TRENCHLESS TECHNOLOGY
disruptive construction activities – e.g. open-cut trenching across a major traffic intersection or business node. Classic TT examples for new installations and upgrades include horizontal directional drilling, pipe jacking, micro tunnelling, pipe bursting, CIPP and slip lining. Running in parallel are invaluable asset management tools for critical aspects like in situ pipeline inspection (water and sewer) and leak detection. As with choosing any construction technology, it’s about economies of scale. That’s also interdependent on having the best information. Has the Covid-19 cost-cutting environment made TT too expensive? No, this is not the case, since TT has been proven to be faster and more cost-efficient in its purpose-designed application – i.e. urban environments and complex infrastructure projects like underground pipeline river crossings. But before any technology debate should be engaged, we first need to answer a universal question: can we
afford to carry on with a ‘business as usual’ approach? The answer is an overwhelming no. If we do, then we are unlikely to meet our National Development Plan (NDP) 2030 targets. The advent of Covid-19 is the reset button worldwide for a fresh approach to key issues like smart city evolution and sustainable habitation in general. Historically, TT has always been part of the response, but now it’s an indispensable part of the solution. Do municipalities have a clear understanding of where TT can be employed? Early adopters and TT pioneers like the City of Cape Town have certainly proven the benefits on a wide range of water and sewer pipeline projects. Their leadership approach has subsequently filtered through to other Western Cape municipalities like Drakenstein, Overstrand and Stellenbosch. However, across the board, we generally find municipalities have not adopted TT because it’s not well defined in their existing toolbox. Many
Before CIPP refurbishment on a section of the Blackmac Sewer
After installation of the CIPP liner
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municipalities and public sector entities also still tend to view TT as a single methodology. From SASTT’s perspective, we need to ensure that there is a clear understanding that TT is multifaceted and scalable. TT is also an indispensable way for municipalities and utilities to obtain accurate infrastructure condition assessment reports using CCTV cameras to inspect pipeline networks. When municipalities understand the scale of the problem, they have a plan of action. Otherwise, they’re severely constrained. Can you prove the business case for TT versus open-cut trenching? Statistically, it’s been proved that TT is around 30% more efficient compared to open-cut trenching in urban environments worldwide. Open-cut projects, for example, are yellow metal intensive, with their associated diesel fuel burn costs. They also have higher costs associated with major earthworks and the re-establishment of infrastructure like asphalt overlays. In contrast, TT is greener and cleaner. Of course, there will always be scenarios where open-cut trenching is more cost-effective. Examples include rural areas, greenfield developments where there’s no existing infrastructure in place, and pipeline replacement projects where there is too much existing congestion in terms of old networks. Another example would be where the displacement caused by an upgraded pipeline is too large, ruling out a TT pipe bursting approach, say where the required pipeline size of the new installation is more than 1.5 times the diameter of the existing pipeline. Is there space for SMMEs to enter the TT market? This is one of SASTT’s major objectives for 2021 and beyond. We are committed to creating a platform where we can attract new entrants, especially SMMEs. However, it’s a ‘chicken and egg’ scenario, since construction sector recovery and growth depend on how soon government can ramp up its infrastructure investments. Our role as SASTT is to provide SMMEs with the requisite knowledge.
