Any study of industry injury statistics will highlight the level and nature of injuries being experienced by personnel working on or around continuous miners in roadway development, be it operating bolters, handling strata support materials, handling cables, hoses and ventilation ducting, slipping, tripping and falling off equipment, being struck by roof or rib or maintaining equipment.
While we continue to restrict roadway widths to 5.2 metres or so, build continuous miners capable of cutting and loading at rates of 40 tonnes per minute, and require people to get on board the continuous miner to install strata support within a few metres of the face from multiple drilling stations (often including 4m, 6m or 8m long tendons), we are going to continue to experience this level of injury.
In my view we need, as a priority, to develop technologies that allow both the miner and the strata support process to be operated remotely from a place of safety.
CSIRO’s Queensland Centre for Advanced Technologies and the University of Wollongong’s Automation and Robotics group are doing great work in this regard, as are a number of individual original equipment manufacturers.
However, it all needs to be integrated as a complete system, as well as developing and integrating other components such as continuous haulage systems and advancing the ducting and services.
Further, we have had limited experience managing the issue of man/machine interactions in the roadway development process and I expect that what is effectively full automation of the roadway development process will introduce a few challenges.
Automation of the roadway development process will require well thought through change management processes in order to be successful. Unfortunately, the industry is not good at introducing new technology, systems or work practices and I expect there will be any number of potential and perceived threats or issues as systems are developed to allow people to get out of the immediate face area, including the issue of job security.
Best practice mines currently demonstrate that high-capacity roadway development systems require more people to operate them, not less. I anticipate that automating the roadway development process will change the roles that people perform, rather than eliminating them.
What is also of concern is the situation at some mines where different crews have differing opinions regarding the suitability or otherwise of new technology and practices, resulting in the successful introduction of those new technologies and practices being impacted or constrained.
Unless we develop better ways of introducing new technology and equipment and managing change I fear many are not going to realise the potential of current research.
Preparation of a Handbook of Roadway Development Practice for ACARP has allowed me to focus almost entirely on this phase of the longwall mining process and I am amazed at the variability in development productivity across the industry.
Richard Porteous has done some great work across the Xstrata group of mines to understand the roadway development process and to quantify the effect of equipment type and capacity (including continuous miners, shuttle cars and breaker feeders), support design and installation, and the potential benefits afforded by adoption of self-drilling bolts and/or continuous haulage systems.
His studies clearly indicate that adoption of these technologies could enable instantaneous operating rates of 8-10m per operating hour to be achieved; however, the real challenge is to sustain these rates on a consistent and continuous basis – hourly, daily and weekly.
Richard also made a number of observations about how the overall development process is managed at individual mines and the opportunities available to improve development performance through improved process management and control.
On reflection, I believe many of Richard’s observations are consistent with a “lean thinking” approach, a process improvement methodology developed and refined in the Japanese auto industry in the 1980s and 1990s.
Richard’s identification of losses (waste) in the development processes are consistent with the underlying principles of lean thinking, which seek to involve all personnel in the continuous identification and elimination of waste in all its forms.
A few mines have demonstrated the potential of lean thinking by utilising its principles to significantly improve panel advance cycle times, to develop auditable panel standards and shift handover practices, and to smooth out the development process to achieve sustainable improvements in development rates.
I believe this approach is relevant and appropriate to improving development rates, gas drainage drilling, longwall production and mine services.
The challenge the industry faces is the rigour of developing, auditing and continuously improving standards and the necessity for process managers to spend most of their time underground, challenging personnel to eliminate waste in the development process.
The real opportunity is improving roadway development performance to the extent that a single gateroad development unit can support a high-capacity longwall (with possibly another development unit in mains development).
To achieve this, we need to focus on the development and implementation of the following technologies and systems:
- First and foremost, self-drilling roof bolts and rib bolts.
- Secondly, automation of the drilling process to enable bolts to be installed consistently and repeatedly to predetermined standards and support designs.
- Thirdly, either automation of the mesh handling systems or development of an alternative skin confinement system such as ToughSkin (manual installation of mesh defeats some of the benefit of developing self-drilling bolts and automated drilling systems – getting people out of the immediate face area).
I also consider that we should perhaps start to challenge our current 5.2m wide roadway paradigm.
We now want to put automated bolting and meshing systems on board continuous miners, and also consider automated long tendon installation – where is it all going to fit?
One option may be to mine a wider roadway (say 6.0-6.5m) and create additional real estate on the existing machine chassis to which these additional systems can be fitted.
A wider roadway may require additional strata support, but with more efficient on-board strata support systems in a wider roadway, improved advance rates might also be achievable.