Coal Inspectorate | Alert | No.462 V 1 | 04 November 2025

Court ruling: lightning hazards

Summary

• Lightning is a risk to workers across the resources sector, and workers at surface mines and quarries are particularly exposed to risk of injury from lightning strikes.
• Operating non-autonomous heavy mobile equipment (HME) when lightning is very close to, or at, site is not safe (even with nitrogen-filled tyres) a recent court decision has confirmed.
• Ahead of storm season, we urge sites to review their Trigger Action Response Plans (TARPs) and consider the learnings outlined below to keep workers as safe as possible during lightning events.

Issue Explained

• Lightning strikes at mines and quarries during storm season are relatively common and can affect heavy mobile equipment (HME).
• Lightning can strike equipment or the ground directly, cause tyre explosions in vehicles with air-filled tyres (due to tyre pyrolysis) or travel through conductive parts of vehicles and buildings, electrocuting workers.
  • Filling HME tyres with greater than 95% nitrogen minimises the risk of tyre explosions due to pyrolysis.
• The most recent lighting event causing injury in Australia occurred in Western Australia in January. Six workers required medical treatment after a lightning strike caused a tyre explosion in a dump truck.
• Recently, the Court of Appeal of Queensland confirmed a decision from the Industrial Court, backed by expert advice, which gave a clearer direction to surface mines on what constitutes unacceptable risk in operating HME during severe lighting events. RSHQ welcomes the courts’ decisions.
  • The case arose from an appeal against a directive issued by RSHQ Chief Inspector of Coal Mines Jacques le Roux in October 2023 to stop a major mine from operating during lightning activity in storm season.
  • The mine’s TARP prescribed actions to be taken in the event of lightning when triggers (levels) are reached. Level 1 is activated when lightning is within 60 to 30km of the mine, Level 2 when it is within 30 to 16km, and Level 3 when it is less than 16km from mine.
  • The surface coal mine in Central Queensland changed its operations such that heavy mobile equipment (HME) could continue to operate during Level 3 conditions under its trigger action response plans (TARP) for lightning - when lightning is detected less than 16km away - because tyres of the HME were filled with 95% nitrogen.
  • The court heard evidence during the proceedings from two lightning experts and two experts in materials engineering (as to the effect of nitrogen fill in tyres).
• The court found that operating non-autonomous HME when lightning was within 16km of the site (in Level 3 lightning conditions) presented an unacceptable safety risk, even with nitrogen-filled tyres, due to workers being in contact with pedals and other items within the cabin which have low levels of conductivity resistance.
• Having considered the evidence of the experts, the court also made the following findings:
  • Lightning strikes at the mine, and on HMEs, during storm season are relatively common.
  • There is a risk that if a HME is operated in a Level 3 event and the tyres are not filled with nitrogen to the point of 95%, the tyres will explode causing the vehicle to become uncontrollable, creating unacceptable risk to the safety of workers.
  • Filling tyres with nitrogen might reduce one risk of lightning strikes (exploding tyres) but not all risks.
  • HME have a Faraday cage effect, so that the energy of a lightning strike which hits them is disbursed across the surface of the vehicle. This gives partial protection to those inside the HME but, given the construction of HME, they do not act as a true Farraday cage. There are lines of conductivity into different HME, and it is not possible to identify all of them.
  • Many of the controls (pedals, levers etc) within an HME have low levels of resistance to conductivity. The prospect of a coal mine worker touching a metal surface within the HME is greater if the worker is busy within the cabin driving and otherwise operating the HME than if it is parked up.
  • The risk to the safety of a coal mine worker operating HME at the mine in Level 3 conditions may reach unacceptable levels. There is a possibility of death or injury.
  • Under this mine’s relevant TARPs, in Level 3 conditions, the risk to a coal mine worker in a parked-up (nitrogen tyre filled) HME does not reach unacceptable levels because controls with low levels of conductivity resistance will not need to be operated. Education of workers and protocols can manage the discipline of workers not to touch metal surfaces when parked up.
  • For this mine, the TARP should operate so that operations (in nitrogen filled tyre vehicles) can continue where lightning strikes occur within 16-30km of the mine, but the vehicles must be parked up, and the workers should remain in the vehicles where lightning strikes are within 16km of the mine, until those conditions have abated.
• The court made orders consistent with the findings, effectively varying the RSHQ directive to allow continued operations in HME with nitrogen filled tyres when lightning is 16-30km from site (Level 2), but requiring vehicles to park up and stop operating if lighting is within 16km (Level 3).
• RSHQ Inspectors will continue to audit the Safety and Health Management Systems (SHMS) and TARPs associated with lightning and extreme weather throughout storm season to confirm mines are achieving an acceptable level of risk for workers during lightning events.

Learnings

• The safest place for workers during a lightning event is in a secure building with lightning protection.
• Sites are encouraged to use nitrogen-filled tyres given the increase in safety this provides.
  • Surface mines operating HME with nitrogen filled tyres must ensure there are adequate processes in place to ensure the tyres maintain greater than 95% nitrogen levels.
• Workers should never be in HME without nitrogen filled tyres when lightning strikes are within 16km.
• Mines that do not operate HME with nitrogen filled tyres should ensure the safe transition of workers to a secure building before lightning approaches within 30km of the mine (Level 2).
• Given the risk of workers transiting from the cabin of HME to a secure building during a severe lightning event, remaining within the cabin of an HME with nitrogen filled tyres, but not operating the vehicle, represents a potential way of managing risk to workers to an acceptable level.
  • Worker safety in these conditions is dependent on adequate policies and education to ensure the safe parking up of vehicles, and that workers wear appropriate safety equipment (rubber sole work boots) and do not touch metal surfaces.
  • Mines must educate workers not to touch metal surfaces during Level 3 events, to wear insulated boots, and to follow strict protocols when remaining in HMEs with nitrogen-filled tyres.
  • However, RSHQ’s view is that it is preferable for workers to move to a safe building before Level 3 is reached even if tyres are nitrogen filled to avoid having to remain in the HME.
• Trigger Action Response Plans (TARPs) vary across the mining industry, especially the distance thresholds for Level 3 lightning alerts which can range from 5-30km.
  • RSHQ strongly recommends all SSEs review TARP parameters to ensure distances are based on appropriate expert advice to ensure risk to workers is managed to an acceptable level.
• Non-autonomous HME must never be operated where lightning strikes occur within 16km of the mine (Level 3).
• SSEs should also carefully consider the safest park up locations during lightning events in conditions where parking up is appropriate.
  • For example, parking at locations at a lower elevation on the mine is likely to be safer than more elevated sites. Also, areas that have lightning protection installed will offer an increased level of safety for workers required to transfer from an HME to a safe building.

References and further information

• BM Alliance Coal Operations Pty Ltd v le Roux (No 2) [2024] ICQ 20