Part of the award-winning Chiswick Park Development, this 120m weathering steel bridge provides a strategic link to the local underground station. We are the lead designers of the bridge, which we believe to be both simple and elegant. It provides a considered response to the functional and aesthetic objectives of the brief…not showy but quietly good looking. By careful choice of materials and structural systems as well as attention to detail in the finishes, the bridge is easy to construct and maintain and will provide its users with, we hope, just the right amount of delight.
The integral arch proposal reduces the embodied carbon through efficient use of structural materials and maximises off-site fabrication, reducing waste and improving quality and safety. This design ethos has been carried through from conception to construction and demolition.
Spanning a railway line, road and nature reserve, the bridge design must address multiple and varied criteria. The form and materiality of the bridge complements the adjacent Chiswick Business Park, Colonial Drive residential development and Gunnersbury Triangle Nature Reserve and the whole design is focused around reducing ongoing maintenance requirements to what is to be a publicly owned structure.
The specific clearance requirements from the road and rail infrastructure inform the geometry of the bridge. Expedition worked closely with Network Rail to explore new approaches to achieve their safety requirements. Construction sequencing involving lifting a single 50m span over the rail track to minimise disruption, and alternative designs for the pedestrian protection system have been included in the design.
In order to derive the best overall design, taking into account the complex site constraints coupled with access requirements and structural optimisation, we developed a Grasshopper 3D model of the bridge. This enabled us to test and modify the bridge through parametric design. For example changes to certain parameters, such as the height of the arch, could be easily incorporated. Through the grasshopper model we were able to automatically generate a modified structural analysis model and 3D drawing model which could be used by a contractor to aid fabrication.
We considered the dynamic behaviour of the bridge early on in the design process and developed a method for a performance based approach to optimise the design. Following on from our experience we wrote a paper ‘Shaped by Walking: Innovative Dynamic Design of Chiswick Park Footbridge’ which was presented at the 5th International Footbridge conference.
The Chiswick Park Footbridge is a demonstration of Expedition’s collaborative approach, utilising expertise in architectural and graphic design from within the Useful Simple Trust to provide an integrated and beautiful proposition.
Project Manager: Stanhope / Beadmans
Main Contractor: Lendlease
Steelwork Fabricator: Severfield UK
Project Value: £7M
Status: In construction – due for completion end of 2018