In 2022, the project reached some of its most technically challenging and significant milestones. The TBM successfully completed a 1.5-kilometre drive beneath the Manukau Harbour — a rare and complex feat in tunnelling, requiring exceptional precision and risk management. Later in the year, the machine passed beneath Hillsborough Ridge at a depth of around 100 metres, the deepest point along the route. These achievements highlighted both the capability of the technology and the expertise of the project team.