A microtunnel boring machine (MTBM) called ‘Blanche’ set a new world record when it reached 1496.48 m, the longest ever stretch of pipe laid by the Direct Pipe® tunnelling methodology.
The MTBM is located at Watercare’s Army Bay Wastewater Treatment Plant in Whangaparaoa, New Zealand.
According to the contractor, McConnell Dowell, the installation is a new world record.
The MTBM is being used to replace an old 2.8 km outfall pipeline.
On Friday 13 July, the NZ$6.2 million (AU$5.8 million) Herrenknecht MTBM surpassed the previous record of 1,495 m set in Texas, US last year.
Direct Pipe is a Herrenknecht trademarked MTBM that combines the benefits of microtunnelling and horizontal directional drilling into one machine, allowing the borehole to be excavated as a prefabricated pipeline is installed in one long drive.
The Direct Pipe system has been designed to achieve drive speeds of up to 30 m a day and is generally used to install pipelines under rivers and other large bodies of water in Europe.
“This is the first time the Direct Pipe system has been used in New Zealand,” said McConnell Dowell Project Manager Chris Powell.
“As a consequence we weren’t constrained by traditional applications and were able to use the Direct Pipe system it in ways not explored before.
“We set some pretty high expectations, we learnt much and achieved a real global step-change in how this new tunnelling technology can be used.”
Herrenknecht Asia Pipeline Expert and Area Sales Manager Ben Hayes congratulated McConnell Dowell on using the method to achieve a world record.
“The hands-on site team have been particularly impressive in their ability to adapt and overcome hurdles encountered – along with the support of Herrenknecht site personnel with their considerable Trenchless Technology expertise – to ensure an efficient and safe execution with a technology that was essentially new to them,” said Mr Hayes.
Construction upgrades to the treatment plant began in August 2017 and is expected to be completed in early 2019.
For more information visit the McConnell Dowell website.
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Image supplied by McConnell Dowell