The American Council of Engineering Companies of Missouri (ACEC/MO) recently recognized Hanson Professional Services Inc. and POWER Engineers Inc. for design work on the CapX2020 transmission expansion initiative during the organization’s annual Engineering Excellence Awards.
The companies received a Grand Award for a transmission line project near Alma, Wisconsin, during ACEC/MO’s awards banquet Feb. 6 in Chesterfield, Missouri. The firms’ offices in the St. Louis area provided design services for Xcel Energy Inc.’s 1.3-mile Mississippi River crossing from near Wabasha, Minnesota, to Alma.
The goal of the CapX2020 program is to provide reliable and affordable electric service to Wisconsin, Minnesota and the surrounding region while expanding access to new power generation, including renewable energy. It involves the design and construction of about 800 miles of 230- and 345-kilovolt transmission lines at a cost of more than $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 150-mile Hampton-Rochester-La Crosse transmission line.
The crossing, which was completed in February 2015 and cost $18 million, presented many challenges. The crossing is within the Upper Mississippi River National Wildlife and Fish Refuge, which is part of a primary bird migration route called the Mississippi Flyway. Vertical limitations for the line’s towers 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; transporting equipment and materials to those sites was done by barges and towboats.
Hanson’s design for the five tower foundations factored in the site’s harsh environment, providing scour protection and supporting the towers against wind, river flooding and ice. 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 new crossing improved the protection of birds along the flyway and has less potential for bird strikes.
ACEC is a professional organization of 51 state and regional councils with members from more than 5,000 engineering firms across the U.S. The annual Engineering Excellence Awards recognizes outstanding achievements from member firms. ACEC/MO Grand Award winners are eligible for the national competition.