Known as ‘Piper’, the MTBM was extracted from 3 m under the seabed using specialist mass flow excavation equipment during a rare weather window in Hokitika, on the west coast of New Zealand’s South Island.
Piper was then slung under a custom-made pontoon and towed 18 nautical miles (33 km) back to Greymouth.
McConnell Dowell said the pontoon was designed by the company’s in-house temporary works team and fabricated by its mechanical team.
The pontoon was also used by McConnell Dowell on the recent Snells Algies Outfall and Army Bay Ocean Outfall projects.
The Westland project involved the construction of 800 m of new trenchless pipeline using the Direct Pipe® system, with the pipeline part of the overall scheme to re-direct waste flows from discharging into the Hokitika River and into a more acceptable location.
For more information visit the McConnell Dowell website.