The Chatham Islands lie 800km off New Zealand’s east coast in the south Pacific Ocean. The archipelago is home to 600 people and one of New Zealand’s most remote communities. The islands are serviced by a single main port which provides a critical lifeline for the community through the provision of imported goods and export earnings. The port is at the end of its structural life and significant upgrades are necessary. The Waitangi Wharf Upgrade includes a reclamation, development of port infrastructure, dredging works and the construction of a breakwater. The NZ Government requested that the Memorial Park Alliance, which comprises government agencies, contractors and consultants, rapidly deliver the upgrade works using an alliance model.
- The remoteness of the site, and the culture of the Chatham Islands, presented some unique characteristic that influenced the project, including;
- A small community, but with real strategic importance to New Zealand;
- The workforce increasing the island population by up to 8% - bringing social challenges and economic opportunities for the local community;
- A need to establish a quarry and concrete batching plant on the island as none existed;
- A need to ship all construction plant and most materials to the island;
- Even more acutely than normal, a need to strike the right balance between robustness of design (given the remote location and desire to minimise maintenance), and capital outlay (given the size of island population);
- Opportunities to leverage off the project for additional infrastructure improvements such as a boat ramp and fishing wharf – taking advantage of the extensive mobilisation required;
The project progressed from concept design, through environmental approvals and detailed design within 12 months; an extremely tight timeframe for a project of this complexity. Extensive community engagement was undertaken throughout the process including requirements at the port and surrounding areas, existing coastal processes, the likely effects of the development and options for mitigation such as beach replenishment and additional options for social and environmental improvements. This built trust and established relationships, very important factors for a project this size impacting on a very small community.
Some specific aspects of the design, tailored to Chatham’s remote context, included;
- Design of the breakwater to accommodate very high return period design events with additional factors of safety resulting in the use of highly interlocking concrete armour units;
- Improved resilience by removing liquefiable sands beneath the reclamation;
- A minimal maintenance design, including:
- Orientating wharf and approach paths to minimise future dredging;
- Extensive use of concrete, including concrete H-piles and panel walls.
- Relocation of kaimoana or seafood from the project area and use of materials conducive to marine growth
- A flexible multi-use port, catering for additional uses such as the islands fishing and tourism requirements.
- Physical model testing of the breakwater and the construction sequence with active involvement from the construction team – important in this exposed and remote location.
This paper will present an overview of the project, and the unique challenges and lessons learned by working in such a remote environment, including:
- The importance of both future-proofing the design and building in robustness to allow for growth and minimise future maintenance that would be impossible or extremely expensive to carry out after demobilisation;
- The relative importance of the project to its community reframed port development by highlighting the critical importance of ports to life as we know it. We consider that there is a substantial, albeit complex, opportunity for the industry to more strongly connect communities to their ports.
- How we must be sensitive to the communities in which we work, and strive to build strong relationships for everyone’s benefit – particularly so with remote projects; and
- That physical model testing can add significant value in fine tuning a design, and providing confidence in the end solution for the funders, the builders and the end users.
Keywords: remote construction, port, breakwater, xbloc, collaboration.