Longwall operations at North Goonyella in central Queensland have been stopped since December 12 after two unanticipated geological faults were encountered simultaneously. One of the faults runs across the corner of the block being cut while the second is a low angle reverse fault about 6m up in the roof.

The problem started with a minor fall in the tailgate. Operations were able to resume but when the shearer went into the maingate area roof bolts began weighting up suddenly and the gate roof then fell onto the crusher and stage-loader.

North Goonyella general manager Brian Nicholls said there were no indications of the problem before it occurred, but added that it was a valuable learning experience for mine management.

Operations are currently working through the fall. Additional roof support has been installed, including PUR, extra cable bolts and RSJ steel sets. The cavity in front of the chocks will be filled with durafoam to provide additional support. Electric and hydraulic power has been maintained on the face to allow other maintenance work to be done while the fall is being recovered.

Management anticipates the longwall being back in production by the middle of January.