Case Study Management of Outburst Risk at Tahmoor Colliery

Tahmoor Colliery mines the Bulli Seam at a depth of 400-440m and has had to manage the risk of outbursts since it commenced production in the early 1980’s. Of necessity, it has been at the forefront of the development of systems to reduce outburst risks and has made many significant contributions to the industry in this regard. In the 1980’s, the general strategy for addressing these risks was that outbursts were “inevitable” and so most effort went into protection against their consequences. By the 1990’s, this approach was no longer acceptable and there was a major redirection of effort towards the prevention of outbursts. This effort has been highly successful and there has not been an outburst at Tahmoor since 1992, when predrainage of development commenced. Prior to 1992, outbursts were occurring at an average rate of about 10 per year.