When working on a project requiring the trenchless installation of pipelines, close collaboration between subcontractors, contractors and engineers can result in project efficiencies, cost savings and a better long-term final outcome. Here, Stuart Harrison, Managing Director at Edge Underground, discusses the benefits of close collaboration not only for the project, but also for the wider trenchless industry as a whole.
According to Mr Harrison, while there are always site specific issues that cannot be predicted and will need to be addressed as they arise when undertaking a trenchless project, there are a number of predominant issues that tend to be consistent across all sites, which can be addressed prior to the installation starting.
“The crew at Edge Underground has decades of experience working on trenchless projects across Australia, so we know and understand the common issues that are present on all sites. So we try to speak to contractors in advance of works starting to discuss these problems and what can be done to mitigate them,” Mr Harrison said.
“We’re also always happy to speak to the engineer designing the project.
“Most importantly, if we’re contacted for a quote before a project or at any point before a project commences, after we’ve spoken to the engineer or contractor, or seen the site and we think that what we’re offering isn’t the best option for the job, we’re always happy to let them know there is a better alternative for the job.”
The importance of choosing the right method
Mr Harrison said that the company understands that the term trenchless is broad and encompasses a number of different methods that all have the same goal: to put pipe in the ground without the need to excavate.
“Within the trenchless industry, you can speak to any professional and all of them will be able to tell you that each of those different methods have strengths and limitations,” Mr Harrison said.
“If you use the wrong method for a pipeline installation it can be disappointing financially and produce a disappointing result.”
Mr Harrison said an example of this was a project Edge Underground was called in to take over from another contractor involving the installation of an 88mm, 315 HDPE sewer pipe on-grade at a depth of around 4.5m at a school.
Before taking over the project, Edge had previously spoken to the client about the price for a microtunnelling solution, as well as the possible risks associated with the job. However, initially, a cheaper contractor offering a directional drilling solution was chosen. But once drilling started, the contractor encountered problems achieving grade.
Despite the directional drill not achieving the desired accuracy, the contractor still tried to ream and install the pipe. But problems arose when it was discovered that the pipe was going in on all the wrong angles.
“When it was realised there was a problem, we were called in to take over. However, there was a bunch of extra work we needed to complete at the same time because the ground had been left in a poor condition from the directional drilling,” Mr Harrison said.
“We were told that the ground had been treated, that it had been filled with grout and that we wouldn’t have any problems. But when we went in and started doing our pilot shot, we established that they hadn’t been successful in grouting.
“There were massive voids left in the ground which could have caused problems, but because we use the AXIS laser guided boring system, we can go to a point, trip out, and grout as needed, all without needing to excavate.
“As soon as we were able to get the ground into a semi-reasonable condition, we were able to install the pipeline.
“Everyone was very happy with the end result. There was time in the middle that cost everyone money, which was due to the lack of transparency and the initial choice to go with the cheapest option. Directional drilling just can’t achieve the same level of accuracy as microtunnelling, so if more open consultation had occurred at the start, maybe time and money could’ve been saved.”
Close collaboration good for the industry
Mr Harrison said when a design goes out to tender without prior consultation, pipeline installation contractors often have to bid a conforming tender, but the hope is that the non-conforming bid comes up.
“Contractors in general are pretty ingenious, they’re always looking for a more efficient way of doing a job. But by nature, engineers and designers are risk averse. So they will go with something that they know, and they feel that they can trust,” Mr Harrison said.
“In the middle the roads meet. We hope that we can have a logical conversation between the contractors and the designers so we can provide something that not only achieves all the outcomes that are desired, but that it’s also done in a way that is at the most cost-effective and has least risk.
“We both get the benefit of that.”
Mr Harrison said close collaboration between trenchless contractors and engineers will help increase the trust and confidence needed in the trenchless industry for more engineers to recommend it for projects, helping to grow the industry as a whole.
“We all have to do projects sometimes knowing full well that there is a better way of doing it. Now in saying that, we also have to be mindful that sometimes we’re not aware of all the variables that they’re taking into consideration,” Mr Harrison said.
“Maybe there’s future aspects that they need to consider. Different pipelines have different requirements and materials. But from doing this sort of thing for a long time, there is often a more streamlined approach that can tick all the boxes. It is really a matter of just having that open, honest conversation. Getting more successful outcomes.
“So wherever we can get more industry professionals assisting to get designs right, relative to the desired outcome, I think we help our industry grow because the people that we’re working with gain confidence that they’re going to prescribe something that will be successful.
“I think everyone in the industry has the burden to assist that process, and help clients come to some sort of a great outcome from our advice, from what we’re putting in.”