In Norway, four wooden bridges have been fully reopened after inspections and remedial work, while several other bridges have been opened for reduced loads.
The Norwegian Public Roads Administration (Statens Vegvesen) said that it is working to solve the challenges related to the bridges that are still closed after the collapse of a bridge in Tretten last August. The most likely cause of the collapse was overload.
Work continues by consultants, suppliers, the NTNU – Norwegian University of Science and Technology - and other academic institutions that have expertise in wooden truss bridge design, said Gunnar Eiterjord, head of Statens Vegvesen’s operations and maintenance division.
According to Norwegian media reports at the time, the 150m-long, 10m-wide Tretten Bridge - only a decade old - broke in two, collapsing into the river stranding two vehicles and their occupants. There were no casualties or injuries in the early morning accident on August 15, but one driver was airlifted to safety.
Late last year, a preliminary investigation by the Norwegian Safety Investigation Authority suggested that the cause of the Tretten collapse was "a break in one of the diagonals in the main span towards the western river foundation". This could have caused overloading and unloading of other elements in the truss, leading to a failure.