Whitehaven, which increased production year-on-year by 24% in the September quarter to 1.3 million tonnes, said the lack of skilled miners was causing weekly development metreage to fall below plan despite favourable geotechnical conditions.
It is also preventing full utilisation of the four continuous miner units available and has resulted in a shortfall of approximately 1400m against plan at the end of October, representing around four weeks delay at current development rates.
“An additional contractor, SBD-Delta, is currently mobilising its experienced people to supplement development at Narrabri while Narrabri employees are trained for longwall operation,” Whitehaven said.
“This will provide additional experienced people for development. However, if performance continues at the current rate, the shortfall in development metres against plan is likely to increase by mid-February, with a consequential delay in longwall commissioning of up to eight weeks, to mid-April.”
Delivery of longwall equipment to site is on schedule, with the machine now 95% complete on site.
Development of the main gate and tail gate roads for the first longwall panel is on the critical path for commencement of longwall mining. Mining conditions underground were “excellent” and development rates had improved as skills and experience had grown and as development had moved away from pit-bottom setup into normal main road and longwall gate road development, Whitehaven said.
Pre-drainage of carbon dioxide from the coal seam is working well with an inventory of drained coal now in place and confidence in gas extraction methods and gas modelling continuing to grow with experience.
Narrabri development produced 106,000t of ROM coal during the September quarter, an annualised rate of 424,000tpa.
A total of 339,000t of coal has been produced from Narrabri up to the end of September. Sales of more than 235,000t of Narrabri coal have now been made with coal stockpiling and handling systems and coal quality meeting expectations.
Ongoing review of Stage 2 costs, including tendering for all major components of the work, has not identified any material change to the budgeted capital cost of about $300 million.
Construction of Stage 2 surface facilities including the CHPP, ventilation shaft and other ancillary works is nearing completion and remains on budget.