It is now striving to reach its stated target of 65 cutting hours per week, managing director Tony Haggarty told the UBS resources conference in Sydney.

“The engineering teething problems mostly resolved, for example shearer set-up, picks and hi-set valves,” he said.

“The main issue was automation software, which is now installed and working.

“Operator skills are improving and CAT/Bucyrus will be supporting until the longwall reaches design performance.”

In its September quarterly report, Whitehaven revealed its Narrabri longwall ramp-up was continuing slowly as start-up engineering issues continued to hamper production and that it expected that the automation software issue should be resolved by early November.

“Shift production of 20 kilotonnes has been achieved, daily production of 30Kt has been achieved, weekly production of 140Kt has been achieved, and monthly production of 500Kt has been achieved,” Haggarty said.

The current 6Mtpa target is based on 65 cutting hours per week. Industry best practice is about 90 hours per week, stretching to 100.

“Narrabri has underground coal-handling capacity and is approved to 8Mtpa,”

Haggarty said.

An upgrade to the Stage 1 coal-crushing system would give 10Mtpa surface handling capacity, but the mine would need to continue to improve development rates to ensure continuity of longwall production, he said.

The company revealed Narrabri produced a paltry 512,000 tonnes during the September quarter, of which 424,000t was from the longwall.

“As with any installation of a new longwall into a new mining environment, there is a significant learning curve as experience is gained with the mining conditions and the machinery,” it said when it released it September quarterly report.

“The Narrabri management and workforce are responding very well and the focus now is on achieving consistent daily and weekly production at the targeted production rates.”