Web Tower: Aug – Oct ’19
Web Tower: Aug – Oct ’19

Glenn Edwards’ lifetime of trenchless adventures

Glenn Edwards, one of Interflow New Zealand’s longest serving employees and an icon of the Australasian Trenchless Technology industry, retired from his role in July 2017. Trenchless Australasia speaks to Mr Edwards about some of the milestones and memories from his 50-years in the no-dig sector.

Mr Edwards, who has served as Interflow New Zealand Regional Manager for the past 10 years, retired in July following a career that extends back to 1967 – before the trenchless pipeline rehabilitation industry had even commenced.

Over his career, Mr Edwards’ achievements have included introducing cured-in-place pipe (CIPP) lining in countries around the world, and developing innovations that have extended the possibilities for the industry. But it is in his home country of New Zealand – over the last decade – that he has delivered his proudest achievements.

Christchurch earthquakes

Mr Edwards was first exposed to spiral wound liners when he started with Interflow New Zealand. He has since developed the potential of these liners for New Zealand conditions, including meeting the requirements for rehabilitation of the sewers damaged by Christchurch’s tragic earthquakes in 2010 and 2011.

Speaking on the work in Christchurch, Mr Edwards says, “Conditions in Christchurch were about the most difficult I’ve ever faced for liner installation. The condition of the damaged sewers was challenging enough, but add to that the heavy infiltration of freezing groundwater, and manhole locations in the middle of roads that were also being repaired.

“Then there was the design specifications, which meant we were required to install liners that were much stronger and stiffer than ever previously carried out. Spiral wound liners have inherent benefits in these conditions as heating is not part of the installation process.”

Innovation in CIPP lining was also needed in Christchurch for the small diameter connections that were part of the Interflow contracts that Mr Edwards managed.

“Installation of small diameter CIPP in sub-zero temperatures, with heavy infiltration meant developments were needed in equipment, materials and work methods. But Interflow is a company with a culture of innovation, so we were even able to achieve some real breakthroughs in CIPP lining,” he says.

Humble beginnings

Mr Edwards’ career started as a drain layer in 1967. His first introduction to Trenchless Technology was in 1980 when, recuperating from a worksite injury, he was offered a month’s work managing a contract to cement line cast iron water mains.

He stayed with the company for seven years and over that time, he expanded their trenchless portfolio into rehabilitation of large diameter water mains. He was also responsible for introducing leak detection technology he had sourced while attending the first ever International Society for Trenchless Technology (ISTT) International No-Dig Conference, in London in 1985.

While at the conference he met Eric Wood, who is credited with inventing CIPP technology. They kept in touch, meeting at conferences around the world until Eric’s untimely death in a plane crash in 1994.

In 1987 Glenn joined AC Tipping Maintenance Limited, managing the company’s pipeline rehabilitation projects. They included major works sliplining large diameter water mains with fibreglass, steel and polyethylene pipelines around Australia and New Zealand.

In 1988 Mr Edwards saw the introduction of the U-Liner, a polyethylene fold-and-form liner. A breakthrough with this technology was Mr Edwards’ development of remote cutters suitable for making house service line connections to lined 150 mm sewers. These liners were previously only available for 200 mm diameter sewers and larger, which meant lining 150 mm sewers, the most common size in Australia and New Zealand, could not be undertaken. Having the cutter available in 150 mm sewers opened up possibilities, not just for U-Liner but for CIPP, which had started to be used in Australia.

While based in Sydney at the time, Mr Edwards was able to expand AC Tipping’s reach, carrying out many sewer lining projects in Singapore and Hong Kong.

In 1994 Glenn and a business partner purchased AC Tipping’s Maintenance Division and formed Pacific Pipeliners. They extended the company’s business, installing U-Liner and CIPP liners in Australia, New Zealand and around the Pacific.

Pacific Pipelines was heavily involved in Sydney Water’s early programs to reduce infiltration and inflow into sewers – to keep the beaches clean – importing equipment for polyurethane grout sealing of leaking sewers.

Sanipore flood grouting was another innovation Pacific Pipelines introduced to Australia. One project requiring innovation was the lining of the vertical downpipes in the Sydney Town Hall.

In 2002 Pacific Pipeliners was purchased by Thiess Limited, persuading Mr Edwards to make his first attempt at retirement. It didn’t last long, and less than a year later he was back in the Trenchless Technology industry.

With his worldwide network of contacts, Mr Edwards was recruited to the position of International Sales Director by Masterliner Inc.

Masterliner Inc was a manufacturer of equipment for CIPP lining and Glenn spent the next four years based in the US but travelling to Canada, Europe and the Middle East providing training and support to Masterliner’s customers. This position gave Mr Edwards experience solving the widest range of lining problems in the widest range of conditions.


In 2007 Mr Edwards decided it was time to return home to New Zealand, and he accepted the position of Business Development Manager with Interflow. Based in Auckland, he later became the Regional Manager, responsible for an expanding number of work crews.

Under Mr Edwards’ management Interflow’s business developed to become New Zealand’s largest pipeline rehabilitation contractor. He was able to apply his worldwide experience to extend the capabilities of spiral wound lining, making it the most installed type of liner in New Zealand as well as Australia.

Mr Edwards is now in semi-retirement at his home in northern New Zealand and has more time to devote to his passion for deep sea fishing. He still consults to Interflow, providing valuable advice to the company as well as its clients around the country.

For Mr Edwards, Trenchless Technology has been a fascinating industry, providing constant changes and challenges. He rates the Australian and New Zealand industry as being at the forefront of world industry development – a position to which he has made an important contribution.

This article was featured in the September edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet, or mobile device, click here.

For more information visit the Interflow website.

If you have a project you would like featured in Trenchless Australasia contact Managing Editor Nick Lovering at nlovering@gs-press.com.au

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