Ind. agency: Closed bridge’s steel more brittle

An Indiana Department of Transportation spokesman says the steel used for a closed bridge on Interstate 64 that connects Indiana and Louisville, Ky., is less resistant to cracking than steel used today.

Agency spokesman Will Wingfield says the steel known as “T1” was an innovative material when the bridge was built in the 1960s, but there have since been advances in toughness and crack resistance. He also says the tied-arch bridge was classified as “fracture critical,” which means a failure of one component can jeopardize the entire bridge.

The Sherman Minton Bridge was closed suddenly Friday after a routine inspection found a crack. The bridge carries some 80,000 vehicles a day over the Ohio River. Wingfield says it will take at least three weeks to diagnose the problem.