Hobson Street, Substation, Auckland

Transpower New Zealand together with Vector is constructing a new substation at Hobson Street in Central Auckland. The new substation will connect the new underground cable circuit being installed as part of the North Auckland and Northland Grid Upgrade Project (NAN project) and will help reinforce electricity supply to Auckland’s CBD.

Ancor Loc was engaged by Hawkins Infrastructure as the preferred anchoring contractor on this difficult design and construct project. A variety of ground anchors were specified to enable demolition of the existing structure and excavation to allow for the new substation. The unknown details of surrounding ground conditions meant a strict testing and monitoring process was used with the first stages of installation. This was used to determine the effectiveness, behaviour and holding capacity of ground anchors, and included several creep tests held for a 48-hour long period. The process was overseen by the design engineers BECA and Aurecon, with all anchors meeting test criteria and incorporated within the construction, some as permanent production anchors and some temporary. Ancor Loc’s success was largely due to our unique experience in tight access drilling, including rock anchors drilled with the confinement of a new tunnel using a remote powered tight access drill rig. In total 75 Grouted 1030 mpa and 500 mpa All Thread Bar Anchors were installed over five stages of construction.