Bracklinn Falls Footbridge: efficient modular design

The construction and access constraints of the Bracklinn Falls site drove the development of a new modular system and governed the structural and aesthetic design for the new footbridge. The resulting structure consists of perforated panels, formed from single sheets of weathering steel folded into a z-shape. These panels were bolted to cross frames and assembled to create a half through beam that spans 21.4m. The structure was assembled bay-by-bay and push launched along a set of temporary rails, before being jacked onto the permanent bearings.

By using a folding process, the modular system minimised welding and hence fabrication time and energy use. This paper looks at how the multiple constraints of a particular project enabled the design team to deliver a footbridge with an exemplary embodied carbon rating as well as achieving economic, robustness, durability and aesthetic goals.