Our first strategic priority is achieving operational excellence – and that always starts with our number one value: safety.
Since the temporary sealing of the Grosvenor steelmaking coal mine in Queensland, Australia, in June 2024 following a localised ignition event, every decision has focused on a safe and staged re-entry underground. Progress at Grosvenor reflects not only technical achievement but also the extraordinary dedication, ingenuity and adaptability of our workforce.
Throughout the journey to re-enter the mine in August 2025, the team worked alongside the Queensland safety regulator, industry safety representatives and mines rescue teams to ensure every step was safe and considered.
Understanding the environment
From the outset, the mine prioritised understanding underground conditions without putting anyone at risk. The team developed a purpose-built, light-detection and ranging camera system which used simultaneous localisation and mapping (SLAM LiDAR). Lowered through boreholes, the ‘torpedo’ SLAM LiDAR device captured high-definition imagery and atmosphere data, enabling accurate 3D mapping of underground conditions. The data confirmed the integrity of the roof, ribs and conveyor systems was largely intact, with only localised damage. This novel application provided a foundation for re-entry and set a new benchmark for industry innovation.
The site also employed drones for high-resolution imagery, methane detection and airborne LiDAR, while laser scanning supported precision fabrication for shaft ducting and fan installation, as a critical part of the re-ventilation process.
These tools did not exist in the site’s standard toolkit before the incident and were developed or re-engineered in response to the challenge.
Overcoming challenges with innovation
From the early stages, the team recognised that the scale of the recovery was immense, with little precedent to follow. Multiple high-risk activities had to be sequenced and controlled, including ventilation installations, shaft recovery, dewatering, air-conditioning relocation and ‘knife gate’ seal construction.
At Shaft 5, which was filled to the surface during the initial sealing process, a reverse-circulation drilling method removed material at five metres a day, using pressurised water and air to push dirt and rocks to the surface. At Shaft 6, a ‘clamshell’ grab attached to a 280-tonne crawler crane excavated dirt packed into the ventilation shaft during mine sealing.
Industrial detergent mixed with compressed nitrogen formed a foam to help separate the underground and surface atmospheres as dirt was removed. Together with exhaust and forcing fan installations, these works were the backbone of the re-ventilation process – the step that ultimately ensured safe underground access.
These complex engineering tasks were meticulously planned, risk-assessed and executed with precision to ensure safety at every stage of the re-entry journey.
Looking ahead
The underground environment at Grosvenor remains stable, with monitoring systems providing accurate real-time data on atmosphere and airflow. As technical teams investigate the latest technology around the world to make it even safer underground, reconnaissance inspections and rectification works continue in rolling deployments.
Thanks to the innovation, discipline and collaboration exhibited, re-entry at Grosvenor has been successful and, most importantly, safe.
