Vector identified a need to improve the reliability of the K05 South Head Road 11kV feeder for customers in the Helensville area. Northpower was selected to deliver a targeted overhead refurbishment programme to modernise this critical section of the local power network and improve service reliability for the Helensville community.

The project strengthened infrastructure while maintaining supply for customers wherever possible. Northpower was responsible for planning and delivering the full scope of works, co-ordinating specialist resources, and managing outages to minimise disruption during construction.

Overhead line refurbishment requires highly specialised technical skills and careful sequencing of work. First, crews prepared the site through traffic management, vegetation management and access planning along the K05 corridor. Conductors were then progressively removed and replaced, alongside the replacement of poles and crossarms to restore the structural integrity of the line.

The use of the new insulated conductor CCT significantly reduces the likelihood of transient faults caused by vegetation or animals coming into contact with the lines. This also reduces the risk of electrical shock for both animals and humans. However, a key challenge associated with this conductor is its increased weight. As a result, stronger poles are required, along with additional stay wires, upgraded crossarms, and specialised CCT clamps to safely and effectively support the conductors.

The project also involved complex civil works, including excavation for pole replacements using hydrovac technology and close co-ordination between overhead, civil and vegetation teams. Once installation was complete, sites were reinstated and vegetation trimmed to reduce the likelihood of future network faults.

Safety and risk management were central to project delivery due to the scale of works and the location along an active road corridor. Workforce and public safety were managed through detailed outage planning, traffic management and the use of specialist equipment.

To minimise disruption to the community, generators were used to supply power to the majority of customers during planned outages. This approach helped keep services operating while essential upgrades were completed. The project required co-ordinated effort across Northpower’s crews, with additional support from specialised hauling resources mobilised from the Hamilton depot when required.