Waitangi wharf – Chatham islands enterprise trust and council

This 2018 CCNZ Award winning project was an Alliance model between, Downer and HEB. They were tasked to design and construct a new wharf for the Chatham Islands to replace their old and degraded wharf. The wharf is a critical lifeline for the Islands, providing the only port for commercial fishing operations, export and import freight operations, and shipping of all consumer items for the community. The scope of work included:

  • Demolition of the existing 100m long, 12m wide concrete and timber wharf.
  • Dredging of over 7,000m2 of harbour and seabed to improve berthing for vessels.
  • Design and construction of a 185m-long breakwater using 3,300 of the Xbloc interlocking concrete armouring blocks.
  • Design and construction of two 6m-high concrete walls and backfilling behind them by the placement of 100,000m3 of quarried basalt rock
  • Design and construction of a 350mm-thick 120m x 120m new concrete hardstand for the traversable wharf area. This included installation of new utility services for stormwater, sewer, potable water, electricity, lighting, and fuel lines.
  • Design and construction of new facilities for livestock transportation including holding pens and allocated stock race, a new building and a separate fisherman’s wharf facility.
Rangitoto island wharf replacement – department of conservation

Downer was awarded the construction contract for the new approach walkway (85m x 2.4m, 16 piles), wharf head (39m x 11m, 21 piles), fendering works and removal of the existing timber wharf. The new wharf is founded on 600mm and 760mm diameter steel cased reinforced concrete piles. The steel casings are bottom-driven to the underlying basalt rock or to a “set” within the firm sands with precast beams subsequently placed to span between the piles. The wharf decking consists of pre-stressed concrete double tee and flat slab units. All precast elements were designed for stitch cast connections to minimise both the on-site formwork and environmental risk from concrete spills.

Westhaven promenade and cycle way

The promenade project was approximately 2km in length, linking the Western Bays and Harbour Bridge to Wynyard Quarter for pedestrians and cyclists. The works included three separable portions, that covered off, demolition, excavation, boardwalk piling, seawall stabilisation, piling, concrete and precast work, reinforcing and structural steel, carpentry, drainage, electrical works, paving and kerbing, planting, furniture and fittings.