Modern Mining February 2016

TECHNOLOGY

New shaft boring system could be a ‘game changer’ for mining

established technologies, it is revolutionary in the sense that – unlike current mechanised raise boring services used to bore shafts – it requires no bottom access underground. Elaborating on the timeline to bring the BSBS to market, Germishuys said the concep- tual stage of the project was now complete and the initial design in place. Master Drilling was now in the process of producing the first unit, he said, and had pre-qualified manufacturers and issued enquiry documents. The award of a contract was expected in Q2 2016, he said. The manufacturing phase would extend through from Q3 2016 to Q4 2017, with the machine – which will weigh several hundred tons – being ready for service by the first quarter of 2018. Although the BSBS has been developed in- house by Master Drilling, there has been some input from WorleyParsons, the EPCM contract- ing and mining consultancy group, which has ‘double checked’ the initial design and assessed the time and cost savings the system can deliver over conventional blind shaft sinking. The IP around the system is owned by Master Drilling. The first rig is being produced ‘at risk’ by Master Drilling and will involve the company in a substantial investment. The company believes that the money will be well spent, as it will give it a competitive advantage in the mar- ket. Shaft sinking times will be cut by up to half, resulting in a dramatic impact on project NPVs and IRRs – and also enabling previously mar- ginal projects to be profitably developed. The

Master Drilling, a JSE-listed drilling solutions provider which ranks as the world’s largest raise boring contractor, used this year’s Mining Indaba as the platform to unveil its new Blind Shaft Boring System (BSBS), an innovative com- bination of established technologies with the potential to revolutionise the field of shaft sinking.

T he BSBS was introduced at the Mining Indaba by Louis Germi- shuys, COO – Shaft Development at Master Drilling, who said the system offered numerous advan- tages over conventional sinking methods in- cluding vastly enhanced safety and an advance rate of up to 7 m per day – roughly twice what is normally achieved with traditional meth- ods – with a total crew of just 40 workers. He added that the BSBS, which can be deployed on both greenfield and brownfield projects, ob- viated the need for pre-sinking operations and also eliminated the need for blasting. The system can be used to create shafts of between 10 and 14 m in diameter in hard rock (of up to 300 MPa compressive strength) to depths of up to 2 000 m and is a combination of proven best practice in slurry drilling, rock cut- ting (TBM) technology and hoisting systems. It offers minimum exposure to the unlined shaft sidewall with the shaft lining operation (using precast concrete segments) following close behind the boring of the shaft. While it uses

Pictured at the Mining Indaba with a model of the BSBS are (from left) Danie Pretorius, founder and CEO of Master Drilling; Louis Germishuys, COO – Shaft Development, Master Drilling; Murray Macnab, Global Director Mining and Mine Development, and Steve Gouws, National Discipline Manager Mining Engineering, both of WorleyParsons; and Koos Jordaan, Technical Director, Master Drilling (photo: Arthur Tassell).

28  MODERN MINING  February 2016