The company, which yesterday reported a 53% increase of ROM coal production in the June quarter to 2.2 million tonnes, is hoping that efficient longwall mining at Narrabri will improve the quality of its thermal coal product, which has a low energy value.

“The change-out presented the opportunity to make a number of improvements to the longwall,” the company said.

“New automation software has been installed and is undergoing commissioning led by experts from Caterpillar. Pending outcomes of the software trial performance, the plan is to move to bi-directional cutting on completion of the trials.”

Other modifications were carried out during the change-out period to prevent shearer roll-back and changes to chock isolation valves and hi-set POCV valves.

Regular maintenance was also completed on the shearer and a number of roof supports.

Weekly production is expected to return to regular production levels over the coming weeks, the company said.

Narrabri produced 792,000t of ROM coal in the June quarter. The company’s total ROM coal production for the year was 9.0Mt compared with 5.3 Mt in the previous year.

“The significant increase reflects the ongoing ramp up of the Narrabri longwall operation,” the company said.

“Productivity improvements in Narrabri mine are being vigorously pursued.

“Mine development rates are ahead of schedule with completion of development for the third longwall panel expected by end of Q1 FY2014.”

The energy level of thermal coal product remains under close scrutiny with actions targeting moisture and ash levels being implemented.

“Feedback on an improved result will be available in Q1 FY2014 following the ramp up to full production of the longwall following its successful relocation,” Whitehaven said.