purchase of the new $3-million lift, ski society president Craig Hougen said the board had considered closing down the hill because of the unreliability of the old chairlift.

It was, he said, an issue of safety.

One incident last December saw some people stranded on the lift in relatively mild and calm conditions for almost three hours until it was their turn to be removed by emergency evacuation personnel.

Hickey said Sima staff are trained in evacuation procedures but he was entirely confident on Friday afternoon they would be able to get the auxiliary motor up and running, and that there'd be no need to implement an evacuation.

Attendance at Mount Sima since it opened has been solid and the conditions at the hill are "very good to excellent, with an emphasis on excellent,” he said.

The new chairlift is what the ski society is calling its anchor to a new, all-season Mount Sima facility that will provide mountain bikers and others with a lift to the top in spring and summer season.

The chairlift is also designed to provide passengers with a ride from the top to the bottom.

Mount Sima has also built a one-kilometre ZOOM zipline that starts at the top and a Monkido Aerial Adventure Course near the bottom of the hill.