The BHP Billiton Illawarra Coal mine in NSW completed the hole-in of the longwall face using the shearer to drive into the recovery road on July 18. The hole-in will allow the mine to eliminate the need to expose operators during the usual "bolt up" phase leading up to the longwall recovery. It will also allow the mine to relocate the longwall at least seven days earlier than using the conventional "bolt-up" method.

The potential risks with the operation were carefully managed and planned for over six months in advance. A dedicated team made up of mine site personnel and staff from geotechnical consultants Strata Engineering was set up specifically for the project. Strata Engineering provided round the clock monitoring and analysis of the pre-driven roadway for the four days prior to hole-in. Some additional megabolts were used to supplement the roof along with fibrecrete cribs that were later cut out by the shearer.

“The operation proceeded in accordance with the meticulously prepared plans despite a minor hiccup when, with only 4 metres to go, overbreak across the mid-face area required the intervention of longwall coordinator Darren Lee and senior mining engineer Steve Bow in the early hours of Sunday morning,” said Strata Engineering consultant Tim Watson.

It has been some years since this method of face recovery has been used and given its success it is likely that other mines will consider the use of similar methods for face recovery.