PURCELL – Cursed by the continuing emergence of unpredictable cracks, state Transportation Department officials Monday abandoned an ambitious goal of completing emergency repairs and reopening the Lexington-Purcell bridge to passenger car traffic within 45 days.
Officials now want all repair and reinforcement work done before reopening the bridge to anyone — a process projected to take 120 days from Feb. 14, when repair work began. The new target date is June 14.
At that point, the bridge will be safe for heavy trucks, as well as cars and pedestrians, said Casey Shell, the Oklahoma Transportation Department’s chief engineer.
“We’d rather stand here before you today and say, ‘We’re going to close this and we’re going to make life miserable for people,’ than stand before you four months later and say, ‘We’re so sorry, 10 people got injured or died,’” said Terri Angier, Transportation Department spokeswoman.
Shell said he feels terrible about the delay — personally having seen the “shock and fear” on the faces of Lexington and Purcell residents when transportation officials discussed the bridge’s closure at town meetings. Resident after resident told about the extreme hardships created by the bridge’s Jan. 31 closure, which turned a short jaunt over the Canadian River that links the two communities into a 40-mile trip.
State transportation officials say they feel even worse because they inadvertently created the current crisis by failing to recognize and tell a Sapulpa contractor who did renovation work on the bridge last year that a few members of one truss were made out of a rare manganese alloy steel.
The contractor welded on brackets that were intended to strengthen the bridge. But welding on manganese alloy steel weakens the material and makes it subject to cracking under stress, Shell said.
Cracks have appeared around last year’s welds.
“That’s the part that I feel horrible about,” Shell said. “It could have been avoided had we known. ... We don’t have a single crack that isn’t associated with a weld out there.”
But the thing that would make transportation officials feel much worse is if the bridge were to collapse. That’s a real danger with fracture-critical bridges like the 76-year-old bridge that joins Purcell and Lexington, because there are not load-bearing redundancies built into the design, Shell said.
“When this one fails, it’s going to be no warning,” he said. “It’s going to break, and that’s going to be the end of it.”
Concerns of more cracking
Ten crack locations had appeared on critical bridge trusses by Feb. 14 when the Transportation Department awarded a two-tiered, incentive-laden $10.8 million repair contract to Manhattan Road & Bridge Co. of Muskogee.
The number of crack locations since has grown to 41 — something transportation engineers say they didn’t expect and fear could grow, especially if traffic is reintroduced to the bridge before all 264 areas weakened by welding have been addressed.
Manhattan’s repair contract called for the construction company to make emergency repairs to the 10 crack-damaged areas within 45 days so the bridge could reopen to passenger car traffic.
The contractor was then to continue reinforcing all 264 areas on the trusses weakened by welding, with an ultimate goal of reopening the bridge to all traffic within 120 days of the start of work.