In 2015, the MHX Kirkbride Alliance approached Ronstan Tensile Architecture to assist with the design and installation of an anti-throw barrier on the new Kirkbride Bridge. The bridge eliminated the intersection of Kirkbride Road and State Highway 20A, improving traffic patterns by effectively separating local and motorway traffic. In addition to increased efficiency and reduced travel times to and from Auckland Airport, the Kirkbride Road Bridge also minimized the effect of the heavily trafficked highway on the local community of residents and schools and improved the safety of all road users, including pedestrians and cyclists.
One aspect of Ronstan’s involvement in the project included the design and installation of Carl Stahl X-Tend® Tensile Mesh along the sides of the bridge, which would act as a safety feature and deterrent for pedestrians to throw objects from the bridge to the underpass below. To make the barrier more visually appealing and reflect the local culture, the mesh was designed to resemble the traditional Maori canoe, a Waka, moving through waves.
In compliance with Waka Kotahi NZ Transport Agency requirements Ronstan Tensile Architecture used a 1.5mm Carl Stahl X-Tend® stainless steel tensile mesh with a 40mm aperture. The mesh was supplied in individual panels to simplify future maintenance and allow replacement of individual panels. Ronstan utilized form-finding computer analysis of three different ‘typical panels’ to determine the loads applied to the support structure when specifying the mesh panel dimensions.
Each mesh panel was laced to vertical stainless steel structural rods on either side and to Ronstan ACS2 Stainless Steel cables that ran continuously across multiple panels at the top and bottom. The robust cables can accommodate moderate dynamic loads and include a turnbuckle on one end for increased adjustability. The ACS2 cables used on the Kirkbride Bridge were terminated with a toggle jaw fitting, allowing the cables to articulate under load.
Ronstan Tensile Architecture was responsible for the supply and installation of the vertical rods, mesh panels, and horizontal stainless steel cables. This included providing analysis on the mesh under the required design loads and patterning the mesh to suit the Waka and wave shape. Installation took place overnight to reduce the impact on traffic. Ronstan is a global leader in tensile architecture and has extensive experience working with Carl Stahl X-Tend® Mesh – the original stainless tensile mesh. Please feel free to contact us to see how Ronstan can assist with your project.