The opportunity to work on a massive, transformational project that redefines the way a city connects, travels and moves doesn’t come along often. For Wataru Okada, Technical Principal – Geotechnical and Tunnels, WSP Opus, working on Auckland’s Waterview tunnel was a dream come true.

As the largest infrastructure project in New Zealand there were numerous milestones, but what really stands out for Wataru, who was onsite during the construction phase, was the teamwork. “

There was input from so many specialists and experts in their field; civil, architectural, geotechnical, structural, M&E. When we designed each element our work was checked by multi-disciplinary team leaders and during that process we’d discuss and coordinate with other experts. The end product is a combination of the input from different disciplines, and when you see that come to fruition it’s quite satisfying and rewarding,” he says. “Every time we completed a
package of design there was a real sense of achievement.”

When Alice began drilling a huge cheer went up from everyone on site. The same happened when we finished drilling – it was a milestone achievement.

Excavation required the use of a Tunnel Boring Machine (TBM) and the sheer scale of the work required a big machine. Enter Alice, the 10th largest TBM in the world and the biggest ever used in the Southern Hemisphere at the timeof the project.

Alice was 87m long, weighed 2400 tonnes and featured a 14.4m diameter rotating cutting head attached to the front of a 12m long shield. To construct the project’s twin road tunnel, Alice had to be turned around 180 degrees at the end of the first drive in order to drive the second tunnel returning back to the southern portal. Wataru says the experience of seeing Alice in action was indescribable.

“It was a massive moment to see this humongous piece of machinery start work. When Alice began drilling a huge cheer went up from everyone on site. The same happened when we finished drilling – it was a milestone achievement.”

Alice’s journey would have been abruptly interrupted if it hadn’t been for some smart thinking from the Alliance team. Wataru says the team identified a lost core barrel – a steel tube – that would have caught in and mangled Alice, causing significant delays and potentially halting the project. Removal of the steel barrel was a mini-project in itself but allowed Alice to continue without issue.

“When we finally got the steel out it was cut into sections. I know that a piece was mounted on a stand and now sits in a senior project member’s home as a reminder.”

Waterview tunnel opened in July 2017, and Wataru was one of more than 60,000 people who walked through on the open days. A year later he’s still immensely proud of what was achieved.

“I get such positive feedback from people about how it’s improved their travel. When I take a taxi the driver always tells me how much Waterview benefits them. It’s so good to see people happy with what we produced.”