Emphasis on Aesthetics Led to the Collapse of Tretten Timber Bridge in Norway

Following the collapse of the Tretten Bridge in Norway in August 2022, an official report by the Norwegian Safety Investigation Authority (NSIA) criticized the bridge's design and construction. The bridge, completed in 2012, collapsed while a heavy goods vehicle was crossing, prompting rescue operations for two drivers. The report highlighted insufficient caution during planning, design, inspection, and approval, attributing the collapse to its unconventional design, short construction period, and material choice emphasizing aesthetics over robustness.

The investigation revealed a lack of consideration for block shear failure, a type of fracture, in the design process. Despite earlier identified faults after the collapse of the Perkolo Bridge in 2016, little action was taken by the Norwegian roads authority. The NSIA issued six safety recommendations, emphasizing the need for better regulation, approval processes, and risk management in bridge construction.

The bridge, with a life expectancy of 100 years, was unique in its span length, asymmetry, and combination of wood and steel. The Norwegian Public Roads Administration (NPRA) is implementing measures to enhance bridge safety, including rebuilding similar bridges and addressing closures and restrictions on timber bridges.

About Norwegian Safety Investigation Authority

The Norwegian Safety Investigation Authority (NSIA) is responsible for investigating accidents and serious incidents across various sectors, including aviation, railway, road traffic, marine, and defense. Their investigations aim to uncover factors crucial for accident prevention within these industries. Importantly, the NSIA does not assign blame or liability under criminal or civil law; their focus is solely on understanding the circumstances surrounding accidents to enhance safety measures in transportation and defense.