Security at manganese and iron-ore miner Assmang’s Black Rock mine, in the Northern Cape, has been improved in the past 18 months since moving from a radio-based alarm monitoring and communications system, to Devtron’s cloud-based Circuit Master solution.

Assmang mines manganese ore at the Black Rock mining complex situated in the Kalahari Manganese Field, which contains around 80% of the world’s known high-grade manganese resource.

In total, 3.6-million tonnes of iron and manganese ore a year are excavated and produced across Black Rock’s three separate mine shafts, thereby requiring high security, given its location across multiple sites and range of activities. These activities include earthmoving, the transportation of ore, on- and off-loading, collection of mining equipment and other on-site support functions.

Supplying security services at the mine, Thorburn Security Solutions senior technician Raynier Vorster explains that, over the past five years, the mine has been expanding its exploration, resulting in its overall area of operations increasing exponentially.

“During 2019, the increased activity resulted in a number of security challenges and it became clear that there were various shortfalls in the existing security system that would need to be addressed to beef up security.”

The new system, which was installed within three months, has greatly enhanced Thorburn Security Solutions’ ability to provide effective security at the mine, says Vorster.

Moving from a radio network to Global System for Mobile Communications means that when one mobile network is down, the mine can immediately switch to another. Communications can be data-based, which eliminates errors that typically arise from radio interference, especially given the large size of the mine and its multiple operations.

A key issue related to the mine’s radio-based alarm signalling system, which resulted in erratic communications and had limited capacity for user notifications and control room assistance in the event of an alarm.

“The unstable nature of radio communications severely undermined our ability to respond to security breaches,” he explains, adding that it sometimes took up to 15 minutes before signals reached the control room, and when they did, the radio interference often made them unclear.

Further, the fence also needed upgrading and the old energisers employed had limited capacity and functions. In addition, there were no zone-specific alarm notifications, and the notification panel could provide no assistance on possible actions that could be taken.

To address these concerns, Nemtek, which supplied the mine’s 60 km fence and with a long-standing strategic partnership with Devtron, requested the assistance of Devtron to determine the mine’s requirements.

Devtron’s Circuit Master solution enables a digital, livestreaming electric fence monitoring system that can be simultaneously viewed by multiple sites with the Circuit Master system being centred on a third-generation Devnet24 modem.

Based on the same robust technology as used in the banking industry, it collects all the perimeter and equipment data and makes it possible for anyone connected to use the system to monitor and enhance the effectiveness of the fence on a 24/7 basis.

“Perhaps the most important benefit is that any alarm signals from 145 alarms, situated right around the mine, are now received in the control room within seconds, as opposed to minutes,” says Vorster.

“We can pinpoint the exact unit and zone affected, so a technician can be rapidly dispatched to fix it. Any assistance they require is available from the control room, a laptop or cell phone,” he notes.

Power was sourced from a solar unit next to each energiser, which saved costs and reduced the mines dependency on electricity. By attaching the sensors to the solar panels, they are also able to be monitored by the Devtron system.

“Since it was installed 18 months ago, the system has remained stable and can operate in all weather conditions,” concludes Vorster.