Longwall face widths should continue to average 270m and while extending this to 300m is possible, BHP says some of the “business fundamentals” will need to improve before the additional capital expenditure can be justified.

“Going to 300m will cost an additional $250,000 for each support,” Seymour said. “Every extra metre costs $160,000.”

In the medium term Seymour said one of the mine's priorities will be looking at cost reduction, targeting “unnecessary activities”. Over the next three months management will conduct an exercise involving all levels of the workforce in a review of how to be more cost efficient. A similar process undertaken at BHP's Blackwater mine some months ago shaved about $5/t off costs. Seymour said the exercise could potentially reduce Crinum's mine site costs by 25%.

“The market is extremely competitive right now and the lowest cost producers are going to be in business at the end of the day,” he said. “We absolutely expect Crinum to be at that point. There is too much coal supply chasing too little demand — the demand's gone down at the same time that a number of new mines have come on stream.”

Safety has received a lot of focus at Crinum and it is one thing BHP management is particularly proud of. Crinum has reported the lowest lost time injury frequency rate of any active longwall mine in Australia and the lowest lost time injury frequency rate of any mine in Queensland.

“Except for Moranbah North,” Seymour added, “which is not quite an active longwall yet. Moranbah North is lower. We recognise Shell does have a good safety program and we'd look to borrow some of their ideas.”