TRENCHLESS TECHNOLOGY
Sustaining the value of underground assets Left unchecked, intensive urbanisation places increasing pressure on existing and ageing water and sewer pipeline infrastructure. Responding to the challenge requires an innovative approach that also builds construction capacity, particularly for SMMEs. Alastair Currie speaks to Neil van Rooyen, vice-president, Southern African Society for Trenchless Technology (SASTT), about trenchless solutions. What are SASTT’s primary objectives in 2021? NvR Communicating the advantages of trenchless technology (TT) has always been our primary mandate. Aside from ongoing education and training, our overall objective is to establish an enabling TT framework that serves as the benchmark for informed decisions across the public and private sector. This includes ensuring the appropriate standards and specifications are in place from a contracting and procurement perspective. At present, specifications have been written for slip lining of pipelines, pipe bursting and horizontal directional drilling, and we’re busy finalising a document for cured-in-place pipe (CIPP) lining specifications. We’ve also recently completed a draft for CCTV specifications. Overall, we must ensure that there is a unified understanding and appreciation of the benefits of TT as a holistic solution, with a Installation of liner in Blackmac Sewer
major emphasis on promoting those ideally suited for South African conditions and our infrastructure priorities.
What’s the significance of being part of the broader International Society for Trenchless Technology? It’s very important because it enables us to learn and apply international best practices. In developed countries, the focus is on efficiencies, so they readily embrace TT because it makes financial sense. Commercial activities cannot be constrained because of 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
Cape Flats 3 Bulk Sewer – Phase 2: positioning the jacking frame within the jacking shaft (Photo credit: Terry February)
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 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
