The need for efficient, timely and value-led infrastructure delivery grows daily as economic conditions tighten. Tonkin + Taylor has a rich history of technical excellence spanning more than 60 years, and is navigating these challenging conditions by going back to basics – innovatively delivering solutions-focused projects in collaboration with clients and alliance partners. The result? Projects delivered under budget with impressive time efficiency, and reduced carbon emissions. 

Te Ara Tupua Shared Cycleway – Keeping Wellington Connected on a Budget

Te Ara Tupua, a New Zealand Transport Agency Waka Kotahi project, is being delivered by the Te Ara Tupua Alliance. The alliance is comprised of Tonkin + Taylor, Downer Group NZ, HEB Construction, NZ Transport Agency Waka Kotahi, and iwi partners Taranaki Whānui ki te Upoko o te Ika and Ngāti Toa Rangatira, who were tasked with improving transport resilience to protect the rail and road, while also creating a safe walking and cycling connection between Wellington and Lower Hutt. Safety for multimodal transport users is one of the key drivers for the project, sitting alongside positive biodiversity outcomes and more resilient infrastructure for the people of Pōneke.

This saw the development of seawalls, rock and concrete unit revetments, shared paths, offshore habitats, and landings, which saw the team achieve both global and New Zealand firsts.  

The team developed innovative uses for the interlocking single‑layer concrete armour units. Using pattern‑placed interlocking concrete blocks reduces greenhouse gas emissions compared to alternatives. This is due to the lower volume of armour needed, reduced transport emissions of material to the site, and a faster construction program – not to mention significant cost savings with a solution that improves biodiversity within the harbour environment. 

Ecological enhancements incorporated into these blocks were gifted the name ‘Te Ripowai’ by Taranaki Whānui artist Len Hetet, who worked alongside project designers, engineers and ecologists to mimic the rocky foreshore that will encourage marine life to attach to the surface of the blocks.

The team found that the uniform nature of the interlocking blocks didn’t align with the natural character of the landscape and consent requirements, so the standard units were modified to fit a local context, without increasing cost.  

The stability of single-layer concrete interlocking blocks is generally tested under storm wave conditions; however, the units have limited application in seismically active regions, so complementary physical and digital models were used to assess individual components and combined performance. 

This is the first time globally that seismic performance has been considered in the design of these specific units, and the first time this multimodel approach has been adopted. 

Tom Shand, Tonkin + Taylor Principal Coastal Engineer, says that with constraints to both funding and the consideration of the construction footprint, the team worked hard to bring the innovations that ultimately allowed this project to proceed.   

‘I’m so proud of the fact that not only were these world-firsts that saved money, but they also resulted in improved project results by combining engineering resilience with cultural, ecological and landscape outcomes,’ he says.

State Highway 25A Taparahi Bridge – Reconnecting Coromandel communities

The New Zealand Transport Agency Waka Kotahi engaged Tonkin + Taylor to design the supporting elements of a three-span bridge in collaboration with Beca, and the McConnell Dowell and Fulton Hogan joint venture. The project began under emergency conditions after major storm events in January, 2023.

The need to reconnect transport routes for the community quickly and safely was clear, and the project kicked off with a strong set of guiding principles: simple, proven, materials-led, and ‘safest is fastest’. 

The project was delivered in just seven months, setting a benchmark for the infrastructure industry, and contributing an estimated $69-million increase in tourism expenditure for delighted locals and holidaymakers.

The bridge design was delivered in half the standard time, and the bridge structure was delivered in a quarter of the standard time, resulting in the completion of the bridge three months ahead of schedule – no easy feat.

Jo Wilton,  New Zealand Transport Agency Waka Kotahi Regional Manager, highlights the collaborative efforts among everyone involved: ‘It didn’t matter who you worked for, everyone had one goal: get this bridge open as quickly as we can. It’s one of those things where you set yourself an impossible goal and then you achieve it, and the feeling is “Yes! See, we’ve done it!”’

It’s safe to say the State Highway 25A project positively influences public perceptions of the infrastructure industry. Industry leaders and politicians have noted its success, and have expressed keen interest in replicating this model for future projects.

Mark Foster, Tonkin + Taylor Engineer, says that leading the design team on State Highway 25A was a career highlight.  

‘Every single person and organisation involved was so focused on our ambitious target, and it resulted in an amazing atmosphere of urgency and collaboration among the team. I still can’t quite believe we pulled it off!’