TECHNOLOGY
“ In terms of Section 21 of the Mine Health and Safety Act( MHSA), the equipment supplied by OEMs must be fit-for-purpose,” he adds.“ If that equipment does not comply with the regulations, then the OEM can face both civil and criminal prosecution; as the PDS supplier to the OEM, we would also bear responsibility.”
For this reason, it is demonstrably in the best interests of PDS suppliers to ensure that they offer the technology bestsuited to the application. After significant research and risk analysis to determine what the best fit-for-purpose technology for surface, Booyco decided to use GPS technology for vehicleto-vehicle detection, and very low frequency( VLF) technology for pedestrian detection.“ It delivers specific warning, controlled slowdown, or stopping zone alerts around a vehicle when detecting pedestrians or other vehicles,” says Lourens.
However, the promulgation of the PDS legislation, and the looming implementation deadline of mid-2019, has also resulted in an explosion in the number of PDS suppliers out there, including some fly-by-night operators that spring up just long enough to sell a few systems before disappearing, leaving the buyers without support or recourse, should anything go wrong.
“ Ten years ago, we were one of three PDS suppliers in South Africa,” says Lourens.“ Today, there are over 40 operating in the market.”
And of these 40-plus PDS suppliers, only 28 are currently accredited, although this is a number that can change at any time. And while identifying and implementing the correct PDS technology for a particular operation is obviously the first – and most important – step. The fact that this technology will have a direct impact on site safety means that proper maintenance and support is just as important for the long term, which makes choosing a suitable supplier vitally important.
Risk assessment and implementation
Over the past year, the Mine Health and Safety Council( MHSC) has put together a committee that is driving PDS implementation, including risk assessment. The MHSC has also adopted the best practice guidelines laid out by EMESRT, which contain a variety of different scenarios for dealing with interactions between pedestrians, equipment and the environment( see Figure 3). They have also put in place appropriate models based on these different scenarios that mines can follow to achieve a risk assessment that is acceptable to the DMR.
According to Lourens, the work that EMESRT has done on standardising the functional requirements of PDS technology has also done a lot to align the industry.“ Before the standard, any PDS supplier or OEM could supply a mine with the technology that they believed was best for the application, and there was no real alignment and no real practical way to measure function and performance. Now, companies need to supply technology that complies with these functional requirements if they want to be accredited PDS suppliers, and this is something that is measurable, and therefore enforceable.”
Once a mine has completed their base risk assessment and identified their significant risks, then PDS suppliers such as Booyco can assist the mines in determining how technology can be best used to mitigate the site’ s specific risks.“ It’ s an involved process, but given the significant capital costs of installing PDS technology, ensuring that you are only installing it where it is needed and will have the greatest effect can result in significant cost savings, versus placing it on all equipment, or on the wrong equipment and then needing to replace it,” he says.
When it comes to the timeline for the three levels of control that specifically affect PDS technology, a lot is dependent on the level
EMESRT EMESRT
Figure 1: EMESRT 9-step hierarchical type model based around design, operate and react.
Figure 2: Unwanted event surface scenarios.
“ When it comes to the timeline for the three levels of control that specifically affect PDS technology, a lot is dependent on the level of complexity required for each one.”
of complexity required for each one. Level 7 is a basic warning, letting the operator know that there ' s a person, vehicle or piece of infrastructure within a specific distance of the vehicle. Level 8 is an advisory system that will suggest a course of action to the operator, such as to slow down or stop. And level 9 is an intervention, which will actually take control of the vehicle and cause it to slow down or stop.
While the basic warning level of technology is already operational – with varying degrees of success – Lourens says that the complexity of the algorithms required for the advisory and intervention levels of control will take significantly longer to finalise, although he is confident that this will be addressed in time for the deadline.
“ The problem is that the computational and processing power required for these control levels, as
18 _ QUARRY SA | JANUARY / FEBRUARY 2018