The T3ba’das to Manzinta project was a 34.5kV to 115kV conversion through very difficult terrain. It was broken into three phases over several years due to funding constraints. In addition to design, the scope of work included geotechnical investigation, archeological investigation due to its location on tribal property, and biological investigation since it is in the tide flats of Hood Canal. The footing design in the tide flats was especially challenging, since the soil was very poor up to 80 feet deep; the footing ended up as 40 deep caissons essentially “floating” in the soil.
Worden 115kV Transmission Line
Client Name: Columbia Rural Electric Association
Location: Walla Walla, WA
Contact: Jeff Dietrich
Role: Distribution Engineer
The Worden tap is a double-circuit 115kV transmission line to a new substation. The line is all self-supporting steel poles in poor soils with a full-length static and provisions for two fiber optic cables. The two primary challenges on this project were landowners with changing requests very late in the design process, and the poor soils necessitating a challenging footing design to support the double-circuit transmission.