The statement puts a total cost of up to US$9 million on the package of temporary and permanent repairs.
Minister of transportation Steven Del Duca and minister of northern development and mines Michael Gravelle said:
“Following the closure, two firms were contracted to test the bolts from the bridge. The testing confirmed that the bolts broke due to overloading and not due to any flaw in the bolts themselves.
A thorough engineering analysis was then conducted by ministry bridge engineers and an independent engineering consultant to determine the cause of the malfunction. These analyses were conducted independently and reached the same conclusion.
“The engineering reviews found that three main factors led to the malfunction: first was the design of the shoe plate and its flexibility; second was a lack of rotation in the bearing that was constructed; and third was improperly tightened bolts attaching the girder to the shoe plate. When combined, these three factors produced the malfunction. Neither cold temperatures nor wind contributed to the closure.
“A new permanent retrofit design has been developed to address the issues identified by the engineering reviews. This permanent retrofit will ensure that the Nipigon River Bridge functions safely for road users throughout its intended useful life. This design will be reviewed by Associated Engineering (Ont.) and ministry bridge engineers and will also be applied to the south portion of the bridge, where construction is progressing well. Preliminary estimates for the initial repair work in February and the final repair to be implemented are between $8 and $12 million [US$6-9 million].”