West Wind Farm

Meridian Energy / OPUS / Tonkin & Taylor (2006) & WWTL – Meridian Energy / BECA (2007)

For this project we had difficult terrain to contend with and very fractured rock due to the close proximity to major fault lines. Compounding this was the very high wind factor and extreme weather conditions in which we were operating.

Project scope

For the wind farm project we drilled more than 30 holes across the site on the ridgelines where the turbines were to be sited. Further bores were drilled for the wharf structure on the beach at Oteranga Bay where the submarine power cables come ashore and other investigations including inclined cored holes for suitable quarry material were carried out across the site.

For the transmission line project we carried out a number of holes at possible tower locations to assist with design of a new transmission line to carry the power from the Wind Farm to the national grid.

Complicating factors and solutions

Limited access, steep terrain, wet slippery conditions and very high winds were all complicating factors to overcome. The rock was very fractured due to the proximity of the main fault line and required the skills we have developed in working with Wellingtons’ difficult ground conditions to successfully core the highly fractured weathered greywacke.

For the transmission line project no new roading could be constructed across the steep terrain, meaning careful planning and complicated logistics to get to the proposed tower locations. For example some sites required scaffold to fly the gear onto due to the steepness of the terrain.

Helicopter access

One of our helicopter portable units was used to reach the bore locations high up on the hillside that were only accessible by air. Due to the proximity of the national grid safety of both the network and all personnel was paramount and required meticulous planning before getting off the ground. This was made easier by our helicopter operator who routinely flies maintenance crews on live line work in and around the lines.