March quarter production at 355,000 tonnes was behind prior guidance with mining impacted by labour availability and slower than expected mining around a known major fault.

March quarter costs were $112/t, impacted by the fixed cost base spread over lower than anticipated sales in the quarter.

The Isaac Plains mine was impacted in late March by Tropical Cyclone Debbie. Thanks to preventative measures put in place prior to the cyclone reaching the site, there was no material damage incurred to critical company assets or other assets at the site.

However, the Goonyella rail network owner Aurizon advised track damage was extensive and would not be available for railings for about five weeks, which will affect Stanmore’s sales.

“With the expected delays to rail infrastructure arising from TC Debbie, June quarter costs are anticipated to be above life of mine levels as fixed costs such as take- or-pay commitments for infrastructure providers, together with other fixed overhead costs, will all remain payable during the expected delay period,” the company said.

Stanmore expects a ramp-up in manning in the June quarter together with an additional excavator will contribute a further 300,000 bank cubic metres above the March quarter result, while additional dozer hours are expected to contribute 200,000bcm. 

This increase in pre-strip will enable an additional cast blast of 300,000bcm to occur in the June quarter.

In addition to increased excavator availability in the June quarter, the dragline lineal progression will be significantly improved by not mining known blocks of coal seam repeats, where coal losses were experienced in the March quarter. 

Stanmore said the increased speed of the dragline was anticipated to result in an additional 800,000bcm prime waste in the June quarter.