Developments in controlling the roof in South African coal mines — a smarter approach by

The use of rockbolting as roof support is an essential element of high productivity mechanized coal mining. In South Africa, the USA and Australia, rockbolting has been used in coal mine room-and-pillar operations for many years, and the productivity of this mining system continues to increase with advances in equipment design and capacity. More recently, rockbolting has been applied to the support of gateroads for longwall retreat systems, allowing the productive potential of modern heavy duty longwall equipment to be realized. In contrast the general situation in the remaining European coalfields is one of limited technical change, with longwall retreat mining widely practised, but with steel arch gateroad support, and consequently with relatively poor productivity. One reason for this difference lies in the perception that in European coal mining conditions, with large depths of working, weaker rocks and interaction from previous workings, rockbolting would be unsafe. However rockbolting has been successfully applied in exactly these conditions in UK coal mines in the last ten years with unprecedented levels of safety (Arthur et al.1). The introduction of rockbolting was the result of a comprehensive research and development programme undertaken by British Coal prior to industry privatization in 1994 and part funded by the European Coal and Steel Community. This work resulted in a fundamental advance in the science of rockbolting, which allowed its successful application in these difficult conditions. Four key steps in applying rockbolting in these conditions were identified: