International Bridge

Contractor – Hardesty & Hanover

The Sault Ste. Marie International Bridge was opened in 1962 and carries two lanes of traffic on I-75 over the St. Marys River between Sault Ste. Marie, MI, and Sault Ste. Marie, ON.  The total length of the bridge is 2.8 miles and consists of multiple spans of steel girders, truss spans, and arch spans.  There are two steel truss arch bridges with suspended decks with a double arch span on the U.S. side of the bridge and a single arch span on the Canadian side.  The arch spans include fracture critical members which must have a biannual hands-on inspection.  The arch spans also include back-spans which are supported on the ends with a pin and link system.

Under renewing three-year contracts between Hardesty & Hanover and the International Bridge Authority (IBA), Fish & Associates, Inc., has performed biannual hands-on fracture critical inspections of the above deck arch members in 2009, 2011, and 2013.  In addition to the fracture-critical inspections, we have performed ultrasonic (UT) and magnetic particle testing (MT) of the pin and link system on the back-spans of the arch in 2009 and 2013.  The inspections are used to determine if there are any internal discontinuities in the pins or external discontinuities in the link bars.


  • Location: Sault Ste. Marie, MI