American Transmission Co.’s (ATC; Waukesha, Wisconsin, U.S.) largest project, the Arrowhead-Weston 345-kV transmission line—spanning 354 km (220 miles) from Wausau, Wisconsin, to Duluth, Minnesota, U.S.—is off to a good start with the first pole set in October 2004. A total of 19 km (12 miles) of 345-kV will be built in Minnesota with the remaining 326 km (203 miles) of the proposed route in Wisconsin. The estimated US$420.3-million interconnect project includes 354 km of 345-kV transmission line and 345-kV line terminal additions at Arrowhead Substation and Gardner Park Substation to accommodate the 345-kV transmission line.

The project scope also includes re-configuration of Weston Substation, expansion of Stone Lake Substation, a phase shifting transformer at Arrowhead and reactive compensation at Stone Lake and Gardner Park substations. Project manager POWER Engineers Inc., a consulting engineering firm with offices in Wisconsin, has been working with project engineers, manufacturers, suppliers and contractors toward a completion date of June 2008.

Construction Materials

To accommodate the enormous inventory of nonengineered supplies, Border States Electric Supply (Fargo, North Dakota, U.S.) was awarded supply chain management responsibilities. Its Waukesha office is in charge of coordinating just-in-time inventory of everything from insulators to grounding cables, as well as packaging, delivery and job-site materials support.

Awarded the contract to supply approximately 1600 steel poles, Thomas & Betts/Meyer shipped its first pole to the Minnesota job site in September. The design calls for weathering steel poles ranging from approximately 36- to 54-m (120- to 180-ft) in height. Several structures weigh in at more than 100,000 lb (45,359 kg) apiece. A total of 50 million lb (23 million kg) of steel is expected to be shipped through 2007. All pole manufacturing is being done at the Thomas & Betts/Meyer plant in Hager City, Wisconsin, located 321 km (200 miles) from the line.

M.J. Electric Inc. (MJE; Iron Mountain, Michigan, U.S.), an InfraSource company, was awarded construction of the 19-km (12-mile) section in Minnesota. The contractor began building foundations and structures on the western end of the line in Marathon and Clark counties in August. On Oct. 8, 2004, MJE, along with ATC, Power Engineering and other stakeholders, celebrated the setting of the first pole.

Slow But Sure

In December, ATC received Chapter 30 permitting and Wetland Water Quality Certification from the Wisconsin Department of Natural Resources. The permits address the crossing of waterways, placement of poles in wetlands, discharge of fill material into wetlands, site-erosion control and storm water management plans. The project will require an estimated 105 temporary bridges and 317 structures in wetlands to minimize displacement in wetland sections of the 354-km route.

Weather has played a key role in minimizing the wetland and swamp challenges during the first phase. Frozen ground minimizes the environmental impact. Approximately one-third of the job will be done working off mats. Alcan Cable (Atlanta, Georgia, U.S.) is supplying the cable for the project.

ATC owns and manages the Upper Midwest grid and is managing construction of the project, which is expected to last until 2010. Upon completion, the line will benefit customers of Minnesota Power, Wisconsin Public Service and other connecting utilities. l