The company said the Narrabri underground operation started to iron out glitches with its longwall in the March quarter with 1.31Mt ROM coal produced – up 23% from the December quarter.

The ramp-up is continuing positively to the target capacity of 6 million tonnes per annum.

At the end of the quarter the mine was producing at an annualised rate of 5.2Mtpa.

Record production levels of 152,000t per week were achieved during the quarter.

“Installation refinements continue to be made to the longwall resulting in improved consistency and increased production rates,” Whitehaven said.

“Narrabri continues to work with Caterpillar to overcome the remaining commissioning issues.”

Hardware and software modifications to the shearer are planned for the next quarter, which is aimed at lifting productivity levels, including other ongoing improvements as part of the longwall change-out.

Preparation is nearing completion for the first longwall change-out which is scheduled to take six weeks.

“Being the first change-out for the mine, detailed planning has been undertaken to ensure risks to time and budget are minimised,” Whitehaven said.

“All major additional resources and equipment to effect the change-out have been secured.”

Narrabri underground development continued during the March quarter, with longwall panel 2 development completed and ready for the planned longwall relocation.

MG 103 development is well advanced and maintains a positive development float, according to Whitehaven.

“Contractors Delta SBD completed their development contract at the end of March providing significant cost savings,” the company said.

“Based on current results and expectations, Narrabri is expected to produce approximately 3.65Mt of ROM coal in financial year 2013, with an average product yield of 95%.”

The longwall change-out is expected in June.

Performance of the coal handling and preparation plant continues to improve as de-bottlenecking efforts provide genuine benefit.

Throughput rates of up to 900-1000 tonnes per hour are being regularly achieved.

Thermal product moisture remains above acceptable levels whenever a pulverised coal injection fraction is produced in the CHPP.

“Efforts to reduce the thermal product moisture are underway and some success has been achieved to date,” Whitehaven said.

“The re-commissioning of the bypass crushing circuit remains on track for early May commencement.”

The benchmark price of Whitehaven’s metallurgical product, Newcastle semi-soft coking coal, has remained stable at around $US113.50 per tonne free-on-board in the March quarter and expected to increase to approximately $118-119/t FOB in the June quarter.

Whitehaven’s realised value for its thermal coal in the first half has been affected adversely by general weakness in the market price, adverse foreign exchange rates and relatively higher moisture/lower energy of Narrabri thermal coal.