As our urban centres continue to grow and our demand for resources needs to be met, I expect there will be continued growth for the HDD industry as long as we ensure clients our methods and practices are well engineered and reliable. For example, the Australian market has been slow to take advantage of new technology such as gyro surveying, which is widely used in other countries. One recent application demonstrates its value and the need for accurate and independent confirmation of pipeline as-builts installed by HDD. A civil engineering contractor was engaged to construct a major road underpass and was in the process of drilling in the concrete piles when they severed a 300mm diameter conduit containing a 132kVA cable. According to the as-built supplied they were more than two metres away from the three HDDs. We mobilised the next day and were able to survey the two remaining conduits, which contained the other phases. We confirmed the position of the two remaining conduits to +/-150mm along the entire length of the crossing therefore allowing the works to confidently proceed.
In this case, they were lucky no-one was hurt and just had a major power outage to deal with. As most pipe bundles are installed with a spare, I would like to see all HDD crossings re-surveyed with the gyro tool to ensure pipeline owners and service suppliers have accurate and reliable as-builts. I think this will simply become more and more critical as HDD installed infrastructure continues to grow with population density.
Secondly I feel that we, as an industry, need to increase the quality, reliability and performance of HDD services in Australia. Our industry continues to expand, at all levels, and there should be a means to standardise performance and ensure product delivery. At the moment there are no real codes of practice that exist that are applicable to current practices and capabilities of the market. Often foreign or out dated references are used in contract documents; but these are rarely applied or used in earnest.
To give pipeline owners, engineers and contractors a valid and recognised guideline would greatly enhance industry performance, reduce construction risk and ensure best practices are employed. It would help put Australian construction practices forefront on the world stage, and would provide the fabric for the development of HDD QA/QC. Every other part of pipeline construction is regulated but often the most challenging part of the works, the HDD, is left without independent inspection and verification. Stockton Drilling Services is hoping to help facilitate the pipeline industry and trenchless industry in working together to develop a code of practice/guidance note for the planning and execution of HDD projects in Australia.
About Charles Stockton
UK-born Charles Stockton has been a part of the HDD sector in Australasia since 2003. He is the Managing Director of Stockton Drilling Services, a leading engineering consultancy specialising in HDD and other trenchless pipeline installation methods.