PDS — what do you have to do?

PDS — what do you have to do?

By Eamonn Ryan

If surface mines do not have a risk assessment and a traffic management plan, they could be served with section 54 notices. 

Legislation promulgated by the Department of Mineral Resources (DMR) requires all mines to take steps before 2020 to physically prevent contact between mobile machines and humans or to install proximity detection systems (PDS) on trackless mobile machinery (TMM) for effective collision management. These measures need to be in place by no later than December 2020, failing which severe action will be brought against responsible parties and mine owners.

The process at Aspasa, explains the organisation’s director Nico Pienaar, commenced two years go (approximately December 2017), at a time when few people had any understanding of what PDS meant. Prior to that, government wrote legislation requiring the implementation of PDS, “but there was nothing to implement, as the technology did not exist,” says Pienaar.

There are a number of parties involved in the process, including PDS suppliers and the OEMs that prefer to have the system integrated into their vehicle at manufacture, rather than the post-manufacture addition of a third-party system. End-users are also involved. This process is continuing, with the many OEMs and third-party suppliers all at different stages of completion, with certain OEMs attempting to accelerate the process by providing machines to PDS suppliers. There is an increase in the number of lab scale tests conducted by the University of Pretoria (UP). Pienaar notes that the UP tests have acted as a game changer in the PDS industry with a well-defined evaluation process. “So far, all the PDS suppliers that have been evaluated have not met expectations and are modifying their solutions with the objective of retesting.” 

“We have frequent meetings with OEMs such as Bell, Komatsu, and others who must build it into their machines. The system is an extension of systems that many newer cars have, which warns you if you’re about to reverse into anything. The PDS stops the vehicle and to achieve this, requires an off-site base to monitor proximity and to cut the motor.”

Anyone buying a vehicle by now for use on a mine should have the black box PDS in place, says Pienaar. However, in terms of what a quarry owner can and should be doing ahead of the development of PDS, and the more important step, says Pienaar, lies in operational changes taking place on surface mines in the form of traffic management plans.

Traffic management plans

“Proper risk assessments — and I emphasise ‘proper’ — need to be done first in order to know how to comply and it is precisely for this reason that Aspasa is holding workshops and developing documentation that will guide our surface mines in future.” Pienaar explains that in order to comply, mines’ management teams need to understand how to do effective risk assessments. These should be dynamic plans that require review at regular intervals to identify additional risks as the mine progresses. From these risk assessments, traffic management plans are devised and staff training held.

Quarries also need to understand PDS control systems’ effectiveness and how to implement traffic management plans that remove people from harm’s way. They must understand that by the time TMM or alternatives become mandatory where risk exists, the technology will still not be foolproof and mine owners will still need to look at other ways to reduce the risk.

With fatalities on mines increasing — though not on quarries — there is no way the industry can ignore the requirement but should rather embrace it and find the right solutions that will work on individual mines. It is also important to know that there are alternatives to expensive technology if mines do proper traffic management plans and implement them effectively.

“A surface mine manager must look at the risks associated with his/her mine and identify each risk associated with TMM. This involves looking at the road and pedestrian networks, keeping them apart, and managing the points at which they intersect. There is a tendency in these reports to not find any risks — but until you find them, you cannot manage them.” He gives the example of some companies that modify Hilux LDVs with a high cage to protect personnel — but in the process create a new risk of the LDV toppling over.

There must also be substantial road sign warnings and barriers capable of stopping a fully loaded truck — not small white stones, as seen on many mines. Vehicles must maintain the same level of roadworthiness as on a national road, as well as managing the space between vehicles and people. “You also don’t have to put a PDS in every vehicle — only those at actual risk according to the risk assessment. On some diamond mines, they have cordoned off at-risk areas for pedestrians and consequently have exemption for PDS — because there’s no pedestrians to harm. It’s the same concept as, you don’t need a hard hat in an office.”

According to Pienaar, in 2016 there were nine TMM fatalities; in 2017, 12; and until November 2018 (the latest figures), there had been 12, “trending for 13”, says Pienaar, and therefore steadily worsening.

The process is being closely monitored by government, through the Mining Regulation Advisory Committee (MRAC), which is poised to review the UP testing, and based on this review will determine the way forward, and dates of implementation.  “A process has started with the DMR again on progress, which will include: the new roadmap; an aligned regional messaging; traffic management plans; progress on technology development; availability of reportable incident data to update the incident analysis; progress on the pilots in place; and discussions on dates,” says Pienaar.

There are nine levels to implementing a PDS, but Pienaar points out that if steps one to six (including the traffic management plan) are done and the risk is mitigated (as in diamond mines), then it may be that the mine does not need to install PDS in its vehicles. “However, companies that are going to need to implement PDS should at least be at level seven by now: operator awareness.”


Pienaar lists a number of challenges facing the process:

  • The danger of a fitted PDS, says Pienaar, is that in the event of an accident, there will doubtless be a court case, with the OEM alleging that the PDS supplier interfered with its systems, and the supplier blaming the OEM.
  • There may also be arguments regarding the data connection, as the system relies on mobile telecoms technology.
  • A company which already has vehicles without a PDS system installed, may not be able to deal with a single supplier, as it may have a mix of Bells, Komatsus, and others. A company would want a single system.
  • Some systems involve pedestrians wearing a wristband with a transponder that emits a signal. However, if the pedestrian forgets to wear the wristband, or a driver steps out of the vehicle and is not protected, there has to be a preventative system — this is part of the risk assessment.
  • It takes time to install these devices, and if a quarry receives a section 54 notice, they cannot simply call in a supplier to immediately do the installation. “Wake up now,” urges Pienaar, “because you’re not going to make it if you leave it to 2020.”
  • Aspasa is not aware of any supplier already fitting level 9 PDS — all are in the testing stage and are already running behind schedule.
  • The quality of risk assessments and traffic management plans may be disputed, but if they do not exist, a quarry can already be served a section 54 notice — and some have.

Booyco leads the way locally

One of the leading local PDS suppliers, active in the market since the first generation of PDS in 2006, is Booyco Electronics. It has in excess of 50 000 PDS installations to date — though not all level 9, which is being implemented.

Anton Lourens, managing director of Booyco Electronics, says: “One of the things we’re really pleased about was the establishment of various working committees through the Minerals Council, which has defined the process. That process is based on work done by the Earthmoving Equipment Safety Round Tale (EMESRT), an organisation formed some decades ago by the mining houses, with no regulators or suppliers involved, to develop a ‘best practices’ model. Levels 1–6 are administrative and engineering controls, up to a point where there is a trained, confident, licensed, and medically fit operator, and levels 7–9 being a comprehensive PDS culminating in stopping the vehicle should it be necessary.

“The process is not as complicated as it may seem. Aspasa has a road map which simply has to be followed, and this map is all about ‘doing the basics’.” - Nico Pienaar, Aspasa

“This model ascertained that if a PDS model was developed for the global mining industry, then 80–90% of accidents and fatality risks would be averted. In South Africa, this model was adopted by the Minerals Council and a working committee appointed, which now includes the DMR, to tailor the system to South Africa.” With the amendment to the Mining Health & Safety Act, this has now become law through the promulgation of Chapter 8, which relates to PDS and TMM.

“It is very much a risk assessment process to identify significant risk, and to then address that risk through what could be a PDS solution or various other options such as a traffic management solution. Companies have until December 2020 to comply with this provision of the Act.”

Anton Lourens managing director of Booyco ElectronicsAnton Lourens, managing director of Booyco Electronics. Image credit: Booyco

Lourens says he has spent considerable time — and tens of millions of rands — on R&D and product development, studying existing fit-for-purpose systems and tailoring one to South Africa. One of the misperceptions in the industry is that PDS itself will stop a vehicle. Lourens advises this is not the case: “PDS detects a potential threat and gives that information to the OEM through a defined interface and protocol, and it is the OEM’s responsibility to act accordingly through our control systems.”

There is a communication interface protocol ISO 21815 that deals with this interaction, whereby for example the OEM acknowledges it has received a threat warning. This protocol means that any PDS system can talk to any OEM across the world. There is a display monitor in the cab of each vehicle to which the PDS sends a message to the operator (level 7) or applies the brake (level 9). This is all recorded in the case of an incident (where there has been a failure of the system) to determine where the fault lies.

The challenge for most OEMs is that mining in South Africa is a small part of their global business, with consequent mixed responses by them: some are developing their interface quickly and others more slowly. Bell Equipment is the most advanced, says Lourens. “We expect that with Bell we will have our first surface customer where we can do a full intervention effectively. One of the challenges is that in South Africa, the approach to plant and equipment is that of a ‘Smarties box’, with a mix of different TMM equipment requirement on any one site.”

Most OEMs are not developing their own PDS, Lourens clarifies, but their own interface. Because OEMs are hesitant to have external systems interfere with their proprietary systems, Lourens explains that many are going the route of interpreting a parallel interface system on top of their proprietary systems and then using a gateway to migrate the data internally. All vehicles currently being bought should come equipped with such a capability for a third-party interface.

“By the time these systems are implemented successfully in mines, we have heard that it will be applied to other industries such as construction, forestry, farming, and more,” says Lourens.

Key aspect of the design: testing

Booyco undertakes considerable internal testing for proof of concept and design, thereafter engaging with external testing company Gerotek, which has a testing ground widely accepted within the mining industry and by OEMs to test their braking systems.

The Minerals Council has also put a process in place through UP, which has a division called Vehicle Dynamics Group that has developed a simulation model to test various scenarios. “This gives us an independent third-party report, which will determine whether the system meets expectations,” says Lourens. Testing is still under way.

It is this report which will determine whether a system is compliant. A few years ago, there were as many as 40 PDS suppliers; a number which has now been whittled down “quite drastically to five or six big players, including international companies”, says Lourens, as companies have come to understand the complexity of the system, and the financial investment required.

A key component of testing is tailoring the system to local conditions. Lourens says Booyco’s 12 years’ experience has been vital in this regard — but there have been false dawns. “One of the local idiosyncrasies is that we are a more labour-intensive mining industry than most markets, and familiarity with this has been one of our competitive advantages.”


Lourens posts a caution to a quarry industry that is already under cost pressure: “There are people marketing complex and expensive systems, telling quarry owners they need to implement PDS as a silver bullet. Whereas the biggest issue facing quarries is the lack of education regarding the PDS. Aspasa is hosting workshops throughout the country to educate quarry owners on what the Act says and what technology is available. They need to realise that PDS is not a silver bullet but part of a broader risk-assessment-based methodology in which you can in fact address a lot of safety risks without PDS. It should be your last resort.”

Booyco is an example of how hard the suppliers have worked. Pienaar says a number of firms, including Aspasa members, have also done advanced work, and there are others who could be at the same level. He adds that the process “is not as complicated as it may seem. Aspasa has a road map which simply has to be followed, and this map is all about ‘doing the basics’,” says Pienaar.


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