HIGHLAND HEIGHTS, Ky. (AP) – An engineering team was dispatched Monday to check for weaknesses in steel used to construct two Ohio River bridges on Interstate 275, some 5 miles east of Cincinnati.

Kentucky Transportation Cabinet spokesman Chuck Wolfe said tests are under way to ensure the safety of the Combs-Hehl twin bridges after laboratory tests indicated steel used in the three “splice plates” didn’t meet the state’s specifications for strength.

Cracks were discovered in the plates during an inspection the winter of 2006. The cracks were monitored until January 2008 when engineers recommended replacement of the plates. That work was completed on June 1.

Wolfe said no other cracks have been found in the bridges. Engineers from Kentucky and Ohio transportation agencies and the Federal Highway Administration recommended that the remaining steel in the bridges be tested. Contractors from Louisville have been hired to conduct those tests.

“We believe the bridges are safe, or else they would be closed,” Wolfe said Monday.

One lane was closed Monday on each of the three-lane bridges to allow engineers to conduct the tests and to complete a broader inspection. Work on the bridges, which were built in 1979, is expected to take at least four weeks.