Farm Access for the NIGUP Transmission Line Upgrade
Electrical transmission infrastructure continues to be developed to enhance performance and security in New Zealand. The NIGUP transmission line that operated at 220kV was to be designed and then constructed for 400kV operation. The line runs at 50Hz, is approximately 186 km long and runs from Central north island Whakamaru North Substation to Brownhill switching station. Due to the population in the upper North Island having more than tripled since the inception of the first existing transmission lines, the growing electricity demand required an upgrade to cater to the new residents.
Farm access was required and needed the liaison of nine councils, 300 affected landowners, the community and multiple government agencies. This technical and environmental challenge required careful planning to appease all stakeholders in this large-scale project.
The utility power lines went over multiple terrains requiring various types of access. A small crane required a platform to construct the transmission lines in a grassy field that had recently been immersed in rain. Also, an elevated work platform was used to connect the wiring and required access into a farmland.
How the Bog Mats Were Implemented
Durabase mats acted as both temporary roadway and a platform for transmission related equipment such as large mobile cranes, road trailers and elevated work platforms to do their work on. The thick 105mm DuraBase composite mats was an environmentally friendly method to protect the underlying grassland and the farmland. Acting as a protective layer to prevent bogging and improving ground stability, the mats are easily connected with its interlocking system to form a continuous surface. Evenly spreading the load of the heavy machinery.
Resulting from this project, it was completed on time and on budget. The residents living within the corridor of the upgrades in New Zealand had improvements to their power lines providing extra security and performance. Minimal remediation was required and the mats could be gathered effortlessly.
The project was such a success, the Resources Minister of New Zealand had this to say “The North Island Grid Upgrade Project has provided greater electricity supply security to the upper North Island and will ensure that as cities and communities grow our electricity infrastructure will be able to meet the increase in demand.”
—Phil Heatley, New Zealand Energy and Resources Minister