Water & Wastewater Treatment Magazine
Issue link: https://fhpublishing.uberflip.com/i/1178180
Getting to the heart of sewer repair Wessex Water's award-winning Re-Rounder, inspired by heart surgery techniques, helps get deformed sewer networks back into shape By Jamie Hailstone www.wwtonline.co.uk | WWT | NOVEMBER 2019 | 27 The Knowledge Innovation Zone cular surgery and are 1.2-mil- limetres in thickness. "We wanted an efficient and structurally sound design, with the lowest thickness, and without any ratchets which would be an impediment to flow," Wessex Water's sewer rehabilitation programme manager, Julian Britton, says. "We also wished to avoid cross-sectional area loss." The stents are purposely manufactured with a shal- low 'V' in the full metal axial sections to 'bite' into the host pipe. This is to ensure the stent does not move when workers T hey say inspiration can come from anywhere but, in the case of Wes- sex Water's multi-awarding sewer repair robot, it came from human heart surgery. The Re-Rounder device, which recently won a hat trick of awards from the United Kingdom Society for Trench- less Technology (UKSTT), has been designed and built to bring 150-millimetre diameter sewer pipes, which have suf- fered up to 25 per cent defor- mation, back to their original shape prior to CIPP lining. The robot picked up the UKSTT's Innovative Product jet clean the sewer repair prior to lining. The machine can be used with rigid clay or concrete sewer pipes, as well as pitch fibre pipes. Wessex Water owns almost 20,000 kilometres of 150-mil- limetre diameter wide sewers. Pitch fibre pipes are also known to contain asbestos, which can raise additional problems in terms of excavat- ing. "We completed proof of concept, and then undertook a worldwide patent search to establish its uniqueness and innovation," Britton adds. "We and Renovation Water and Wastewater Sector prizes, along with the overall Project of the Year award. It comprises a robot that 're-rounds' the pipe by leaving in place a metal stent, much like the ones now used by heart surgeons. The stents are made from stainless steel and are laser cut to allow expansion of the stent, without the need for a traditional "metal-on-metal" rachet system used by the pneumatic systems on the market. The designs of the stents were borrowed from cardiovas- SEWER NETWORKS