An extensive and thoughtful restoration effort has remedied the Third Avenue Bridge’s deteriorated condition and extended its service life. The downtown Minneapolis bridge was originally designed and built in the early 1900s and will soon be placed on the National Register of Historic Places for its historic and engineering significance.

Scope of work included repairing, strengthening and implementing a robust corrosion protection plan on the Melan steel truss arches, which had significant section loss. River piers had large portions of delaminated and spalled concrete that were restored. Crews also replaced concrete spandrels and deck and refurbished historic ornamental railings.

Foundation repairs required extensive and prolonged dewatering. Construction access to the bridge on the water was severely limited because of the bridge’s proximity to a hydroelectric generating station, a historic horseshoe dam and a permanently closed lock. Three of the seven spans were inaccessible by water, while the remaining four were accessible by only small barges. To remove and replace the structural concrete and perform surface repairs, the team took a top-down approach with the help of an elaborate multilevel hanging scaffold system below the bridge. Large sandbags diverted river flow to allow rehabilitation of two piers, and for another four, the team used cofferdams. Although tower cranes limited loading on the bridge, they allowed for a downstream access lane and phased construction.