PC: IABSE
Titled ‘ Tan House Footbridge: Designing with repurposed steel, from early design stages to fabrication ’, the bridge was designed, detailed and fabricated between February 2022 and October 2024, according to the research published in The Structural Engineer. Because the existing steel directly influenced the bridge’s structural form, this flexibility was important. The approach allowed engineers to rethink the bridge design based on the material that was already available. The team used digital design methods to test different options while tracking material use and embodied carbon savings throughout the design process. The project was delivered through a collaboration between Network Rail, WSP UK and Format Engineers. Repurposed steel was central to the design of Tan House Footbridge. This allowed the material itself to influence the design from an early stage rather than being selected after the structure had been developed. Generative digital methods gave the team a flexible, iterative design process. The engineers used generative digital methods to keep the design process flexible and test different options. These tools allowed the team to compare designs while tracking changes in material use and embodied carbon as the bridge developed. The design could then be reviewed and adjusted at each stage towards fabrication. Instead of settling on one design at the outset, the team could assess different possibilities and refine the structure as the available repurposed steel became clearer. Digital tools helped engineers match the design to the available material while continuing to assess the material and embodied carbon savings associated with each option. The design process continued from the early stages through to fabrication. This allowed the team to assess material choices and their effects throughout the development of the bridge. The research states that the team believed Tan House had the lowest embodied carbon of any footbridge Network Rail had constructed on a live site at the time of writing.
A new footbridge in Wokingham, UK, was designed around steel that had already been used or was previously considered unwanted. The team used creative digital techniques to adapt the bridge’s structural form to the available stock of previously unwanted steel.