Spotlight Feature Articles MINE SAFETY - Page 4

MINE SAFETY Booyco Electronics Engineer and Developer, Frank Schommer, said: “Based on a high frequency wave transmission, the new VDS technology has been developed to comply with the latest safety regulations for moving vehicles on mines.” While these high frequencies do not penetrate rock in underground mining environments like low frequencies can, they are able to detect other vehicles at a greater distance, according to Booyco. “Like the pedestrian PDS, the Booyco VDS’ functionality is based on different ‘zones’ within the radio field around each vehicle that is created by a transmitter; the distance of each zone from the vehicle can be defined by the customer, depending on their actual conditions and specific vehicles on site.” Schommer gave an example: “The system can be set so that it delivers a warning to the operators at a distance of 50 m. If no action is taken after that warning, and the distance between the vehicles is reduced, then a second zone is entered, and a command is generated for the operator to reduce speed. If speed is not reduced and the vehicles continue to get closer to each other, an intervention is triggered by the system to slow the vehicles down.” The accuracy of the system ensures there is enough reaction time after warnings are given for the operator to act, reducing the possibility of a collision, according to Booyco. While the system caters for larger vehicles with longer distances between them – such as surface mining load and haul operations – it is also applicable underground as it can measure long distances between machines through tunnels, according to Booyco. Booyco Electronics’ PDS system – based on very low frequency wave transmission – can, meanwhile, penetrate tunnel sidewalls underground, allowing the detection of pedestrians out of sight around a corner, but over shorter distances. This is why Schommer recommends using the VDS and PDS in tandem underground. “Combining these technologies allows mines to improve safety between vehicles – where the distances to be measured are longer – as well as between vehicles and pedestrians – where it is important to detect workers who are closer but not visible to the operators,” he said. Australia first Strata Worldwide recently achieved an Australia- first application of proximity detection on underground shuttle cars in a Queensland coal mine with one of the world’s leading mining companies. As a proactive safety measure, the miner International Mining | OCTOBER 2019 The E-A-Rfit Dual-Ear Validation System from 3M can test the effectiveness of ear plugs or muffs while they are being worn, giving accurate results in seconds, according to the company undertook extensive research on Strata’s HazardAvert PDS technology, with both the client and Strata Worldwide working together to test and trial the technology in underground coal mining environments. The miner’s primary goal was to reduce the potential risks to people working in close proximity to mobile equipment. HazardAvert proximity detection field generators, installed on equipment, form electromagnetic (EM) warning and danger zones around the machinery, according to Strata Worldwide. These zones are detected by the HazardAvert Personal Alarm Devices installed on miner cap lamps or worn on the miners’ belt. When the zones are breached, either by a miner entering the zone or by the shuttle car approaching a miner, the system alarms and alerts both parties. To overcome situations where reaction time is limited, the system can be interfaced into the controls of the equipment to automatically slow or stop the machinery, the company added. Strata’s Michaud said the company’s patented EM technology is not impacted by the coal seam, mining curtains or other obstacles that might block line of sight. The EM technology creates a very stable and precise zone around the machine, according to Michaud. In many operating scenarios, the operator must stand just a meter or so away from the machine in order for the system to pick up the interference. He added: “The HazardAvert EM system is able to create customs zones with cm accuracy. The precise and consistent zones reduce the nuisance alarms which increases operator acceptance of the technology.” Mining companies also benefit from the ability to maintain the PDS equipment on their own, with the modular design enabling them to switch out components without the need to call on Strata personnel. Lastly, the performance of HazardAvert is not impacted by the number of people around the vehicle, incurring no additional performance latency whether there are five or 100 people around the machine, according to Michaud. “This is critical for areas where there is a large number of machines and people in a confined space,” he said, adding that the HazardAvert system was the first to achieve an EMESRT Level 9 CAS performance rating. PDS has been used on shuttle cars in the US and South Africa in line with the aforementioned regulations, but this mentioned Queensland installation is the first approved system to be introduced in a coal production scenario in the country, according to Strata. At the recent AIMEX 2019 event, in Sydney, Australia, Paul Mullins, Global Product Manager for Strata, provided IM with some more detail on this recent project win, which was the culmination of two years of due diligence work at the mine. Over this period, underground shuttle cars were fitted with the required proximity detection technology as they were brought in for overhaul, allowing the mine to keep up with its coal production targets. The physical installation of the PDS was undertaken at Komatsu’s Rockhampton facility, in Queensland. Komatsu worked with both Strata and representatives from the mine operation to re-design the control system of the shuttle cars to ensure the system effectively integrated with the machine, according to Komatsu. “In doing so, Komatsu were able to ensure the shuttle car automatically functioned in the manner requested by the mine operation, in the event the PDS alerted the presence of mine personnel,” Komatsu said. The machine was designed to slow down when miner personnel entered a ‘warning zone’ and stop in the event mine personnel became too close to the shuttle car and entered the ‘stop’ zone.