Whitehaven, which has recently completed a $5.1 billion merger with Aston and Boardwalk Resources, has also announced June 19 as the completion date for the sale of 10% to J-Power Australia of its Maules Creek project in NSW.

“The installation of the longwall is a significant milestone in the development of the project,” Macquarie said. “The longwall construction required 10,000 tonnes of equipment to be transported underground and assembled.”

With commissioning underway attention shifts to the behaviour of the goaf roof as the longwall advances, according to Macquarie.

“There is potential for the goaf to ‘hangup’ and create a hazardous windblast environment due to the properties of the strata above the coal seam,” it said.

“Whitehaven has hydrofracced sections of the strata above the first longwall panel to aid the roof collapse in the goaf.

“The company will monitor the roof’s behaviour to determine the extent of hydrofraccing required, if any.”

Whitehaven managing director Tony Haggarty said on Wednesday that the installation of 10,000 tonnes of equipment with installed power of 7 megawatts and the commencement of longwall commissioning completed the construction and development phase of the project.

A three-month commissioning and ramp-up program is underway to bring the longwall to full production.

The longwall is engineered and scheduled to produce approximately 6Mt of raw coal per year.