The presentation by managing director Tony Haggarty revealed that the ventilation shaft, coal handling and preparation plant and other key Stage 2 facilities were well advanced.

Its Stage 2 capital estimate of $300 million remains on track following the award of most Stage 2 contracts, it said.

The first two longwall panels will mine a 4.2 metre bottom section and will provide experience of caving and geotech characteristics of the mine, according to Whitehaven.

“There is potential thereafter for top coal caving (TCC) which could recover most of the 8-9 metre coal seam, increase resource recovery (+300Mt) and extend mine life,” the company said.

“TCC would also provide lower development costs with potential to reduce development continuous miner units from 3 to 1.”

Gas management and spontaneous combustion management costs could be reduced and increase longwall production from 6 million tonnes per annum to 9Mtpa with low additional underground capex.

The Narrabri longwall has been designed with an option to retrofit TCC during a normal longwall change-out.

The downside of TCC is that the mine would need a substantial capacity upgrade to surface facilities and would probably require washing of all coal.

Whitehaven, which recently decided not to go ahead with a proposed sale after receiving bids for the company that it did not consider fair value, is well positioned with large resources and reserves of high quality coal, the company said.

It has a mix of metallurgical and thermal coal products and efficient, flexible open cut mines, and competitive costs.

Substantial growth will come from both Whitehaven’s Narrabri and Vickery deposits and the company has an established rail and port capacity with 11% share of Newcastle Coal Infrastructure Group, Whitehaven said.