In order to make the microtunnelling industry more competitive and able to take on even more jobs, the committed team from Edge Underground – part of OptionX Group – uses its expertise and drive to set a benchmark in the industry, pushing the limitations of current equipment capabilities by modifying and designing new equipment that is more capable. This culture of innovation has led to the development of the air hammer, a drilling tool that addresses the challenges of drilling in very hard rock, providing microtunnelling contractors a solution that increases rates of successful pipeline installation, while still maintaining accuracy, productivity and efficiency.

Stuart Harrison, CEO of OptionX Group, said the team understands microtunnelling – and trenchless in general – is a relatively new method of pipeline installation, and there is room for it to evolve and improve to make it a more appealing choice at the design stage of a project. 

“We are very much shaping the future of the industry, finding ways to improve equipment so that it is more capable to not only handle the various ground conditions that are out there, but to do it more reliably, more consistently,” Mr Harrison said.

“We understand that trenchless has its limitations and we don’t want to see projects where people are feeling let down by it. 

“When trenchless has an issue, everyone holds their breath, they’re nervous, wondering what that means for the project – can the contractor do it, will the project timeframe blow out? These are all the things that we know are prohibitive to designers actually making a trenchless design.”

Mr Harrison said this is why the team is always looking for ways to continually improve.

“When we think we’re doing something well, it doesn’t mean we stop looking at it. Even if something is not a problem, we ask if we can do it better,” Mr Harrison said.

“As a team we’re all very much passionate about taking everything to a new level. We have guys who wake up in the middle of the night with an idea, and that’s how much they’re into what they do.

“When it comes to designing new equipment or modifying current equipment, the team has a deep breadth of knowledge and expertise to draw on, and they’re diligent in testing and trialling off site. This means that when it is finally used on site, it has been proven and there is no risk to the project.”

The air hammer

Very hard rock has traditionally posed a problem for microtunnelling machines, with most tooling struggling to successfully drill through it to install a pipeline to specifications. Because of this, most contractors turn down projects where the geotechnical information has identified this ground condition, or stop a job part way through when they unexpectedly hit very hard ground. 

With more projects requiring drilling rock on fine grades and the lack of options available that had high rates of success and/or were time and cost efficient, Edge Underground was inspired to come up with a solution – the air hammer. 

The technology uses air-driven hammers (similar to vertical DTH heads) on Edge Underground’s AXIS laser-guided system. This system is a new technology to the microtunnelling market, enabling drilling in very high strength rock, and has been proven on Yarra Valley Water’s Donnybrook Link Sewer Stage 2 project. 

“It can be operated via the next generation AXIS drill rods with a power enhancing driver, and has been tested and proven with the extra heavy rods of the AdaptX – a new machine on the market with unparalleled capabilities, manufactured by OptionX Group company Bournedrill. The system uses high pressure air hammers in sequence – exhausting cuttings through a custom removal system – and is ideal for very high strength rock,” Mr Harrison said. 

“The new system also has environmental and workplace health and safety benefits, enabling small to medium-size pipe diameters to be installed in hard rock faster, with a significant reduction in spoil removal and truck movements compared to open cut methods.”