Flatiron Valley transmission upgrade tests WAPA’s urban craftsmanship

For the final two weeks of August, crews from the Western Area Power Administration’s Rocky Mountain region worked to upgrade a 115-kilovolt transmission line that feeds power to consumers throughout the Loveland, Colorado, area. What made this particular job unique isn’t what was being installed, but where. 

The Flatiron-Valley 115-kilovolt line located south of Loveland’s Highway 34 runs east to west into the foothills of the Rocky Mountains. Like many transmission lines installed in the 1950s, this line was in need of upgrades to ensure the area consistently receives reliable power. And while the replacement of its 25 “H-frame” structures isn’t a new task for WAPA crews, the challenge of performing the task in an urban environment adds complexities.  

When the Flatiron-Valley line was first constructed, much of the land was still used to farm sugar beets and sour cherries, cash crops routinely found throughout Big Thompson River communities. Over the years, with the growth of nearby Denver, farming communities gave way to suburban corridors, complete with shopping centers, department stores and new roadways. This evolution in the community also means a sightly more challenging environment for power grid maintenance and upkeep. 

“This job’s a little bit different because we’re going right through the neighborhoods of Loveland,” said Ron Miller, one of two line foremen assigned to the project. “Most of our lines are just out randomly in pastures. The line was built somewhere in the early [1950s], and the community has built all around them, and that still continues today.” 

The nearly $400,000 worth of upgrades not only replaced existing pole structures but incorporate reinforcements to ensure the line is secured for decades to come. The project also raises the height of the lines to provide for greater clearance. One of the drawbacks of the previous power transmission structure design was a tendency for power lines to “gallop” as the result of heavy ice and wind. As the lines gallop with either bucking or bouncing movements, they can touch, resulting in temporary power interruptions, or more severe situations including the collapse of transmission poles or power lines falling down. 

To ensure the upgrade was completed on time, crews coordinated with local residents as WAPA bucket trucks and equipment were placed in rights of way. Traffic control was also needed, ensuring shoppers and drivers maneuvered around the machinery. This, coupled with precision removal of old poles and their replacement, meant very little margin of error. 

One of the crew’s newest members, Slater Durbin, a lineman apprentice based in RM’s Craig, Colorado, office, said keeping the power on makes for a good feeling. 

“I’ve been doing structures going on close to two years now,” Slater said. “I like all the transmission work. I like climbing the tall poles, the tall structures. I like hanging out of the helicopter. All the fun stuff I like.

“This is a very good crew … I haven’t met a wrong one yet and I love it,” Slater continued. “Getting into the line trade — you do a little bit of grunt work, but everybody helps out. Everybody works together.”

Customers benefitting from the line’s upgrade include Platte River Power Authority, Poudre Valley Rural Electric Association, Tri-State Generation and Transmission Association, and the Cities of Estes Park and Loveland.