Christopher Cassaniti Bridge

Structural Designer


Client Name



Sydney, Australia

KI Studio

Arenco & Daracon



A key public transport connection within a new brown field redevelopment. Twisting fabricated box sections are understood to be unique in this helical bridge. Overall tonnage was achieved through optimisation of each plate thickness throughout the helix shape.

Submitted in 2021

Judge's comment:

Through structural ingenuity and advanced parametric analysis, the design and construction team have produced a stunning, multi-span, materially efficient bridge. 

The complex spatial structural shape was defined by the workflow and is wonderfully fluid. It responded not only to the hard geometric constraints imposed by vertical road clearances, maximum gradients, topography, and possible support locations but also considered user experience and integration with the natural landscape. The result is a fluid and playful alignment snaking its way over the motorway. 

The use of twisting fabricated box sections is understood to be unique in a helical bridge, allowing the engineers to optimise every plate thickness to respond to its demand. Digital design workflows were used to optimise alignment, geometry and performance to ensure the most effective material usage and reduce the embodied energy of the structure. The application of parametric modelling also facilitated the process to assemble components on site.

An engineering led approach resulting in a beautifully designed minimalist structure.

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