PROJECT
Nestled in Phelps Mill Park lies the only remaining steel truss bridge in Otter Tail County, MN. Phelps Mill Bridge was constructed in 1907 as part of the Main Township road system and designed to better serve Phelps Mill, a flour mill constructed in the late 1800s. The bridge spans 123 feet and was used for vehicular traffic connecting Phelps Mill Road to County State Aid Highway 45, as well as pedestrian traffic.
The bridge was initially utilized to support both vehicular and pedestrian traffic to the mill and surrounding areas, including Phelps Mill which was listed on the National Register of Historic Places in 1975. In 1984 the Phelps Mill Historic District was established which only enhanced the bridge’s significance and the importance of preserving the structure. In 2001, Maine Township requested Otter Tail County take over ownership as the bridge began to show increasing signs of safety concerns involving the truss system and bridge pier. Otter Tail County considered the bridge’s condition, location, and traffic, along with the importance of the structure and decided to move forward with a project to restore the structure for pedestrian use.
SOLUTION
KLJ’s bridge experts worked closely with MnDOT and Otter Tail County to develop an innovative project to restore the bridge while still maintaining the historic integrity. To correct the deficiencies, the timber deck was removed and replaced with new timber. The pins, lower chord truss members and lower chord bracing members were replaced with new steel members detailed to physically resemble the original members as closely as possible. The deteriorated steel stringers were replaced with new steel beams similar to the original members. The center pier, which had displaced vertically and laterally, was replaced in-kind to retain the appearance of the original bridge. KLJ also provided project memorandum, public input coordination, environmental coordination, and construction administration.
RESULTS
Today, the bridge is open and provides pedestrians a safe connection across the Otter Tail River in Phelps Mill Park and provides a spectacular view of the scenic Phelps Mill building and park. In 2014, the Phelps Mill Bridge received an Honorary Minnesota American Council of Engineering Companies (ACEC/MN) award which was rated on uniqueness and/or innovative applications, future value to the engineering profession and perception by the public, social, economic, and sustainable development considerations, complexity, and successful fulfillment of client/owner's needs.
