Alaska's engineers build ice bridges
January 31, 2012
FORT WAINWRIGHT, Alaska (Jan. 31, 2012) -- The setting couldn't be more bleak: averaging negative 20 degrees before the wind chill is factored in, the frozen and lifeless landscape spans in almost all directions.
Sheets of ice creak and groan while a team of specially trained Soldiers dressed in subzero-rated arctic coveralls move across the surface of the once flowing and animated Tanana River.
The river still runs under its thick cover of ice, making the movement across the surface even more dangerous for heavy military vehicles and equipment.
Since mid-January, members of the 2nd Engineer Brigade stationed at Joint Base Elmendorf-Richardson have been braving the cold and dark to construct ice bridges to safely move Soldiers, weapons and equipment across the expanses of both the Tanana River and the Big Delta River near Delta Junction and Fort Greely.
The projects are helping the Soldiers of the 56th Engineer Company hone their arctic construction techniques and provide safety routes for Air Force units to move large containers and personnel to training areas.
The engineers first clear the surface of loose snow and use it to form berms on the left and right limits of the bridge site, checking the ice depth as they move across the river.
They drill through the ice to locate a water source to pump and spray onto the surface of the frozen river to thicken the ice layer to a safe depth and strength.
When water isn't available on site, it must be trucked in from another location.
The bridge is declared safe for use is when it is four feet thick and graded flat, according to Pvt. Jacob Zipter, a masonry specialist engineer with the 56th Engineer Company working on the bridge near Delta Junction on Fort Greely.
"Our bridge site is too shallow to drill down to a water source, but it still needs to be thicker for heavy trucks to cross in case there are any air pockets in there," Zipter said. "We've had to haul in water from somewhere else in order to spread it across the surface before it freezes to make it thicker and fill in any cracks toward the middle."
At the Tanana River site, closer to Fort Wainwright, a second team constructs a similar bridge but is able to pump water from beneath the frozen surface.
The teams at both sites include engineers, medics and leadership experienced in arctic winter safety. Many of the senior members are graduates of the Cold Weather Leaders Course taught at the Northern Warfare Training Center, the Army's premiere location for training on arctic and mountain operations.
"Our purpose with these bridges is to better prepare our guys to do these sort of things and in this sort of environment but what we don't need are any unnecessary cold-weather casualties while we're out here. Our medics do regular checks to make sure no one loses any fingers to frostbite," 1st Lt. Ann Prakfield, a platoon leader with the 56th Engineer Company, said. "We could potentially find ourselves conducting similar joint missions with foreign armies and our experience would become invaluable in that situation."
Each bridge construction area is also equipped with on-site warming facilities for both the personnel and sensitive equipment that needs to be regularly thawed out.
Supply vehicles, especially the tracked Small Unit Supply Vehicles, or SUSVs, regularly move people and supplies back and forth from the local bases of operation to the construction areas.
Construction of the bridges is expected to continue until late February and will be useable until the thaw later in the year.