A section of the pipeline near Koorarawalyee was recently upgraded because additional water pressure caused by the construction of several more-efficient pumping stations over the past decade was proving troublesome for the original pipe.The original 700mm steel “locking bar” pipe – so named because of its design, which included two pipe halves and two side locking bars, allowing compact stowage on board cargo ships from England – had no corrosion protection at all. It had to be assembled onsite and anti-corrosion technology was not available to the construction teams in those days.The pipe was generally, initially, installed below ground; however, because of corrosion issues it was later dug up and installed above ground as it is today.The new Tyco “Sintakote” steel pipe has a polyethylene coating, which is extremely corrosion resistant and allows the pipe to be buried. The pipe also has cement mortar lining on the inside. In addition, individual rubber ring jointed pipes are electrically connected with earthing straps and allow for the whole buried pipeline section to be cathodically protected against corrosion. DM Civil was awarded the main conduit replacement contract by project alliance partners Pipelines and Pump Station Partnership (SKM-Transfield Services-Water Corporation) for the client, WA Water Corporation, early in 2008. The construction commenced in June and pipe laying was completed by early August.DM Civil project director Bruce Shaw said the pipeline job was more significant than many others.“Not every day do we get to work on improving something that’s very famous and over 100 years old,” he said. “In fact I’d go further and say the Goldfields pipeline is the most famous civil engineering feat in the entire history of WA.“We considered it quite a privilege to be entrusted with such a historically important job. Our relationship with the Water Corporation goes back many, many years and we really feel honoured to be appointed to this project.”The Goldfields pipeline opened in 1903 and has been continuously upgraded to maintain its status as a world-class water supply scheme. Design and construction of the pipeline was largely overseen by WA’s engineer-in-chief, CY O’Connor, who was also responsible for building Fremantle Harbour. About 300km of O’Connor’s original 552km pipeline remains. Over the years pumping stations en route have increased from eight to 19. Water storage locations en route have also increased from nine to 13. The original steam-powered pump stations have been replaced with electric-powered pumping stations and supplemented with booster stations.A sophisticated telemetry system has been installed at Cunderdin enabling pumps, valves and storage systems for the scheme to be remotely controlled, which helps minimise electrical and operation costs.Supply capacity has increased by well over 8 billion litres per year in the 105 years since the pipeline first delivered its precious contents to Coolgardie and Kalgoorlie-Boulder.Shaw believes there could be further work such as this for the pipeline in the future as the Goldfields water supply demand increases.“From our involvement in the work on this project everyone at DM Civil has developed enormous respect for the pioneering engineers and workers designing and installing the original main conduit,” he said.“They did not have our current knowledge, technology or equipment and so it makes what they achieved so many years ago a world-class engineering feat.”
