African Mining April 2020 | Page 14

 MINE EXCURSION  MINE EXCURSION #AMequipmenthire We will be supplying our readers in the mining, quarrying and civil construction sectors with leading information and insights on products and related services pertaining to mining equipment and hire. DON’T MISS OUT MARKETING OPPORTUNITIES: Get seen by the mining, quarry and civil construction sectors. Chantalle Schilling +27 (0) 73 243 0525 [email protected] This supplement will be distributed to all African Mining readership (5 803) as well as digitally to our other readership in the construction and civil space (13 111). EDITORIAL CONTRIBUTIONS: Leon Louw +27 11 (0) 579 4940 [email protected] The supplement will be featured in the May issue of African Mining. 12  African Mining April 2020 The integrity of the steel in the vertical shaft is scanned with two underwater cameras and the images are relayed on a screen 299m below surface. runoff and precipitation is the main cause of flooding and not groundwater, and when Anglovaal built the shaft, they did it properly and way above required specifications. “The water is not our main challenge. At the moment, we are running pilot water treatment trials, pumping 5 cubic metres of water per hour. At full scale we intend to be pumping out about 1 000 cubic metres of water per hour. In total, we need to get rid of about 8.5 million cubic metres that has accumulated in the shaft over the past 30 years or so,” says Shamu, standing on the solid platform erected in the shaft by the reconnaissance team contracted by PCDS, the engineering company appointed to test the integrity of the vertical shaft. The platform is at 299m below surface just above the water level. Next to the platform there is a big screen on which close-up images of the steel structure and shaft are relayed via two underground cameras. The camera’s stop every four and a half metres to get detailed images. These images are scanned, inch by inch, by a team of structural engineers and steel construction and shaft sinking specialist. Any anomalies in terms of pattern, colour, water movement, or cracks are closely monitored and scrutinised again and again, to look for signs of potential failure. “We had to use divers to get the cameras and other equipment into the water so that we could test the main steel members of the shaft, which is really our primary concern. The lighter steel components will be removed and replaced,” explains Shamu. At first glance the steel frame looks fraught, but 12  African Mining April 2020 www. africanmining.co.za