Idemitsu said it was investigating all options to minimise the impact to the operation of the mine and to continue transporting coal to the port.

The company said an extended closure of the rail line would cause serious interruptions to the operation of the Boggabri mine, unless a temporary haulage solution could be found.

“Idemitsu Australia Resources is engaging with relevant state and local government authorities to seek approval for this temporary solution and is committed to keeping stakeholders informed regarding the outcome of these discussions,” it said.

The Australian Rail Track Corporation has advised the company that repairs to the track and Cox’s Creek Bridge were still some time away from being completed and could provide no firm timeframe for returning the track to service.

Whitehaven Coal has decided to reschedule longwall maintenance at Narrabri.

The move is a blow for Whitehaven, which has only just ironed out longwall automation problems and was attempting to gear up production to 65 cutting hours per week.

Whitehaven managing director Tony Haggarty said the track closure did not affect its open cut operations or the Gunnedah coal handling and preparation plant.

“We do not have capacity at Gunnedah CHPP to handle all Narrabri coal. However, short-term trucking would reduce the impact of the rail closure and allow production at the Narrabri mine to continue while the track repairs are completed,” he said.

“Other actions, including rescheduling of required longwall maintenance at Narrabri, reconfiguration of stockpile facilities, maximising coal deliveries from the open cut operations and optimising shipping schedules, are also being put in place.”

Trucking was only being considered as an interim measure and any approval would be short-term, he said.