Australia

Not only is trenchless works typically more time efficient than open cut alternatives, meaning that machinery is operated for shorter periods, but traffic fuel consumption is lowered by trenchless methods.

By avoiding traffic disruptions, trenchless projects prevent the delays and detours associated with conventional underground infrastructure projects. This lowers the amount of petrol consumed, and subsequently reduces carbon emissions.

In addition, according to a study conducted for the North American Society for Trenchless Technology (NASTT) by the University of Waterloo, located in Ontario, Canada, it found that trenchless job sites produce fewer emissions.

They require minimal construction machinery and equipment as there is no need for excavation, compaction, backfilling and re-paving, dramatically reducing fuel consumption.

With the industry focused on preserving the environment and reducing emissions, the ASTT created a Carbon Calculator to promote innovation in the trenchless technology sector.

The purpose of the ASTT is to advance the science and practice of trenchless technology for the public benefit, while promoting education, training, study and research and practice for the public benefit and to publish the useful results of the same.

With this in mind, paralleled with the global goal of reducing carbon emissions, the ASTT formed a Special Interest Group (SIG) of leading industry professionals to create a solution that supports the mitigation of climate change impacts.

ASTT Councillor Matthew Boyle says the ASTT embarked to create a SIG to look at the impact trenchless technology has in reduction carbon generation in construction projects. “The SIG’s purpose was to provide members with access to a Carbon Calculator to quantify, and therefore promote, trenchless technology as a lower carbon emissions alternative to Excavate and Lay,” he says.

“The primary focus of the SIG was to provide members a tool to compare greenhouse gas emissions using comparative approaches in the capital delivery of services.”

As a result, the SIG approached the market for the development of the calculator and selected the Moata Carbon Portal from Mott MacDonald in August 2020.

At the time of release, it was the first carbon calculator capable of measuring the capital and operational carbon footprints of building information modelling (BIM) designed assets.

Boyle says following Mott MacDonald agreeing to be on board with the ASTT, the SIG moved into trial phase where asset owners were selected to use to the tools in their businesses for best use practices in Australia.

However, it was here where the process stalled and the use of the calculator in the trial was limited, little feedback was submitted, and the pandemic hitting Australia.

Boyle says the SIG has currently been suspended until further legislation and member support.

“We went with Mott McDonald because in New Zealand there is a legislative requirement to monitor carbon emissions, but until there is something in place like this in Australia, the SIG has come to a halt.”

In December 2021 the Australian Government released the June 2021 quarterly update of Australia’s National Greenhouse Gas Inventory.

Australia’s greenhouse gas emissions fell by 2.1 per cent in the year to June 2021, and have fallen by 20.4 per cent since 2005

Boyle says he sees the awareness of carbon emissions driving the trenchless community to look deeply into its supply chain to innovate and come up with new techniques and products to drive zero emissions further into the future.

“I see the specification of low emitting trenchless technology by asset owners and government organisations to be the standard across Australia and New Zealand,” he says. “I believe this will be backed up by legislation and the trenchless community will be well placed to help deliver on a low carbon future.”

With the trenchless community already doing its part to reduce emissions, Boyle says the rehabilitation process for overall asset installation can be measured, quantified, and improved into the future.

This is where the Carbon Calculator could demonstrate how the use of trenchless technology can reduce project carbon emissions.

“This is great evidence for asset owner members, contractor members and supplier members. It could also be used to see what part of the process emits more carbon, allowing innovation to occur to effect overall emission reduction,” Boyle says.

The ASTT says its Carbon Calculator is not to be relied on to make commercial decisions nor is it a tool that will accurately define Capital Carbon Baselines, noting that there is no specific, quantified carbon goal that the calculator aims to reach.

Rather, the tool will be used to promote best practices across the industry.

The three steps the calculator aims to take is:

1. Reduction – reduce the carbon impact of infrastructure.

2. Behaviours – improve the behaviours of designers, constructors, and entire supply chains to reduce infrastructure carbon.

3. Union – create a common way of working to calculate carbon reductions across the industry, setting the narrative.

Boyle says with the ASTT’s overall goal being to advance the science and practice of trenchless technology for the public benefit and to promote education, training, study and research and practice for the public benefit, it is hoped the calculator will be used on individual projects and tested across various areas, with the onus on contractors and client organisations to use the tool and consider their own impacts.

“With this as our goal, we will support all measures that our members are taking to reduce emissions and promote to educate the greater community into the advancements and benefits of trenchless technology,” he says.

Located in regional Victoria, local utility GWM Water discovered that one of the network drains had been badly damaged by an external source. The drain had a diameter of 375 mm, and damage was only the top third of the pipe.

The repair proposal offered up several different options with varying cost and different degrees of difficulty accompanying each.

It was important to work through the different scenarios with the client and look at what was going to deliver the best value for money, cause the least disruption, and generate the greatest long-term outcome.

There was the option of setting up a bypass line over a train line, which instinctively brings with it a complete set of complications that must be worked through, as well as the planning process and time restraints.

By using this methodology, there were options to restore the line by either cutting it out and replacing it in its entirety or installing a new top section of host pipe and then patching the area using a bladder in the network.

The second option of patching also brought its own challenges around formation of the patch, managing the host pipe repair under inflation, and the team would still have the bypass line to work through.

The suggestion was made to rebuild the line using Smart Lock. This was something the utility had not seen or used before on its network. Smart Locks can be installed to rebuild the line under flow, in this case removing the requirement of bypassing and managing the bypass across a train line.

Once GWM Water saw the way that Smart Lock works, the client realised this was the best option on this desperately needed repair. GWM Water was impressed by how the stainless-steel banded together with the silicate impregnated fibreglass to restore the pipe’s shape and build structural integrity back into the line.

Work commenced and the damaged pipe was rebuilt using 5 Smart Locks, each locking into the previous one by managing the pressure used to blow out the packer. Once all the Smart Locks were joined together under live flow, CCTV footage of the drainage system was taken, and the outcome was demonstrated to be successful. The section of the pipe was covered in concrete to alleviate the same mistake happening again.

The finished product came up extremely well with little interference to the network and definitely a great saving to the client.

How it works

The Smart Lock is an innovative solution that is quick and easy, completed in three simple stages: load, lock and leave. By wrapping the stainless-steel sleeve with fibreglass and silicate resin and sending the packer down the pipe and into position, the Smart Lock solution is loaded before being locked into place by the innovative ratchet system to complete the repair.

With an average installation time of only 20 minutes, the installation team can leave to get to the next job as the resin impregnated fibreglass matting is left to cure behind the stainless-steel sleeve.

Smart Lock is ideal for localised defects such as cracks and holes, root infestation, water infiltration, displaced joints and redundant lateral connections. All can be repaired by installing a Smart Lock directly at the location. The solution provides a cost-effective alternative to excavation, relining or pipe replacement and is a permanent and structural repair.

Established in 2013, Jelmac is a proven trenchless technology leader in Victoria, specialising in horizontal directional drilling (HDD). Based in Melbourne, the company works across all major utility sectors and essential services, as well as local builds and small-scale projects.

Over the past few years a significant portion of Jelmac’s resources have been focused on the considerable upgrade to the rail network in suburban Melbourne. The company prides itself on it’s experienced and reliable team, which relishes tackling challenging briefs, no matter how big, small, unique, or complex, working hand in hand with it’s clients to ensure it does everything it can to get the job done, no matter how complex or unique, with full transparency along the way.

The GRUNDODRILL 28N is the seventh HDD rig in Jelmac’s fleet, featuring drills of varying sizes and capabilities. The diverse machines give the company the flexibility to use a ‘horses for courses’ approach to jobs, depending on variables such as the size of the jobsite, geology, and the length and diameter of the installations.

One of the key factors which made the machine so attractive to Jelmac was the machine’s immense power, with 100 per cent of the rig’s 224 kW of power directed towards drilling operations. According to TRACO, this aspect of the machine’s design and performance is unique in the up to 300 kN pulling force power class.

The extra power also supports an advanced mud system, supplying up to 650 l per minute of bentonite, facilitating increased productivity and faster drilling, as well as opening up the possibility for contractors, like Jelmac, to undertake larger and longer bores.

In addition to this power and the effect it has on the functions of the GRUNDODRILL 28N, the drill also features automated and comfort benefitting the end user. Two multi-function joysticks are used for all functions in bore and drive mode and can be switched between manual, semi-automatic and fully-automatic modes.

In the airconditioned cabin is a panel PC with touchscreen and internet connection, making operations straight forward for the end user. Custom ergonomics have also been considered, with an extra-large and comfortable seat, with air suspension and automatic weight adjustment.

Trenchless Australasia spoke to Jelmac Managing Director Brad Boote on the site of a rail project in southeast Melbourne, where the GRUNDODRILL 28N recently completed a 370 m long bore with a diameter of 450 mm in siltstone which he believes to be the biggest installation in the company’s history.

“This installation we’re working on here is probably the biggest bore we’ve ever done, lengthwise at the very least,” he says.

“Since taking delivery of the machine in August 2021, we’ve seen this machine stack up against similar rigs we’ve used in the past with a few key advantages.

“The number one being it’s fluid delivery ability – there’s a lot more litres per minute that we can pump down the borehole which helps us with larger diameter bores, like we’ve just done here,” he says.

Mr Boote says another advantage of the GRUNDODRILL 28N is it’s capacity to house almost 300 m of drill rods, meaning on this particular installation his team only had to load a few rods at the very end to get reach the final length of the installation.

“A lot of machines only have 180 m of rods onboard, so this would’ve been a big job for a machine like that. The other thing is, at only 3 m, these rods are easier to handle; changing them out is a one person job, whereas with other machines it would’ve required loading one rod at a time using an excavator taking up two people.

“A lot of our work is generally under 250 m, so the 28N fits the purpose really well with the diameters that we do, the fluid delivery and the rods – so those three aspects are really important for us.

Mr Boote says because a lot of Jelmac’s work is on confined job sites, the design of the machine means it’s suitable for most of the projects they work on. Beyond the technical specs and features of the machine, the client-supplier relationship is also important to the company.

“That is very important to us and is another reason why we decided to work with TRACTO,” says Mr Boote.

“Investing in this sort of equipment is always a big decision and a massive commitment. We need to know that we can rely on TRACTO for support, training, sales, servicing and spare parts to ensure the machine is in operation when we need it to be, maintaining the efficiency and the standard of work that our partners have come to expect from Jelmac.”

“So far we’re really happy with the decision. I hadn’t had a chance to sit on the machine while it was operating on a job until last week and it was a dream.”

For more information visit TRACTO-TECHNIK’s website.