IMPLEMENTING RECOMMENDATIONS FROM THE ANGELLALA CREEK AMMONIUM NITRATE VEHICLE EXPLOSION Chris Donovan Senior Inspector of Explosives Explosives Inspectorate, Department of Natural Resources and Mines (Qld)
INTRODUCTION Role of Explosives Inspectorate Incident outline Investigation outcomes Implementation of the recommendations Impact for fire response
ROLE OF EXPLOSIVES INSPECTORATE VISION Our community Safe and Secure from Explosives MISSION To protect our Community from the Adverse Impacts of Explosives Handling Manufacture Transport Use Possession Import/ Export Storage Disposal
EXPLOSIVES INCIDENT ROLE Usual role as advice agency to Fire Services/Police/Other Angellala Creek Police vehicle crash Fire services Hazmat Explosives Inspectorate explosion investigation
ANGELLALA CREEK INCIDENT OVERVIEW
MITCHELL HIGHWAY BEFORE
MITCHELL HIGHWAY AFTER
INCIDENT SITE
MAJOR INVESTIGATION FINDINGS The ammonium nitrate was within specification and classified as UN1942 The vehicle involved in the accident was mechanically sound and regularly maintained The vehicle contained a large amount of combustible material The crash led to a spill of fuel across the site Some ammonium nitrate was contaminated with diesel fuel and metals An arc blast event has occurred in the power circuit
CAUSE OF FIRE The cause of the vehicle fire could not be definitively determined. Based on analysis the following probable scenarios are proposed: Fuel loss from damaged tanks contacted hot engine exhaust and ignited, Fuel loss from damaged tanks ignited from an electrical arc in the damaged power circuit.
CAUSE OF FIRST EXPLOSION The cause of the first explosion could not be determined. The analysis of evidence gave the following possible scenarios: A pressurised piece of equipment (e.g. tyre or air tank) has ruptured from the fire A thermal explosion from heating and decomposition of ammonium nitrate Molten aluminium has contacted water or molten ammonium nitrate causing a violent reaction
CAUSE OF SECOND EXPLOSION The cause of the second explosion could not be determined. Explosion was estimated to be between 10 15 tonnes of TNT. The second explosion caused significant destruction to nearby infrastructure, vehicles and blast injuries to people nearby. People 50 metres away experienced blast overpressure less than 70kPa (100% fatality in the open) The creeks banks and the bridge decks provided some protection from overpressure and shrapnel to persons. Further detailed post blast analysis required
INVESTIGATION RECOMMENDATIONS Vehicle design Develop appropriate design criteria for vehicles transporting ammonium nitrate Load protection by steel vertical and horizontal firescreens Reduce combustible material in load area Segregate fuels and sources of ignition, protect wiring circuits. Incident Response Early initial incident notification and load identification. Appropriate Hazchem code labelling Review hazard communication and pre-planning Updates to HB76 Guide 50/51 (new ERG drafted) Further research Interaction of AN with molten metals
IMPLEMENTATION PROCESS Explosives Safety Alert 86 Ammonium nitrate explodes during transport incident Hazchem code for ammonium nitrate of UN 1942 changed from 1Z to 1Y to consider the violent risk of an explosion National Informal Working Party (IWP) to review vehicle design for ammonium nitrate transport (meeting 9 May 2017) National Transport Commission inclusion of water/foam fire systems and extinguishers Release of report brief and video (DNRM website soon)
INFORMAL WORKING PARTY IWP for AN vehicle design consists of: Dangerous Goods and explosives transport regulators AFAC AN transporters AN manufacturers AN transport experts Scope: review of the design of ammonium nitrate vehicles with a focus on fire mitigation and load protection.
AMMONIUM NITRATE VEHICLE DESIGN Key design considerations: Review location of batteries and electrical system to fuel Reduce fuel load on vehicle (diesel, combustibles) Rollover and manual battery isolation Fire screens Fire/heat detection system displayed in the cabin Fire suppression system in the engine bay, turbo and exhaust Black box for video, communications, GPS and vehicle systems Improve communication from vehicle to alert incident (loss of signal, deviation from route, G-Force, rollover etc.) Focus on fire response solutions Questions?
ADDITIONAL FOAM AND FIRE EXTINGUISHERS NTC Maintenance Group meeting 23 March 2017 agreed a high level review of foam/water and fire extinguishers for dangerous goods vehicles based on Qld proposal Issues: High proportion of vehicle fires due to brake/bearing/tyre to load No water/foam on vehicles to deal with these types of fires EPG (AS1678.0.0.001) and ERG (HB76) require copious amounts of water for small fire if AN load not involved Driver waits for fire services to arrive, increases risk of major fire/explosion
WATER-FOAM FIRE FIGHTING SYSTEM
QUITFIRE SYSTEM DEMO.
WHEEL MONITORING Wheel monitors for pressure and temperature increases that alerts the driver via in cab display Can check wheel issues before overheating and tyre pyrolysis begins If used as an alert in conjunction with water/foam system, can easily resolve tyre issue without a fire. Currently some ammonium nitrate and explosives transporters are trialling technology
CHANGES TO EMERGENCY RESPONSE GUIDE QFES made recommendations to update HB76 Guide 50/51 for response to an ammonium nitrate incident Provided new wording to all fire services in Qld to update HB76. (Available for other jurisdictions) Current draft version of new ERG (modelled on CANUTEC) has incorporated these changes Main focus on increasing evacuation distances for AN fire (Class 1) Limiting the decision making process of small or large fire and when to fight fire or evacuate
QUESTIONS