Stillwater Lift Bridge (Bridge 4654)
History & significance
The Stillwater Lift Bridge carries State Highway 36 over the St. Croix River between Stillwater, Washington County, Minnesota, and Houlton, Wisconsin. Constructed in 1931, the 10-span bridge includes six steel Parker through truss spans, one movable span of the type commonly known as a “Waddell and Harrington vertical lift,” and three concrete slab approach spans. It was originally developed by renowned movable bridge engineer J.A.L. Waddell in 1892 and subsequently refined in partnership with John Lyle Harrington, also an engineer. The firm of Waddell and Harrington designed many varieties of movable bridges in the early twentieth century. The lift span is raised and lowered by steel cables passing over sheaths at the top of steel towers mounted on the span's piers. To ensure easy movement, the span is counterweighted by concrete blocks that travel up and down within the tower framework. The bridge has a functional and symbolic connection with downtown Stillwater, which is represented in the bridge concourse, located at the west approach. This feature includes Classical Revival details, including the open balustrade, light standards, and other concrete elements.
The Stillwater Lift Bridge is significant as a rare surviving example of vertical-lift highway bridge construction of the Waddell and Harrington type. Only six vertical-lift highway bridges were built in Minnesota and Wisconsin prior to World War II. At least five were designed by Waddell and Harrington or successor firms; all were of the standard Waddell and Harrington type. In addition, the bridge and concourse are located within the Stillwater Cultural Landscape District.
In 2012 interim repairs were made to straighten damaged truss members, including on the portal opening, and to restore deteriorated portions of the bridge’s concrete concourse and approach span balustrade. The concrete repairs were carefully completed using treatment methods designed to match the historic concrete, involving use of test panels to match color and surface treatment. The recent repairs allow the bridge to continue to serve vehicular traffic until its scheduled conversion for use as a pedestrian/bicycle trail (anticipated for 2017-18). For further details visit the Lift Bridge project website.
City of Stillwater (Washington County)
Latitude, Longitude: 45.05673917, -92.80227132