The first cargo of 60,000 tonnes to Japan was previously scheduled to be made in the September quarter, but Pike said it had encountered some “teething problems”, which had slowed the expected production ramp-up, pushing back the shipment by six weeks.

Unlike most coal producers, Pike will use hydro mining at its namesake underground coal mine in New Zealand’s South Island.

The company now expects to start blasting the coal with high-pressure water cannons in November.

Pike chief executive Gordon Ward said to overcome the delay in production ramp-up, the mine plan had been modified to access the first hydro mining extraction panels closer to the pit bottom.

The company’s initial 2009 plans were set back by a rockfall, which blocked the mine’s ventilation shaft.

While Ward noted that good progress had been made by restoring full ventilation in early June, building up production since then had taken longer than anticipated because of “relatively minor but time-consuming” faults in brand-new heavy cutting machines and the need for mining crews to become familiar with the equipment.

“Recent modifications made to the machines together with additional training and increased familiarisation by the mining crews is already seeing significantly improved performance,” he said.

“Given the mining experience to date and the need for a reasonable level of work in stone over the next couple of months, it is prudent to apply a more conservative timeframe for completion of the ramp-up, which pushes out the first coal shipment date.”

The company said the roadheader and one continuous miner were in operation with the second CM to go underground this week.

The pit bottom infrastructure is complete, including a 10km coal slurry pipeline that carries crushed coal to the coal preparation plant, eliminating the need for trucks to do the job.

“The coal slurry and flume pumps have been commissioned, the coal crusher and coal flumes tested, electrical installations completed, and the first full test run for loading export coal at the Ikamatua rail loadout facility will be in the next month,” Pike said.

Pike will also supply coal to Gujarat NRE Minerals, the Australia-listed subsidiary of India’s Gujarat NRE Coke, as well as India’s Saurashtra Fuels, at the price of $128/t.

Pike shares had shed A2c to 90c in late afternoon trading.