The Moranbah North mine is currently negotiating a major 4m fault, which has slowed longwall production to a trickle.
The fault was reportedly anticipated but because of the presence of sandstone in the panel, particularly on the outbye side of the fault, progress has slowed.
ILN understands that the sandstone is causing some problems with roof control, with uncertainty about how the supports will cope.
The Bowen Basin mine was recently sold as part of the Shell Coal assets to Anglo.