The Australian Standard for Lightning Protection, AS 1768:2021, outlines the necessary specifications for safeguarding various structures and systems from lightning strikes. It outlines criteria for designing, installing, maintaining, and testing lightning protection systems for common structures and the electrical and electronic systems within them ensuring the protection of individuals and property from lightning-related risks. It was recently revised in 2021 to align closer to the global IEC (International Electrotechnical Commission) standards which assist in compatibility and environmental safety in regards to product development and performance.
In an effort to minimise the potential for damage or injuries caused by lightning, the standards incorporate a risk assessment tool that evaluates the calculated risk and compares it to a tolerable risk level, recognising that protective measures may be warranted regardless of the risk assessment's outcome. One of the primary aspects of the risk assessment process involves the utilisation of the average annual lightning ground flash density (Ng), which is derived from a map provided by the Australian Bureau of Meteorology (BoM) and featured within the standard. This map is accessible on the BoM website and serves as a broad indicator of lightning risk across various regions in Australia, allowing you to view your rating and judge your own risks.
The lightning group strike density represents the amount of ground flashes (lightning strikes) that occur per square kilometre each year. For example, If an area is denoted with an Ng value of 2, there is an average annual expectation of 2 ground flashes in each square kilometre. Typically, it's advisable for areas with an Ng value of 2 or higher to contemplate implementing a lightning protection system, equipotential bonding, and surge protection device installation.
Northern parts of Western Australia have some of the worst lightning-ground flash density ratings in the country, with the highest being Ng 12 near Kalumburu, these elevated Ng ratings underscore the critical need for vigilant lightning safety measures in these areas.
Protecting Your Assets With a Fabric Dome Shelter
Exposure to lightning during a thunderstorm poses a significant and potentially life-threatening risk, especially in regions with higher Ng ratings. While experts emphasise that nothing can provide absolute, 100% lightning protection, there exist numerous strategies to substantially enhance safety when seeking refuge indoors is not a viable option. This situation often arises in remote construction sites or expansive mining operations, where shelter options are limited.
One practical solution is the utilisation of fabric dome shelters, like the ones at Allshelter, which serve multiple purposes, such as providing workshop spaces, housing vehicles, and material storage areas. Beyond these primary functions, fabric shelters offer a critical advantage in protecting individuals and equipment from unpredictable and often perilous weather conditions, including lightning strikes. These shelters act as a protective barrier, significantly reducing the risk of lightning exposure.
The steel framing of these fabric shelters plays a pivotal role in conducting the electrical charge safely to the ground, thereby minimising the risk to those inside. Simultaneously, the non-conductive polyethylene fabric used in their construction assists in dissipating the electrical charge, further enhancing the shelter's capacity to mitigate lightning-related hazards. In scenarios where seeking indoor safety is unfeasible, these fabric shelters can prove to be an essential element in safeguarding lives and valuable equipment against the potentially devastating effects of lightning strikes.
