UNDERGROUND DRILLING
Beyond the metres metric
As recent technology developments are showing, there is more to the underground drilling sector than productivity alone, Dan Gleeson argues
Deep Automation for drilling can significantly improve the bottom line for underground operations through greater precision and optimised processes, enabling up to 30 % faster mine development rates and up to
70 % shorter stoping cycles, Epiroc says
In underground mining, the load and haul part of the process tends to steal the limelight, with mine sites typically looking to make incremental changes to these more mobile machines for productivity benefits ahead of the drilling and bolting fleet.
Yet, when it comes to the combination of operational safety and efficiency, the imperative shifts.
At the forefront of this movement, Mine Master says, is the Roof Master 1.7KA, a selfpropelled roof bolting rig developed through a collaboration between Mine Master, J. H. Fletcher and KGHM Polska Miedź S. A.
Specifically engineered to meet the rigorous demands of medium-height seams, the development of this automatic roof bolter was not merely a commercial endeavour but a direct response to urgent safety needs, Mine Master says.
The project was initiated at the request of health and safety departments of KGHM Rudna mine – an operation known for its demanding working conditions. The currently mined orebody lies at significant depth, roughly 844-1,250 m below surface, which results in high virgin rock temperatures and difficult climatic conditions.
In Rudna, virgin rock temperature has been reported at about 35 ° C at 850 m and 46 ° C at 1,200 m.
The mine is also one of the most seismically active areas within KGHM’ s underground asset base, with potential rock-burst hazards and ongoing risk related to roof falls and instability of underground workings. Roof bolting is therefore a critical safety activity performed in conditions of high thermal load, rock mass stress, dust, gas-related precautions and limited working space.
To address the inherent dangers of manual or semi-automated bolting – where operators can be exposed to falling rock and hazardous dust during drilling and bolt installation – Mine Master and J. H. Fletcher worked closely to develop a new roof bolting solution designed to offer improved safety credentials.
The core innovation of the Roof Master 1.7KA machine is its patented fully-automatic bolting mast. Unlike traditional rigs that require manual intervention for loading or positioning, the 1.7KA features a specialised magazine capable of holding 10 bolts – either 1.6 m or 1.8 m in length – alongside two drilling rods( a starter and a finisher). The machine can install both resin and mechanical bolts, including 1.6 m bolts in workings with a minimum height of 2.3 m and 1.8 m bolts in workings with a minimum height of 2.5 m.
Key technical innovations include:
• A patented J. H. Fletcher drilling and bolting apparatus that combines a multi-bolt magazine and an automated manipulator that retrieves individual bolts and feeds them directly to the drilling mast, eliminating the need for manual bolt handling during the installation cycle;
• Adaptive Drilling System: The rig uses an intelligent drilling system that automatically adjusts parameters based on the hardness of the rock, which can reach up to 200 MPa;
• On-line parameter registration: All bolting data is recorded in real-time, allowing for immediate analysis of the installation quality and geological conditions; and
• Remote readiness: The system is designed for remote control, paving the way for teleremote operation from the surface or a safe distance from the heading.
The transition to full automation serves more than just safety; it stabilises the production cycle. During testing at KGHM Rudna, the machine established clear performance benchmarks. In good conditions( level, dry and non-stratified roofs), the 1.7KA achieved a capacity of at least 12 expansion bolts per hour or 10 resinglued bolts per hour.
International Mining | JULY 2026 21