InTrans / Aug 14, 2018

Load Testing and Rehabilitation of the Sioux Narrows Bridge

Built of B.C. Douglas Fir in 1936, the Sioux Narrows Bridge supports a main clear span of 64 m and is believed to be the largest single span wood highway bridge in North America. Originally it was proposed that the bridge be replaced in 1975 but demolition was delayed following an extensive investigation by students who concluded that the structure could be rehabilitated. Subsequently MTO initiated an in-depth investigation, including inspection, analysis and field testing which confirmed that the existing bridge could be maintained.

The objective of this report is to document the extensive work performed by MTO. This includes a detailed field inspection, numerous structural analysis and field testing, as well as a record of the successful replacement of the old nailed laminated deck with a new prestressed wood deck in 1982.