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Christian Fimpler and Frank Kathmann, Eaton, explain how recent technological advances are making communicating underground more efficient and effective.
onnectivity and the human-machine interfacing are concepts being embraced across many industries – and with good reason. The ability to share information, analyse data and respond in real time to fault signals or maintenance requirements, is key to optimising production and driving down costs. Indeed, in industries such as mining and tunnelling, the ability to co-ordinate humans and machines, as well as relay essential data about what is happening in real time back to the surface, is not only a matter of optimising production, it can be life-critical.
Designing a hazardous area communication system While there is no doubt that communications between the surface and those below ground, between both machines and humans, are essential functions, there are a number of challenges to overcome when designing a hazardous area communication system. Firstly, there are the natural environmental risks associated with working underground. Damp, dust, and potentially explosive atmospheres are not conducive to the introduction of sophisticated electronic communications networks. Secondly, the nature of drilling, mining, and tunnelling operations add other environmental phenomena that can be detrimental, such as high levels of vibration and noise. It is therefore important to ensure that essential messages can be relayed without interference, and that they cannot be ‘missed’ by the intended recipient. A third consideration is the nature of industry. The underground working environment is highly mechanised, and
the scale of the equipment involved is colossal. For example, vertical shaft drilling machines – commonly used for sinking sewers, mine, and ventilation shafts – have a typical diameter of between 4.5 – 9 m. These machines generate a lot of heat and vibration in very confined spaces. Communications devices therefore need to cope with wide variations in temperature and high levels of electronic interference. Now the environmental conditions have been summarised, the human element needs to be considered. Although far fewer people work below ground now than in previous decades, they are subject to new safety challenges. Proximity to large scale and remotely-controlled machinery is one risk, but also, with fewer personnel underground, workers are now working at more remote distances from both each other and help, should it be needed. It is not unusual for mines and tunnels to stretch for hundreds of kilometres underground, and people are still required to penetrate these vast, manmade caverns to service and repair equipment. The need for reliable and timely communication is growing, rather than diminishing, as operations become more automated than ever.
Current communications The complexities of communicating underground have led to a number of solutions being developed over time. For example, communications systems using public address and voice alarm (PA/VA) technology have evolved to relay voice messages and audible warnings; automation systems exist to enable control and co-ordination of machinery and equipment; and fixed point telephones provide emergency call points for personnel.
global mining review // September 2021
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