Bonneville Power Administration

Bonneville - Hood River No. 1 Rebuild Project

Wilson rebuilt 24 miles of 115kV transmission line along the Columbia River Gorge near Portland, Oregon for the Bonneville Power Administration (BPA). There were a total of 185 lattice or wood pole H-frame structures that were removed and replaced across extremely rugged terrain. Of those structures, 59 were only accessible by trail or helicopter.

Structures at the remote access sites were removed by helicopter and flown to a nearby yard for recycling. Foundations at remote sites were either micropile installations or hand-dug, direct embed steel pole structures. Wilson installed single 556 ACSR Parakeet conductor. The fleet of helicopters that supported this project included the Wilson owned and operated MD 500 and MD 530 as well as a Kaman K-MAX, Sikorsky UH-60A Black Hawk, Boeing 107-II Vertol, Eurocopter AS350B3, and Sikorsky CH-54B which combined for a total of over 1,320 flight hours for the project.

Further work included access road construction, retaining wall installations, rock fall mitigation measures, trail construction, pedestrian bridge installation at remote trail sites, and concrete shaft foundation installations.

Wilson was required to coordinate with multiple agencies that managed sections of the right-of-way along this project, including the Oregon Department of Forestry, Oregon State Parks, Columbia River Gorge National Scenic Area, Friends of the Gorge, Oregon Department of Transportation, and other local and state agencies that had a shared interest in the project.

The extremely rugged terrain presented challenges relating to access and constructability, however, the crews worked extremely well with the helicopter support to complete the work safely and efficiently.