Fifty-five years of raise boring comes to an end at Mount Isa Copper Operations
The Raise Boring Department at Mount Isa Mines holds the unique distinction of being the only mine-owned-and-operated raise boring team in Australia. While operations at the copper mine are set to wrap up in April, the dedicated crew will continue their work at George Fisher Mine (GFM), which will serve as the team’s new home base.
The department’s story began in 1970, with the commissioning of a Robbins 81R raise boring machine, endearingly dubbed the ‘Wombat’ by the mining community. This machine was tasked with creating ventilation shafts for both the copper and lead underground operations.
This image demonstrates a drill string being drilled through to the next level where the reamer is attached to the drill string and the reamer head makes its way up cutting a hole in the roof of the tunnel.
Raise boring is a technique for creating large-diameter vertical shafts without using explosives. The Wombat is capable of drilling a pilot hole up to 800 metres deep, which can then be reamed to a diameter of five metres. This method is preferred for tasks such as ventilation shafts, ore passes, and cut-off raises, thanks to its efficiency and reduced ground disturbance.
Over the past 55 years, the Mount Isa Copper Operations (MICO) raise boring team has completed numerous major undertakings. A standout project was the N59 Ore Pass from Level 11 to Level 15, a 220-metre shaft drilled through challenging rock formations. To stabilise the hole and prevent collapse, drilling fluids were used before reaming it to a diameter of 3.1 metres.
Renowned for their outstanding safety practices and technical expertise, the team has set benchmarks for raise boring operations in Australia. Their capabilities have been called upon far beyond Mount Isa, with successful deployments at sites including Ernest Henry Mine, Glencore’s Newlands Coal Mine in the Bowen Basin and BHP’s Olympic Dam in South Australia.
The raise bore maintenance team with the last reamer head to be used at MICO. L-R: Peter Hankin - Fabricator, Nils Krutzfeldt - Mine Captain, Damien Finter - Reamer Specialist and Mick Chiauzzi - Senior Raise Bore and Drilling Services.
This is the ‘Wombat’ which weighs in at 65 tonne and is about 4 stories high at full extension.
A 4.5 metre reamer head is attached to the drill string.
The Mount Isa Mines Raise Boring Department will soon settle into its new home base at George Fisher Mine as the Mount Isa Copper Operations comes to the end of an era.
Mick Chiauzzi, Senior Raise Boring and Drilling Operations, reflected on the team's journey:
“I’ve had the privilege of working alongside many talented individuals who have each played a crucial role in shaping the department’s success. Their contributions have built a legacy we can all be proud of.”
For decades, the department has thrived on teamwork and a strong work ethic, qualities that have driven countless successful projects.
As the MICO chapter closes with the completion of the U688 stope cut off raise on 30 April 2025, a new chapter emerges, as GFM continues the proud tradition of raise boring excellence at Mount Isa Mines.