Portland General Electric

Marquam - Harrison 115kV UG Project, OR

Wilson installed eight circuits of 115kV underground transmission line, including a one-mile long circuit, in the waterfront district of Portland, Oregon. Work included pulling seven circuits into a GIS basement with the eighth circuit requiring a 3000’ cable pull across the Tilikum Crossing Bridge. Wilson also supported the cable manufacturer’s splicing and termination crews.   

The project had several unique features, such as the erection of a scaffolded environmental enclosure on a 120-foot tall riser structure and 100 percent video inspection in conjunction with pulling a 30-foot cable slug through the unconventional raceway installed at the Tilikum Crossing Bridge.

Site specific project challenges included congested public thoroughfares, seasonal construction moratoriums, extreme weather, and third-party contractors working adjacent to Wilson’s work zone inside the Marquam substation. Coordination and cooperation with public stakeholders like Portland Bureau of Transportation, TriMet, and the Oregon Museum of Science and Industry were essential to the project’s successful planning and execution.