Remote controlled slides near Lizard Head Pass
A remote-controlled avalanche system will be installed over Colorado Highway 145 near Lizard Head Pass that will lower a load over the slide.
With the kind permission of Wyssen Avalanche Control
Avalanche control work on Colorado Highway 145 will be carried out remotely starting this winter.
Colorado Department of Transportation
Avalanche control at Lizard Head Pass on
Every winter north of Rico the avalanche trails Yellow Springs Wall, Yellow Springs Gully and Peterson fill with snow and threaten to spill Colorado Highway 145.
“When we have heavy snow, these slides can often cause snow to hit the highway,” said Brian Gorsage, coordinator of the CDOT avalanche program.
His crews handle and fire explosives from long-range guns to trigger avalanches on closed highways, then the crews plow the snow. They use “avalaunchers” to fire projectiles at the snow slide area or a howitzer cannon that shoots ammunition into the slide areas of the Lizard Head Pass when needed.
But to improve efficiency and protect workers, the blast will be detonated remotely from five 30-foot towers near the slides this winter.
Wyssen Avalanche Control, based in Switzerland, installs the devices on mountain slopes and ridge lines in August and September.
When triggered by the remote control, a pressurized gas container attached to a tether is lowered to a preset height above the glide slope and then ignited.
“The shocking explosion triggers the controlled avalanche. We don’t want them to slide naturally because of the threat to the traveling public, ”said CDOT spokeswoman Lisa Schwantes.
CDOT’s Avalanche Mitigation Program will operate the system. Gorsage said CDOT worked with the San Juan National Forest over the past year to obtain permits for the installation.
Remote systems have been shown to be more reliable and secure for avalanche control personnel, CDOT said. They also enable faster and more efficient avalanche prevention and make traveling in the area safer for motorists.
“Colorado 145 and Lizard Head Pass are the alternative route for travelers heading north when the US 550 Mountain Corridor is closed to emergencies,” said Jamie Yount, manager of CDOT winter operations programs. “This new avalanche defense system will help us keep CO 145 open more easily and provide drivers with a higher and more reliable level of service, especially when avalanche conditions and cycles occur in the San Juan Mountains during major winter storms.”
To trigger an avalanche, a coded command is sent by remote control to the deployment box on top of the tower. The insert box contains 12 explosive charges.
When the explosive charge is dropped, two detonators are drawn and the explosion is triggered with a time delay. The cargo gets stuck on a string that falls off completely after being blown up. To reload explosive charges, the entire deployment box is lifted from the tower by helicopter and brought into a station building.
The remote controls will be installed in Colorado 145 over six to eight weeks beginning August 4th. In general, drivers should expect minimal traffic disruption, as most of the work takes place away from the motorway.
Regular working hours are Monday to Friday from 8 a.m. to 4 p.m. Weekend work is not provided. Traffic in the work area is limited to 40 km / h.
CDOT operates more than 30 remote systems in multiple locations on high mountain highways and the Interstate Highway 70 corridor.
Each winter, CDOT and its sister agency, the Colorado Avalanche Information Center, monitor and control approximately 278 of 522 known avalanche paths on Colorado Highways.