Here?s a thought: use a World War II-era nerve gas can launcher to fight hillside erosion.
That?s what the Minnesota Department of Transportation has employed to repair three roadside shoulders in Winona and Houston counties where dirt washed away in the Aug. 18-19 flood.
On Friday, work crews used the giant gun to shoot 20-foot hollow steel rods into the embankment along Hwy 14 near Saint Mary?s University.
From an excavator, operator Tim Ruckman dangled the two-ton red machine over the guardrail until it pressed against the ground. A series of pressurized chambers released a sharp hiss, then a loud crack as the rods were blasted into the soil at more than 220 mph, sending dirt flying and smoke billowing.
The hollow bars will stay in the ground and act like drains. Some will be topped with plastic mesh and filled with grout for additional protection, said Colby Barrett, vice president of Soil Nail Launcher Inc., which owns the machine.
The device is called a soil nail launcher and there are only four in world, said Kim Ruckman, the company?s senior vice president.
?It?s World War II technology developed to shoot nerve gas cans at the Nazis,? she said.
Britain never used the launchers in war. In 1992, the U.S. Forest Service bought the declassified weapons to build retaining walls. Colorado-based Soil Nail Launcher purchased them in 2001 and they have been used for erosion control in 22 states, New Zealand and Canada.
The DOT signed a $1.5 million contract with Soil Nail Launcher to repair areas of Hwy 14, Hwy 61 near Dresbach and Hwy 76 near Houston. The 28-day project is part of 10 emergency construction contracts in southeastern Minnesota totaling $5.85 million.
A hundred slope-damaged areas have been identified in southeastern Minnesota n a third of the overall damage sites assessed, said MnDOT district engineer Nelrae Succio.
The soil nail launcher, which can shoot 100 nails a day, will save 30 to 50 percent compared with traditional methods because of its quick application and less soil disturbance, said Chris Dulian, MnDOT soils engineer Ruckman said the machine may look and sound intimidating, but its ?controlled chaos.?
?It?s actually pretty boring,? he said. ?It?s like if you get to ride a roller coaster every day.?Winona Daily News
