By reassessing wind-induced demands in a more data-driven and evidence-based way, COWI in the UK & Ireland has delivered an important advancement in structural engineering for BEAR Scotland on behalf of Transport Scotland. This approach avoided the need for extensive strengthening works, resulting in a reduction of 240 metric ton of embodied carbon emissions—the equivalent of driving a typical car 1.2 million km, or around the Earth 30 times.
The Forth Road Bridge’s Critical Elements Program (CEP) was launched in response to a 2015 truss end link failure, with earlier assessments having identified overstresses in key structural members and the need for widespread strengthening of much of the stiffening truss.
Global consulting firm COWI, acting as Independent Checker, combined high-resolution RWDI wind tunnel testing with state-of-the-art GNSS-based monitoring data collected during eight major storms between 2021 and 2023.
“This project exemplifies the future of infrastructure management—where real-time data and intelligent modeling replace unnecessary construction,” said Andy Sloan, Managing Director, COWI UK & Ireland. “Not only have we ensured the bridge’s safety, we’ve also significantly reduced carbon impact.”
The reassessment revealed that internal forces and modal accelerations were significantly lower than previously assessed, with the structure demonstrating higher net damping at moderate wind speeds, likely due to articulation friction. As a result, the number of overstressed top lateral members dropped from 184 to just eight, and over 120 metric tons of strengthening steelwork will no longer be needed.
Beyond the technical success, the project highlights a powerful message: that intelligent, evidence-based engineering can extend the life of existing infrastructure responsibly and sustainably. As global infrastructure ages, this approach offers a compelling model for others to follow: build nothing, if nothing needs building.