Preempting danger

Tuesday, Mar 3, 2015 12:33 PM Updated Tuesday, Mar. 3, 2015 3:59 PM

A few good artillery shots helps clear U.S. 550 of looming avalanches

A Colorado Department of Transportation worker lines up a shot with a Howitzer that will bring down an avalanche on the Brooklyns chute on the south side of Red Mountain Pass on Tuesday off U.S. Highway 550. CDOT crews reopened the pass after 4 feet of snow fell the past few days, creating an avalanche danger above the highway.

Jerry McBride/Durango Herald

An avalanche comes tumbling down toward U.S. Highway 550 from the Brooklyns chute on the south side of Red Mountain Pass on Tuesday.

Jerry McBride/Durango Herald

A Colorado Department of Transportation worker lines up an artillery shot that will pre-empt avalanche danger on the Brooklyns chute on the south side of Red Mountain Pass on Tuesday.

Jerry McBride/Durango Herald

An avalanche comes tumbling down toward U.S. Highway 550 from the Brooklyns avalanche run on the south side of Red Mountain Pass on Tuesday.

Jerry McBride/Durango Herald

Jerry McBride/Durango Herald Colorado Department of Transportation workers drive through avalanches that have run on U.S. Highway 550 on Red Mountain Pass on Tuesday. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald A Colorado Department of Transportation snow thrower clears U.S. Highway 550 on Red Mountain Pass on Tuesday. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald An explosion during avalanche mitigation work by Colorado Department of Transportation on the Brooklyns area on the southside of Red Mountain Pass on Tuesday on U.S. Highway 550. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald An avalanche comes tumbling down towards U.S. Highway 550 from the Brooklyns area on the southside of Red Mountain Pass on Tuesday during Colorado Department of Transportation’s avalanche mitigation. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald Colorado Department of Transportation workers now use a blast shield when using explosives to mitigate avalanches on U.S. Highway 550 on Red Mountain Pass onTuesday. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald A Colorado Department of Transportation worker, lines up a shot with the departments Howitzer that will bring down an avalanche danger on the Brooklyns an area on the southside of Red Mountain Pass on Tuesday on U.S. Highway 550. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald 03/03/2015- Durango- Colorado Department of Transportation workers drive through avalanches that have run on U.S. Highway 550 on Red Mountain Pass on Tuesday. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald Left over gun powder from Avalanche mitigation work is safely burned by Colorado Department of Transportation on U.S. Highway 550 on Red Mountain Pass on Tuesday. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald Colorado Department of Transportation closed U.S. Highway 550 from just outside of Silverton to Ouray to work on avalanches on Red Mountain Pass on Tuesday. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald The Battleship avalanche chute above U.S. Highway 550 on the southside of Red Mountain Pass on ran naturally overnight and some more after Colorado Department of Transportation’s avalanche mitigation work on Tuesday. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald Colorado Department of Transportation workers now use a blast shield when using explosives to mitigate avalanches on U.S. Highway 550 on Red Mountain Pass on Tuesday. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald A Colorado Department of Transportation shot line up on the Brooklyns area on the southside of Red Mountain Pass on Tuesday on U.S. Highway 550. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

Jerry McBride/Durango Herald An avalanche came down from Eagle overnight covering U.S. Highway 550 on Red Mountain Pass on Tuesday. CDOT crews have been working to reopen the pass after four feet of snow fell over the past few days creating avalanche danger above above the road.

RED MOUNTAIN PASS

With the help of explosives lobbed into about a dozen avalanche chutes, a team from the Colorado Department of Transportation opened U.S. Highway 550 between Ouray and Silverton on Tuesday.

The highway opened at 5 p.m. after 11,018-foot Red Mountain Pass was closed Sunday night by a naturally triggered avalanche.

The goal of shooting avalanches and clearing debris is to reduce the chance of natural slides covering highways, said Nancy Shanks, the CDOT communications manager in Durango. It’s preventative maintenance.

A huge mechanized snowblower was working Tuesday to clear debris from two other natural avalanches that reached the highway on the south slopes of this pass.

Another CDOT crew was clearing 4 feet of snow from the north slope. The team also triggered avalanches, the largest of which was 12 feet deep and 400 feet long at the notorious Blue Point.

The main avalanche-shooting tools Tuesday were a World War II 105mm Howitzer and an Avalauncher, a potato gun-style instrument that uses compressed nitrogen as a propellant.

Each avalanche chute has a name, the origin of which has been lost with time, said Greg Stacy, the CDOT maintenance superintendent based in Durango. Try Cement Fill, Battleship, Eagle, Brooklyns, Mother Cline, Telescope and Mule Shoe.

Permanent concrete launch pads for the Howitzer, the main weapon of attack, are located at strategic points along U.S. Highway 550.

On each pad are two 2-by-2-foot sunken boxes into which the legs of the Howitzer are anchored. They are so oriented to allow the Howitzer to aim at certain slopes.

Susan Hale and Mark Gober, members of the Colorado Avalanche Information Center based in Silverton, monitor storm patterns, recommend closing U.S. Highway 550 when conditions deteriorate and help the Howitzer team direct its projectiles into strategic areas of a snow-ladened slope.

Gober, an eight-year veteran with CAIC, spends summers as a Colorado River guide, a job for which he has more than 25 years experience. Hale, who’s been with the CAIC since the winter of 2004-05, works out of Snowmass as a painting contractor in the summer.

The permanent launch pads have been situated based on years of experience, Gober said. The specific target in a chute also is based on what observers have seen over many winters.

At each launch site, the Howitzer team has a color photograph of the target slope with numbered sites. The coordinates of each target are posted on the Howitzer.

The gunner and his team members manipulate an elevation wheel and a traverse wheel to bring the muzzle of the Howitzer in line with the target.

Military precision is exercised in loading and firing the Howitzer. After the projectile is in place, a series of commands are heard: Clear to proceed, prepare to fire, clear to rear, cover your ears, clear to the front, ready to fire, fire.

Ear plugs are mandatory. A second or two after the Howitzer’s sharp explosion, the discerning eye can see the impact point of the round, identifiable by a powder burn on the snow. A second later, the sound of the impact reaches the firing site.

daler@ durangoherald.com

CDOT team, by rule, goes incognito

RED MOUNTAIN PASS – The Colorado Department of Transportation team that shoots avalanche sites to reduce chances of natural slides covering U.S. Highway 550 work in anonymity.

News media coverage of avalanche shoots can’t report the names of the team members. Their faces can’t appear in photos, either, although photographs that don’t lead to identification are OK.

“Issues of security came after 9/11,” said Nancy Shanks, the CDOT communications manager in Durango. “There have been progressive changes over the years.”

The creation of the Department of Homeland Security brought new attention to security, Shanks said.

Because CDOT avalanche control involves ammunition and guns, the safety of team members could be compromised, she said.

A team member could be coerced to reveal the location of the Howitzer and its ammunition, she said.

daler@durangoherald.com