The company reported quarterly RoM production of 734,000 tonnes and 610,000t of saleable coal.

Isaac Plains achieved historic records for half year production with the complex operating at much improved rates of about 95% of the nameplate capacity of the Isaac Plains CHPP.

Because of this Stanmore approved capital expenditure of approximately $7 million to increase the CHPP capacity from its nameplate 500 tonnes per hour to 600tph RoM feed.

"This will provide an annual capacity of more than 4 million tonnes RoM per annum to support the rapid coal uncovering by the dragline and the higher RoM production rates at Isaac Downs, especially in the next two years," the company said.

"Performance in the second half of the year was more representative than the first half of the year and indicates expected production rates going forward at Isaac Downs.

"The forward plan is for the dragline to transition to Isaac Downs where it will operate for the next two to three years at strip ratios substantially lower than Isaac Plains East."

Stanmore said the dragline at Isaac Plains East continued to operate at rates well above set targets, while the EX3600 excavator at Isaac Downs also performed well.

Stanmore's Caterpillar 6060 600t excavator was transferred from Isaac Plains East to the Isaac Downs project area on October 4 and started mining overburden.

"This increased the bulk mining capabilities for overburden at Isaac Downs within the expanded mining area available following mining lease approvals granted in Q3 2021," the company said.

"An additional Golding EX5500 machine was brought back into service at Isaac Plains East to complete pre-strip activities in front of the dragline and mine the coal uncovered."

The dragline will transition to the Isaac Downs mine during the first half of 2022 and, following a maintenance overhaul, will begin mining activities in conjunction with the start of the recently announced new mining contractor, EPSA.

"The awarding of the coal haulage contact, completion of the highway underpass work and construction of the flood levee scheduled for Q1 2022 will complete the final work required for Isaac Downs to ramp up to full annual production rates," Stanmore said.

"During the quarter, construction activity at Isaac Downs continued.

"The construction of the new underpass bridge and the associated permanent highway deviation was substantially progressed such that all public traffic is expected to be diverted to the new section of highway over the new highway bridge in early February."

Stanmore said it progressed the dedicated haul road to connect Isaac Downs with Isaac Plains and the section under the old highway would be excavated and the final pavements completed.

"Rain during the quarter had some impact on the construction activities causing delays, however, works continued and project construction will be substantially completed for the major packages before dragline operations are transferred to Isaac Downs," it said.