Electricity and Control January 2021

SAFETY OF PLANT, EQUIPMENT + PEOPLE

At a glance 

In harsh, often dark, and dusty mining environments, the electronic PDS system raises the alert for mobile machine operators and pedestrians, if they are too close to each other.  Booyco Electronics has taken the lead in developing technology that now meets Levels 7, 8, and 9 of the EMESRT safety protocols.  The system for each site is deployed based on the mine’s traffic management plan and the risk assessment related to this.

Assembling components which make up the Booyco PDS system.

Safety between people and vehicles The PDS creates an electromagnetic field around each vehicle or mobile machine fitted with the equipment in the fleet operating at each site. And each miner either carries an electronic pocket tag, or more often now, the tag is in- corporated into the miners’ cap lamps, together with an au- dio buzzer and LED light. Each tag also has an individual identity. More advanced communications can include more sensors on the machinery, and provide greater accuracy, to meet the required safety standards stipulated by the mine. These will affect costs. The system for each site is deployed based on the mine’s traffic management plan and the risk assessment related to this, with the aim to keep machines and people as far apart as practically possible (whether moving at different times or on different paths), except when it comes to maintenance of the machines. Current Booyco PDS technology can effectively detect up to 20 people simultaneously who may be near a moving vehicle. The driver or operator of the vehicle may not be able to see them in the darkness underground, but the Booyco PDS will raise an alert. In each vehicle a BHU – Booyco Host Unit – is installed. This includes a visual display which will indicate to the driver/operator if there are one, two or however many people nearby, and in which direction they are. The full colour visual display and LCD screen provide for green, yellow and red zoning, indicating to the driver the proximity of the people and the respective risk level. At the same time the pedestrians, each with their own electronic tag, are warned that they are close to a moving vehicle, in the green zone, and they should be alert, looking and listening for it. If the pedestrians walk in the wrong direction and closer to the moving vehicle, the risk zoning shifts to yellow for them and for the operator of the vehicle. Depending on the operating environment and the safety specifications for the site (at Level 7, 8, or 9 per EMESRT), the vehicle can be instructed automatically to slow to a crawl speed, which may range from 40 km/h (for surface mines) to as low as 3 km/h (underground). This speed is calculated automatically by the BHU in line with the safety level

Attention to detail in the assembly ensures a quality end product.

EMESRT Safety levels 7, 8, 9 Level 7 – green – is the alert level: alerts mobile machine opera- tors and pedestrians that they are close by and should look out for and/or move away from each other. Level 8 – yellow – is the advisory level: going beyond the alert sig- nals, it includes advisory information, indicating in which direction the people or other vehicles are and advising machine operators to slow down, or stop. Level 9 – red – additionally introduces intervention engineering control measures, which will give instructions to the machine or vehicle’s onboard control system to slow down, or bring it to a safe stop, or if necessary, an emergency stop. applied, parameters configured for each vehicle OEM and type, and the customer’s requirements. The red zone comes into play when the distance between pedestrians and the moving vehicle becomes critical. At sites where Safety Level 9 is in force, if the risk of collision reaches a ‘point of significant risk and danger’, the PDS will automatically instruct the vehicle to bring it to a safe stop, or if need be, an emergency stop. “This goes back to our commitment to Zero Harm,” Smith says. The BHU has the computing power to log all data and events through daily operations, and the company has developed its own Booyco Electronics Asset Management System, BEAMS, which monitors all logged data and events. In maintenance reviews, the data can be shown as a heat map. This will highlight areas of recurring risks, indicating for example, hazards in the traffic management

Electricity + Control JANUARY 2021

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