A new remote avalanche control system will be operational this winter at Three Valley Gap, reducing highway closure times and improving public safety.
The Ministry of Transportation and Infrastructure announced in June 2015 it would be installing a new automated system and, in Aug. 2016, that Swiss company Wyssen Avalanche Control, Inc. had been awarded a $2.1 million contract to provide it.
Robb Andersen, MOTI senior manager, avalanche and weather programs/construction and maintenance branch, expects the system will be operational by mid-November, and says there is excitement among his peers to see it in action.
“It’s been a big project,” said Andersen. “This type of device, this is the first one that’s been installed in North America… So we’re very excited to employ this new technology within our avalanche program, and it’s a good device for that location for what we need.”
Andersen provided the Review with a detailed explanation of the project and how system works.
First off, he said the project involves the installation of eight permanent towers, between eight and 12 metres tall, placed in specific avalanche paths up high on Three Valley Gap’s steep terrain over the Trans-Canada Highway. These towers are to accommodate the explosives that will be used to trigger avalanches.
Only four of the eight towers will be operational this winter, with the remaining four being installed next spring.
“So the ones that were installed this year were the ones that we felt were going to be the most effective, the most frequent avalanche areas that produce the largest avalanches, so they were prioritized,” said Andersen, adding the public won’t see the full benefit of the system until next winter, but it will still have a positive impact. “It will give the avalanche control team a chance to figure out operationally how to best use it and how effective it is and we’ll go from there.
With the towers in place, a round, detachable/refillable deployment box is placed on top by helicopter. These circular boxes each contain 12 explosive charges, four-and-a-half kilograms in size.
“From the highway, the avalanche technician, through a secure, remote radio communication… can sit at a computer in their truck and communicate with these towers and be able to remotely deploy one of these charges,” said Andersen.
Andersen said the towers are on a 15-degree-angle, hanging over the avalanche path. When a charge is deployed, it drops from the box on a 10-metre rope. When it reaches the rope’s full length, a fuse inside is ignited, leaving a 45-second delay before detonation.
Andersen said the charge detonates while suspended above the snow’s surface, providing a much better effect than if it were in the snow. This, he said, is just one of the benefits over the normally used practice of helibombing. Another is that explosives from each of the towers can be triggered at once. Andersen said this will result in a significant time reduction to the ministry’s highway avalanche control efforts, from about an hour to maybe 15 minutes.
“It’s probably an hour, maybe an hour and a little bit of avalanche control, and maybe 45 minutes to an hour of clean-up,” said Andersen. “Being able to do the avalanche control in 15 minutes now, we should be able to reduce the highway closures from an average of two hours, to an average of one hour or maybe even less, depending on the size of the avalanches.”
Another benefit of the new system is that, unlike helibombing, it’s use is not restricted by weather conditions – avalanche control would be possible 24/7. This means the ministry could do it more frequently, resulting in smaller avalanches and, subsequently, less highway clean-up.
“That will also get the highway open that much sooner,” said Andersen.
Asked about the impact that closures of Highway 1 have on the province’s economy, Andersen said it’s been estimated to be a loss of about $500,000 an hour.
“The BC Trucking Association was suggesting with the recent rockslide that closed the highway in Field, they were losing about $75,000 an hour – just the trucking industry…,” said Andersen. “I think there’s a little over $9 billion a year in trade that goes up and down the highway, so if you calculate that it ends up being about half a million.”
And then there’s the safety angle, and that doesn’t just pertain to those travelling Highway 1. Andersen said helicopter bombing is inherently risky, and the new system will reduce the risk for avalanche crews and maintenance contractors who work in the avalanche area.
Andersen noted Parks Canada has also invested in avalanche safety measures for Rogers Pass. Speaking specifically to the Wyssen towers, however, hey said they will go a long way to help achieve the ministry’s goals for reducing road closures and providing an acceptable level of safety.
“That’s really why we’re doing this,” said Andersen.
The attached video from Wyssen shows how the towers will work.