We recently collaborated with bridge engineers from Holmes Consulting and contractor MacDow on a competitive design tender for a new opening footbridge in Whangarei. The bridge will form a new entry into the city from the south, linking up new recreational walking and cycling routes along the river while retaining river access for small vessels.
The gently curved plan form of our team’s design allows for good flow between east and west banks, with a 3m width accommodating pedestrians and cyclists. The bridge was designed to be low-profile and visually open; pre-cast concrete deck sections on a slender steel box girder, combined with steel balustrades and a timber leaning rail give the bridge a simplicity that accentuates the pylons of the opening section.
Referencing the history of Whangarei as a place where the northern and southern tribes often clashed (the name Whangarei translates as ‘laying in wait’; the Waiarohia stream is named after a significant battle), our concept for the bridge form was based on the taiaha (fighting stick) which is used in the wero (challenge) of the traditional Maori welcoming ceremony. As the bridge swings open, or as you move towards the bridge along the walkway, the taiaha pylons appear to lock together in challenge.
In addition to the bridge architecture, Isthmus produced the design visualisations:
At the broader scale bridges are a key urban design move that can ‘unlock’ a project by connecting communities and assisting movement through the landscape, whether by vehicle, bike or walking.
We work with materials and the composition of structural elements to develop designs that respond to their context, explore a narrative and offer high levels of visual, functional and recreational amenity.
Our bridge pamphlet profiles four projects that include a signature bridge element, or a space under a bridge, within the overall spatial design. These projects have been urban design-led and have involved a collaborative process with specialist engineers working together to achieve a shared vision.
1. TE PURU BRIDGE: Manukau City Council. 2006-2010
2. ONEHUNGA FORESHORE BRIDGE: Auckland Council + NZTA 2010 – current
3. ALBANY HIGHWAY – DAYS BRIDGE: Auckland Transport 2011 – current
4. SEART: SYLVIA PARK: Kiwi Income Property Trust 2001-2007
download the pdf:
Perspective for Resource Consent: The bridge will be a distinctive gateway on State Highway 20, with a different character experienced when travelling east and west.
As a signature element of the Onehunga Foreshore Restoration, the pedestrian and cycle bridge will become a key linking element between the existing Onehunga Bay Reserve and the new coastal parkland and beaches. It will form part of a recreational loop and connect with the Waikaraka Cycleway and the future Taylors Bay coastal walkway. The project is currently making its way through Auckland Council’s Resource Consent process.
Plan for Resource Consent: The project seeks to re-establish the natural character of Onehunga Bay through the creation of 6.8ha of usable parkland and rocky promontories as well as dynamically stable gravel and sandy beaches.
The bridge design was led by Isthmus who developed the key concept and aesthetic elements of the proposal within the parameters determined by the Principals Requirements. This included the need to balance the gateway directive with the need to ‘fit’ and being keeping with the Onehunga environment and to completely span the motorway. A key component of the concept was for the bridge to belong to the land and therefore the Onehunga community and this differentiated it from the series of cable stay bridges currently on the motorway network. With the concept embedded Isthmus worked with the URS bridge engineers to develop a steel truss system that could be clad. Similarly Isthmus worked with Tonkin and Taylor Civil and Geotechnical engineers to develop the form of the abutment mound and degree of cladding.