An inspector who failed to spot a potentially catastrophic crack in a tie girder on the bridge over the Mississippi River between Arkansas and Memphis, Tennessee was fired yesterday after it emerged that he had failed to spot the danger during inspections in 2019 and 2020.
The fracture was spotted by chance on 11 May by engineers from the firm Michael Baker International, which had been contracted to inspect the 48-year-old bridge’s cables and arches.Â Â
They considered it such an immediate threat to life that they called 911, saying "we need to get people off the bridge as soon as possible".Â
Frantic engineers can be heard struggling to make the 911 operator understand the gravity of the situation in calls together lasting more than seven minutes, reports local station, WMC5.
According to the Arkansas Department of Transportation (ARDOT), the failure of the inspector to carry out his duties correctly only came to light when a 2019 drone video taken by Michael Baker International in 2019 showed that the fracture was visible then.
Lorie Tudor, the department’s director, said at a news conference that the inspector did not find the crack because he failed to follow protocol in "literally going inch by inch along that beam and physically inspect every inch".
She added that ARDOT’s inspection process was also at fault and would be overhauled.
The Tennessee Department of Transportation (TDOT), which is responsible for the bridge’s maintenance, announced today that the emergency repair project has been awarded to Kiewit Infrastructure Group, and that work would begin as early as tomorrow.
The repair will be performed in two phases. Both phases will need to be completed before traffic can re-open on the bridge. The department said: "At this point, we are unable to project a re-opening date."
According to TDOT, phase 1 will require the installation of steel plates on each side of the fractured member. Fabrication of the roughly 18,000 lbs. of steel is expected to be complete by Wednesday, 19 May.
Phase 2 design is under way and will be finalised with the help of Kiewit. This will involve removing the damaged section.
The bridge, on Interstate 40, opened in 1973 and cost $57m, or about $250m in today’s money. The architectural design is a continuous cantilevered cable-stayed steel arch, with bedstead endposts.
The New York Times comments: "The shutdown of the bridge has underscored the decay of the nation’s infrastructure and the dangers that it can pose. President Biden has urged Congress to authorise money for an ambitious and expensive proposal to overhaul and upgrade bridges as well as roads, airports, public transportation, railways and ports across America."
Image: The I-40 bridge illuminated by sodium lights (Trevor Birchett/CC BY-SA 4.0)