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Digging deeper - beyond access control

When it comes to managing access, the requirements of the mining industry present challenges of a complexity and scale that are in a league of their own.

These requirements raise the question whether the term 'access control' is an adequate description of the job at hand. Perhaps SAS-control would be more relevant. Mark Eardley of Turnstar Systems looks at the core issues for managing SAS (safety, access and security) in this demanding sector.

Mining is a hard and potentially highly-dangerous business. Common sense dictates that there is a world of difference between monitoring thousands of people in an office tower and managing the movement of staff at a large mine.

Piet Vermeulen's company, Card Control Systems, has been involved with access-control at mines since 1983. "On a big mine, staffing levels can run to over 7000 people. Providing safe and efficiently-monitored access for that type of volume is a complex task in any environment. The very nature of mining - with its diversity of locations and operations spread over a single facility - multiplies that complexity."

Three in one - SAS

Aside from managing access for single-site staff populations running into several thousands, mining places higher demands in the areas of safety and security. Vermeulen considers it essential that any access control system must also be equally capable of managing these two functions.

Whether for a mine or its associated refinery, Alan Hilligenn, project manager at Impala Platinum Refineries, fully agrees that a system be multifunctional. According to Hilligenn, "A single, centralised platform that combines control for each of these functions is obviously the way to go in terms of administration, cost and deliverables.

"Between our base metal and precious metal refineries at our facility in Springs, we have over 300 restricted areas managed by a system that controls pre-defined levels of access and security. The same system is also integral to our safety-management. In the event of an emergency, we can account for some 800 people within 10 minutes via card readers installed in Evacuation Account Areas. The system automatically produces exception reports to identify anyone not accounted for and their location."

Progress through technology

According to Vermeulen, technical advances have delivered two key benefits: "In the eighties, the systems were certainly highly efficient, but, in comparison to today they were also highly-priced. Cost-of-capability has fallen dramatically - an IT system that was then R120 000, is costing R25 000 today.

"This means we have been able to extend IT-driven applications into so many more areas within a mine's operations - delivering increased efficiency across a much broader range of activities."

Great strides have also been made in user-recogniton systems. The barium ferrite cards of two decades ago have been superceded by today's proximity cards.

Physical control

Hilligenn acknowledges that the physical control of entry or exit is a vital link in the overall effectiveness of SAS management. Pat Cooke of Turnstar - manufacturers of high endurance products that meet mining's heavy-duty demands - explains that there are two critical components in an industrial turnstile - the base bearing and the rotation mechanism.

"Over the last 13 years we have developed components that completely eliminate failure in these areas. It is by no means uncommon for us to be called in to retrofit these components to other manufacturers' turnstiles that have failed.

"On our turnstiles, the revolving arms are suspended from the top of the steel framework and are controlled by a zero-wear rotation mechanism. Our suspended rotor technology greatly reduces loading on the base bearing which we now manufacture from advanced plastics that are impervious to environmental and operating conditions."

Piet Vermeulen stresses that, "There is no benefit in running technically sophisticated secure-access systems if they are routinely compromised by equipment that is off-line waiting for repair. For high-traffic operations, it is critical that turnstiles do not fail or require any routine maintenance."

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