UNDERGROUND DRILLING
‘ Stable and safe’ in demanding environments
Another company expanding its global reach is Poland-based Mine Master, which was recently awarded a contract by a customer in Egypt for 16 Roof Master 2.320AWK-MH bolters and 11 Face Master 2.320 drill rigs.
The Roof Master 2.320 AWK-MH is a two-boom roof bolter designed to secure ceilings and sidewalls in mines and tunnels with a cross-section range of 5 x 5 m to 6 x 9 m. A bolting mast is mounted on one boom, and the other is dedicated to handling safety nets in the form of sheets weighing a maximum of 80 kg.
The operator is protected from dust and rockfall by the air-conditioned cabin, which complies with FOPS and ROPS safety standards. The cabin
is used by a single operator to control the telescopic boom and the mesh handler, which is designed to pick up and install mesh along the roof and / or walls throughout the entire cross-section of the excavation.“ This not only increases safety and productivity, but also facilitates access to hard-to-reach areas,” the company says.
In many cases, additional mobile lifting platforms are used to install the mesh, which can be very dangerous if people have to walk under an unprotected area during the anchoring process. Solutions are also used to hold the mesh directly on the bolting mast, which reduces the efficiency of the machine’ s work at the face and considerably extends the mast structure and other moving parts, which require increased maintenance costs.“ For this reason, the use of the above-mentioned Mine Master solution with a dedicated boom and gripper significantly improves the operator’ s safety,” Mine Master says.
The bolting rig is equipped with a 13 kW MM13 drifter and a magazine for eight resin bolts. It can drill bolts with a maximum diameter of 25 mm and a length of 3 m. The hydraulically controlled drilling system offers a range of functions to increase efficiency and work safety, and is based on DFLR control( DFLR – pressure, flow and power controller).
To minimise downtime and facilitate maintenance, the Roof Master 2.320 AWK- MH is equipped with solutions that support servicing.
The central lubrication system ensures key components are properly lubricated without the need for manual operation, with concentrated measuring points and easy access to critical machine components allowing quick assessments of the most important parameters of the hydraulic and electrical systems, the company says. The Basic Monitoring System, meanwhile, enables quick diagnostics of travel and working systems, visualisation of operating
The Roof Master 2.320 AWK-MH is a two-boom roof bolter designed to secure ceilings and sidewalls in mines and tunnels with a crosssection range of 5 x 5 m to 6 x 9 m
parameters on the operator panel and data recording on external storage media( SD card, USB flash drive).
Master Mine says:“ The Roof Master 2.320AWK-MH is the ideal solution for working in difficult mining and tunnelling conditions, while ensuring high performance and reliability. Its design allows for stable and safe work even in the most demanding environments.
“ The installation of bolts and mesh is carried out in safe conditions, and the operator’ s work efficiency and machine service are supported by numerous systems monitoring the machine parameters.”
The‘ foundation’ for better mining
Development drilling is critical to underground mining progress, yet it is vulnerable to inconsistencies, especially in manual environments.
At the Haile gold mine in South Carolina, where OceanaGold is expanding operations from surface to underground mining, these challenges were pronounced, according to Hexagon. The region had no deep-rooted history of underground mining, and the local workforce – 85 % of which is sourced from the surrounding community – needed upskilling.
Drilling at Haile, conducted with analogue Sandvik DD421 and DD422i jumbos in a boltbore configuration, lacked digital alignment tools due to the risk of sensor damage during bolting, the company says. This left drill alignment dependent on operator judgment and manual marking – leading to variation in hole placement, frequent rework and inconsistent blasting. Overbreak averaged 16.9 %, well above the target of 10 %. Poor fragmentation, unplanned material movement and cycle delays were diminishing efficiency and raising costs, ultimately reducing asset value and profitability, Hexagon says.
To address these challenges, Hexagon partnered with OceanaGold to trial its Development Optimiser system.
This solution includes wireless sensors temporarily mounted on drill booms during drilling, a tablet interface and a cloud platform. It offers real-time drill alignment guidance and performance feedback – allowing operators to consistently hit design targets, regardless of experience, the company claims.
Crucially, the system is designed with bolt-bore rigs in mind. Sensors are removed prior to bolting to prevent damage, ensuring operational compatibility without requiring fleet changes. Additionally, this systemagnostic design supports integration into varied underground environments.
In late 2024, a three-week trial was conducted using a dedicated Sandvik DD421 jumbo. Six operators participated, receiving coaching and working through a structured competency checklist. Haile’ s engineering team surveyed each blast to measure overbreak and profile accuracy.
“ The impact was immediate and significant,” Garrett Doll, Hexagon’ s Team Lead, Service & Support, USCA, said.“ Overbreak dropped from 16.9 % to 10.8 % – a 35.6 % improvement. Alignment precision increased, reducing rework, re-drills and improving predictability for follow-up tasks like bolting and scaling.
“ These outcomes not only improved individual performance but smoothed entire development cycles.”
Operational implications further validated the trial’ s success, according to Hexagon. Across Haile’ s fleet of three jumbos, which together handle roughly
32 International Mining | JULY 2025