Modern Mining September 2019

methods and equipment for vertical shaft sinking and horizontal development that have essentially remained unchanged for decades. “There has to be a better way of doing things and we believe our new machines will provide the answer.” The MTB is an adaptation of the Tunnel Boring Machines (TBMs) used in civil engineering to the specialised demands of hard rock underground mining. “Conventional TBMs have been trialled in mines in the past but generally have not impressed,” said Pretorius. “We have come up with something radically different – it is small, with a weight of 300 tonnes and a length of just 31 m in its 5,5 m diameter configuration, has a modular design, which makes it relatively easy to disassemble and move, can oper- ate on a 12 deg incline or decline, and has a turning radius of only 30 m. We think it has the potential to be a real game changer.” To initiate cutting, the MTB requires a rounded profile side wall to grip and thrust the machine for- ward. For this reason, a starting frame is assembled in advance of the next heading to be tunnelled. Once the backup of the MTB has advanced through the starting frame, it can easily be disassembled and moved to the next location where a new heading will begin – this process will then be repeated. For breakaways, the MTB relies on a starting chamber that will be excavated and made safe by cyclical conventional mechanised drilling, blasting, scaling, loading, supporting and hauling equipment. The MTB is already in South Africa and has recently been deployed at a platinum mine. Master Drilling will be reporting in more detail on its per- formance once sufficient operating experience has been gained. Turning to the Shaft Boring System (SBS), Pretorius said the ‘front-end’ had recently arrived in

JSE since 2012 and in 2018 recorded revenues of US$138,7 million and an operating profit of US$23,6 million. Despite generally difficult conditions in global mining, it increased its revenue year on year for the six months ended 30 June 2019 by 3,8 % to US$70 million. The company’s order book remains strong at US$198,6 million and the new business pipeline solid at US$297,1 million. While raiseboring is likely to remain the backbone of Master Drilling’s operations for years to come, the company sees its investment in the MTB and the SBS as critical to its future – and indeed critical to the future of the mining industry which desperately needs new technology to make access to under- ground orebodies safer and more economic. As Danie Pretorius, CEO of Master Drilling, recently told Modern Mining , the mining indus- try is currently using

The ‘front end’ of the Blind Shaft Boring System established on site at Fochville.

“There has to be a better way of doing things and we believe our new machines will provide the answer.”

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September 2019  MODERN MINING  39