February 2016
HAILEY, Idaho (Feb. 8, 2016) — POWER Engineers Inc. and Hanson Professional Services Inc. share a 2016 Engineering Excellence Award from the American Council of Engineering Companies of Missouri for their design services that helped Xcel Energy Inc. complete a critical Mississippi River transmission line crossing as part of the CapX2020 transmission expansion initiative.
The five CapX2020 transmission projects provide reliable and affordable electric service to Wisconsin, Minnesota and the surrounding region while expanding access to new power generation, including renewable energy. CapX2020 involves the design and construction of about 800 miles of 230- and 345 kV transmission lines at a cost of an estimated $2 billion. Eleven utilities, including Xcel Energy, are partners in CapX2020, which is the largest development of new transmission capacity in the region in more than 40 years. Xcel Energy is the managing partner for the 156-mile Hampton-Rochester-La Crosse transmission line.
The 1.3-mile river crossing of the CapX2020 Hampton-Rochester-La Crosse project was completed under budget at $18 million in February 2015. The crossing links an 85-mile, 345 kV transmission circuit between eastern Minnesota and western Wisconsin. The river crossing runs from near Wabasha, Minnesota, to Alma, Wisconsin.
“We’re extremely proud of the success of this project and of our teams who put so much work into making it a reality,” said Aaron Boston, POWER’s project manager for CapX2020. “This award validates our trusted partnership with Xcel Energy and our teamwork approach.”
ACEC Missouri presented a Grand Award to the two firms at its winter meeting and awards banquet Feb. 6 in Chesterfield, Missouri. POWER and Hanson both have regional offices in St. Louis.
POWER served in a number of roles for CapX2020, including providing overall owner’s engineer support. POWER’s team helped develop the overhead line design to meet CapX2020 requirements and environmental and navigation requirements from the U.S. Fish and Wildlife Service and U.S. Army Corps of Engineers.
The river crossing project presented major challenges. Strict vertical limits required that the conductors be at least 90 feet above water and the towers be below 200 feet in height. To minimize span lengths, one tower was placed on an island and another on a peninsula. Hanson’s design for the five tower foundations factored in the site’s harsh environment, supporting the towers against wind, ice flows, river scouring and flooding.
The tower sites on the island and peninsula could be reached only by barges and towboats. Helicopters pulled ropes across the river to string transmission lines and dropped off linemen on top of the towers.
During construction, heavy rain resulted in unusually high water levels, which brought multiple delays and a brief closure of the shipping channel because sand washed into it. An early freeze left construction crews on a tight deadline with no choice but to work around ice chunks in temperatures that fell below zero.
The crossing’s location within the Upper Mississippi River National Wildlife and Fish Refuge, which is part of a primary bird migration route called the Mississippi Flyway, presented other challenges. The area is home to more than 270 active eagles’ nests, which complicated construction when the bald eagle nesting season began. To avoid affecting one nest, crews maintained a 660-foot buffer and stopped using the helicopter.
The Missouri organization’s Grand Award qualifies the entry for the national ACEC competition. ACEC will announce national winners April 19 in Washington, D.C.
About POWER Engineers
POWER Engineers is a global consulting engineering firm specializing in the delivery of integrated solutions for energy, food and beverage, facilities, communications, environmental, and federal markets. POWER Engineers offers complete multidiscipline engineering, architectural, and program management services. Founded in 1976, it is an employee-owned company with more than 2,100 employees and over 45 offices throughout the United States and abroad. For more information, please visit www.powereng.com.
About Hanson Professional Services
Hanson is a national, employee-owned consulting firm providing engineering, planning and allied services. The firm’s corporate headquarters is located at 1525 S. Sixth St., Springfield, IL 62703. The office may be reached at (217) 788-2450. For more information, please visit www.hanson-inc.com.