The Fern Hollow Bridge was showing significant rust corrosion in early October 2021, mere months before the bridge collapsed on January 28. In a partially redacted report obtained by the Pittsburgh Post-Gazette from the Pennsylvania Department of Transportation in response to a Right to Know request, inspectors found holes in the steel support legs, a decaying bridge deck and severed steel cross-beams.
Although the findings detail a long list of decaying conditions, there were no calls for immediate repairs.
The report raises questions about what the city of Pittsburgh and PennDOT could have done to prevent the bridge's failure, given its deteriorating condition.
Pittsburgh City Councilman Corey O’Connor said he was unfamiliar with the inspection findings that were provided to him by the Post-Gazette. “Even those details you gave me, I was never privy to that” he said, adding that he hoped the city will be more transparent with such information in the future.
“The safety is the priority,” O'Connor said.
According to the Post-Gazette, a spokesman for the Green Tree engineering firm that performed the inspection said it could not comment because there is still an active investigation into the bridge’s collapse.
Even with evidence that the bridge’s steel structural support legs and cross-bracing were deteriorating, inspectors kept the 26-ton weight limit that had been in place since 2014, writing: “Because the condition of the main load carrying members has not changed significantly, the 2014 Load Rating Analysis is still valid.”
According to the Post-Gazette, several engineering experts who were contacted said they were troubled by the conclusions, and the load rating should have been re-examined.
“Someone above [the inspectors] should have taken this report and said, ‘We need to do some additional analysis,’ ” said Roberto Leon, a construction engineering professor at Virginia Tech, who reviewed the inspection report at the Post-Gazette’s request.
The sections of the report with the data that led to the 26-ton weight limit were redacted by PennDOT.
Deterioration of the bridge was detailed in the report, including to the deck concrete, lower cross-bracing, steel legs and bolt loss on the inside of the girder splice plate. According to the report, the deck concrete was impacted by water seeping through the deck and onto the steel superstructure underneath, including the four support legs. This water was often chlorine-laden from melted snow.
The loss of up to 50% of the bolts inside the girder splice plate could also impact the carrying capacity of the bridge, according to the Post-Gazette.
The release of the inspection report continues to draw concern from experts.
“The inspection itself is good,” said Leon. “But there are troubling signs here that should have gotten people into action.”
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Source: Pittsburgh Post-Gazette
