Transpower 400kV Line

The project would deliver a new power line link from Whakamaru to Auckland and this required the design, supply and construction of a 400kV-capable overhead line of around 186km in length. A total of 426 towers were to be erected on over 300 landowners’ properties and with each tower weighing up to 60 tonnes and the height of a 15-storey building, the foundations had to be robust.

Grouting Services was successful in securing the subcontract to undertake specialist foundation strengthening works which involved drilling and low pressure grouting at individual tower sites to treat tomo conditions and assist in the consolidation of the ground without the threat of hydro-fracture. A total of 25 sites were completed involving some 18km of drilling and 1,600 cubic metres of injection grouting.