The last section of a rebuilt electric transmission line between Conover, Wis., and Quinnesec, Mich. has been placed into service. “Upgrading this 74-mi line from 69 kV to 138 kV has helped reinforce the electric system in the entire region,” said Tom Schemm, construction project manager for American Transmission Co., owner and operator of the line. “These were some of the oldest facilities on our system, and the need for system improvements in this area was evident in the 1990s.”

ATC proposed the project in 2004; it was approved by the Public Service Commission of Wisconsin in 2006 at an authorized cost of $118 million. The project also included a new 16-mi,115-kV line between Eagle River and Conover, which was placed in service in June 2008. Rebuilding the lines between Conover and Quinnesec began in 2009 and was completed more than two months ahead of schedule and about 12 percent under budget. The project also involved construction of two new substations and modifications or upgrades to six additional substations.

“These facilities essentially complete the interconnection of three previously weak areas – the 115-kV system north of Wausau, the western Upper Peninsula and the Iron Mountain, MI., area,” Schemm said. “That will increase overall reliability in the area and improve our ability to transfer power between northern Wisconsin and Upper Michigan.” The older facilities also were vulnerable to lightning strikes and outages.

“Collaboration with our contractors, vendors and suppliers, including MJ Electric Inc. and Black & Veatch Engineering, helped us squeeze some of the cost out of the project through strategic use of lay-down yards, redesign of poles and foundations and efficient use of labor,” Schemm said. “Lessons learned on this project will be incorporated in our future construction activities.”