Case study

On 15 April 2014, a pressure burst in the Greta Seam at the Austar Coal Mine at Paxton, near Cessnock in NSW, claimed the lives of two mine workers.

A pressure burst is a dynamic energy release in the surrounding rock mass, resulting in a rock/coal failure, ejecting material into the mine roadway at high velocity.

On the day, seven mine workers were located about 555 metres below the surface and 10 kilometres from the mine’s entry point. The men were working on a development roadway (gate road) for a future longwall panel. They were using a continuous miner and shuttle car to remove material. They were also securing the roof and sidewalls (rib) with steel bolts and mesh.

A large section of the left rib, which was supported with steel bolts and mesh, moved sideways and collapsed into the roadway. The pressure burst was of such a magnitude and volume that it rendered the installed rib support ineffective. Two of the seven workers were located at the point where the rib burst occurred and were buried by the rockfall.

Co-workers attempted to rescue the men, but the area was deemed unstable. Their bodies were recovered 2 days later.

This incident claimed the lives of two miners: James Mitchell (49) and Phillip Grant (35)