DOT artillery defends Thane Road from avalanche threats

Melissa Griffiths of Douglas walks her dog, Beau, on Sandy Beach, where she has a great view of the Thane avalanche chute across Gastineau Channel.

“I know that the state blasts a howitzer, and I was wondering, who does that and are there specialized skills that you need?” Griffiths asked.

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Alaska’s Department of Transportation operates the howitzer to protect Thane, a community of about 60 houses 5 miles south of downtown Juneau.

“The only way to Thane is on Thane Road and we have to drive through some avalanche chutes to get here — and so that’s just a given,” said Larri Irene Spengler, who is active on the board of the Thane Neighborhood Association.

That’s right: one way in and if an avalanche strikes, no way out.

Her husband, Steve Behnke, recalled a February 2009 avalanche that left him stranded in Juneau while his family was home in Thane.

“It makes you real aware of that mountain, ya’ know?” Behnke said. “It just makes it real because so much of the time we just drive back and forth and don’t pay full attention.”

DOT’s solution is gunning down the avalanches before they build up large enough to threaten the road.

On a recent afternoon, a crew is waiting for Juneau’s air traffic control tower to clear the airspace

“Are we gonna shoot?”

“They’re clearing the air … so I guess they’re gonna start now.”

“The last time we got one on our first shot and everyone got all excited and it brought a lot of snow down — after that nothing happened,” said Scott Gray, DOT’s operations superintendent for the Southeast District.

They fire the first shots. Within minutes, the snowpack begins to give way.

“There’s a nice little dump of snow there,” Gray said. “That was a nice one.”

More shots are fired.

Every two minutes the howitzer roars as an artillery shell is lobbed 3 miles across Gastineau Channel.

More snow cascades down. It’s effect is mesmerizing — almost hypnotic.

“It’s kind of interesting to watch,” Gray said. “The powder leaves the air — it’s like a waterfall just coming down — it’s pretty.”

The howitzer has triggered a slide to prevent a a larger, uncontrolled avalanche that could swallow up Thane Road.

A few days later DOT offers a closer look at the howitzer.

Casey Walker is DOT’s maintenance foreman in Juneau. He explains that the howitzer belongs to the U.S. Department of Defense.

“It’s pretty much like a big rifle,” he said. “This is your breach block. The bullet goes in and you close the breach behind it and then your triggering mechanism is just your typical rope pull.”

Military regulations only allow a handful of authorized people near the gun when it’s assembled and loaded.

“It’s a military weapon and we use it for avalanche mitigation strictly, and so they want to make sure that it doesn’t fall into the wrong hands, number one,” Walker said. “And number two, it is operated and maintained the way that the military expects it to be.”

A master gunner is always part of the DOT firing crew. It takes 10 years to reach that certification.

The rest of the crew are checking each other’s work to make sure the howitzer is sighted accurately to one of 24 pre-selected target points.

“We have a guy on each side of the gun. We plug in the coordinates. We have a guy that loads, he loads the gun and then he double checks everything,” Walker said. “And then the guy on the left-side of the gun triple checks everything and then we do our all-clear and make sure everything’s good to go and fire a round.”

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