Shielding and Robotisation: A New Integrated Concept for Enhancing Safety and Efficiency in Drill-and-Blast Operations

Shielding and robotisation are opening up new perspectives for underground drill-and-blast development. By isolating the high-risk area near the face using a mobile, double-barrier shielding system, the presence of personnel in this zone can be entirely avoided. This shielded system is complemented by an integrated buffer storage unit for the mined material and a controlled material transfer through the shields. Decoupling blasting, material handling and also ventilation not only enables significantly shorter cycle times but also reduces safety-critical operations. Robotic or teleoperated equipment performs all tasks within the enclosed zone, laying the foundation for a new generation of drill-and-blast operation. While several relevant modules are already available, more key developments and also the implementation of the full system requires further research and development – offering the potential to fundamentally improve safety and efficiency in underground drill-and-blast operation.

1  Introduction and motivation

In underground mining roadway development the area at the face is one of the most dangerous work places in mining. The need to fully ventilate this area after each blast not only limits personnel deployment but also the maximum number of possible blast cycles per shift. Despite intensive automation approaches for individual work steps, the traditional drill-and-blast cycle remains largely characterized by human presence on site.

At greater depths or in sensitive mine areas, ventilating the blast gases is usually only permitted when personnel are absent, e. g., during shift changes. This limits advances to rarely more than three strikes per day. The desired increase in efficiency thus fails due to a bottleneck necessary for safety reasons, which could previously only be circumvented through complete process automation or alternative advance methods.

2  Concept idea: Blocking the ventilation path

A new overall concept addresses this issue (Figure 1). Instead of completely replacing the process, the hazardous area near the working face is to be consistently sealed off from the rest of the mine (1). A dual, movable weather barrier system reliably separates the contaminated zone from the rest of the mine workings – both in terms of gas dispersion and physical access (2). The redundancy of the two-bulkhead principle allows for an additional safety margin for critical situations or maintenance interventions.

Within this sealed-off area, robotic or remotely operated systems perform all activities of the blasting cycle – from drilling to loading and securing to material removal. During normal operation, this area will no longer be entered by personnel. This enables a complete decoupling of time-critical processes from the availability of ventilated, safe working conditions.

The system is complemented by a mobile buffer storage facility that collects the excavated material and transfers it to regular mine operations. This not only makes the tunneling cycle more flexible, but also decouples the logistics at the tunnel face – with the potential to parallelize processes that previously ran sequentially.

3  System overview and modules

The overarching goal is a contamination-proof, robot-assisted tunneling area with clearly defined handover points to the rest of the mine. A key component is the mobile ventilation bulkhead, designed as a functionally integrated unit. A current concept study favors a two-part variant: A front bulkhead serves as the primary gas and pressure wave containment, while another, rear bulkhead completes the separation. Both bulkheads provide controlled access for materials, equipment and utilities such as power and air.

Material logistics are handled via an integrated intermediate storage facility – a crawler-based system with a receiving unit, a pre-crushing unit (if applicable) and a conveying unit. This system temporarily stores the debris from one or more blasting cycles and transfers it through the bulkheads in a controlled manner. This modularization allows blasting and material removal to be carried out independently of the overall ventilation cycle.

In the active tunnel face area, robotic units – such as a remotely operated loading or securing robot – take over the tasks of previous advance teams. The entire process can be controlled and monitored from a safe distance. Initial demonstrators, such as the charging system tested by ABB Mining and LKAB (3), already demonstrate the technical feasibility of relevant core processes (Figure 2).

4  Aspects in realisation, research topics and first results

The implementation of a sealed, robot-assisted blast and drill system poses a number of interdisciplinary challenges. While proven technologies already exist for many aspects, combining them into a functioning overall system places high demands on technology, safety and process logic.

A key aspect concerns material logistics in the sealed area. The excavated material must be reliably collected, temporarily stored and then transferred in a controlled manner – without blast gases escaping or the sealing functions being compromised. The planned mobile intermediate storage facility offers a potential solution for buffering excavated material. The precise design of the passage through the sealing, e. g., using a sealed airlock or sealable material shafts, is currently still the subject of conceptual considerations.

The bulkhead system itself also poses specific requirements. It must not only be gas- and pressure-wave-resistant, but also mobile, relocatable and flexibly adaptable to different tunnel cross-sections. A bachelor’s thesis at the University of Leoben (MU Leoben), Leoben/Austria, investigated two variants – a modular weather wall with sealing profiles and a mechanically movable mining machine with an integrated sealing lip. Both systems were evaluated in terms of setup time, tightness, robustness and logistics. Initial theoretical considerations of pressure wave loading after blasting provide the basis for the design of such a module.

Another research topic concerns robotics/teleoperation in work areas that are not directly visible (4, 5, 6). While existing systems are already being used successfully in some technical areas, orientation, long-range visibility, redundancy and system diagnostics in the sealed space – and beyond that in the harsh environment of underground mines – place new demands on sensor technology and human-machine interfaces. Maintenance and availability aspects are also of great importance, as physical access is not possible during quasi-continuous gas exposure. Redundant designs, robust assemblies and intelligent self-diagnostic procedures are essential here.

Initial findings from laboratory and field tests, such as ABB’s robot-assisted charging system (3), show that individual process modules are technically manageable (Figure 3). The described systemic approach was also presented at the Future of Mining Conference 2024 (1) and met with widespread interest – particularly with regard to its safety promise. However, the complete integration of all essential components into a scalable overall system remains the subject of future development work.

5  Conclusion and outlook

The proposed concept of a sealed, robot-assisted section at the tunnel face offers the potential to fundamentally transform underground blasting. The clear separation between the hazardous area and the rest of the mining infrastructure not only allows for multiple blasting cycles per shift, but also mitigates key safety risks.

Particularly in hard rock, this complete system deliberately relies on the proven drill-and-blast cycle – in contrast to alternative tunneling methods, such as those using special roadheaders – but expands its application possibilities through technological integration, particularly robotics and teleoperation. The decoupling of personnel, blasting, material transport and ventilation enables a new logic of tunneling: safer, more efficient and more autonomous.

However, humans are still indispensable for construction, maintenance and repair. The goal is to extend maintenance intervals as long as possible.

Instead of one blasting cycle per shift, at least two or three blasting cycles can be performed, which corresponds to at least a doubling of the tunneling speed.

The technical feasibility of the initial modules has already been demonstrated. The development of the complete system offers a broad field for further industrial and scientific developments – from material logistics and mobile infrastructure to control strategies for teleoperated/robotised systems.

Particularly with regard to safety-critical operating areas – such as deep mines, geologically unstable zones or facilities with special explosion protection requirements – the concept opens up a new quality in underground blasting.