Ammonium Nitrate – 78 minutes to detonation
It was a clear night on Friday, 5 September 2014. On the Mitchell Highway, locally known as the ‘Matilda Way’ in Outback Queensland, 15 minutes south of Charleville, when at 8:54 pm, a Kenworth prime mover caught fire whilst hauling 52.8 tonnes of ammonium nitrate in 44 bags each weighing 1.2 tonnes. The driver had travelled the route from Gladstone to South Australia for the thirteen months prior, without incident. He told investigators later that the fire initially started in the prime mover, but once flames began to lick the windscreen, he knew that he had to leave the road. As he steered offroad, the truck unfortunately hit a guard rail near the Angellala Creek Road Bridge, causing the B-Double with three loaded trailers to rollover into a dry creek bed.
Fuel tanks ruptured on impact adding diesel to the deadly mix of ammonium nitrate and fire. The countdown to disaster had begun.
The badly injured driver managed to free himself from the burning wreck. A passing motorist stopped to help and was soon joined by a truck driver approaching from the south. The truck driver stayed with the injured man, while the motorist who was a local, left for a nearby farm to contact emergency services at 9:28 pm. There was no phone signal in the area. A second truck driver travelling north also stopped to assist.
Scenes of Crime Investigator, Sergeant Adam Pearson, finished work at 10 pm. He was travelling in a police vehicle when he observed two fire appliances heading out of town, with lights and sirens. He decided to follow to see if he could assist.
Crews not told that the load was ammonium nitrate
The first fire crew arrived from Charleville at 10:03 pm, expecting to find a routine traffic accident. Fire had engulfed the prime mover and first trailer; the injured driver was being attended… then one of the crew made an alarming discovery. Through the intense black of the Outback night, he saw strewn bags of ammonium nitrate.
This vital information had been missed in communications. They had not been informed that the truck carried ammonium nitrate, which is deadly when detonated. On closer inspection, white crystalline balls of prill spilled from where the rig exited the highway, to where it came to rest on the southern bank of the creek bed.
The second fire truck arrived nine minutes later. Shortly after, the first of two explosions occurred. It was a ‘low order’ explosion that caused no structural damage but gave off a ‘fireworks’ effect of white-hot sparks and a ‘pop.’ The first responders needed no further prompting. They were rushing to evacuate the scene when suddenly the second, powerful explosion detonated, generating a massive force that sent out a supersonic shock wave. Massive chunks of debris from the destroyed road bridge and highway, as well as shrapnel from the truck, were hurtled hundreds of metres.
Could anyone possibly survive?
Sergeant Pearson was approaching the crash site when he was knocked unconscious at the wheel of his police vehicle by the impact of the shock wave. Luckily for him, the car came to rest by the side of the road.
Constables Head and Everitt were also approaching in a second police vehicle, a kilometre or so from the scene, when they saw an extraordinary sight. A slim column of fire of rose hundreds of metres into the night sky. It was 10:12 p.m. They were taken aback milliseconds later, when they too were hit by the jolt of the shock wave. Constable Head described it as, ‘a kick in the chest.’
The officers remained stationary in their vehicle while the debris field fell, then continued to the site. On arrival they found what resembled a war zone.
Through all the fire and smoke, Constable Head saw a small light, the type that Queensland Fire & Rescue members have on the side of their helmets. Without concern for their own safety, the two constables raced into the blast zone. When asked by a journalist why they took the risk, Constable Head stated, ‘You just do that sort of thing as a police officer. We all do that sort of thing.’
The Aftermath
The police carried a CODAN radio telephone. It was the only means of communication in the isolated location. They imparted information to start the next phase – the rescue operation.
Officer in Charge of Charleville Police Station, Adrian Rieck, was awoken from his sleep at home by what he had assumed was an earthquake. The blast did, in fact, measure as a seismic event of 2.1 on the Richter scale. The explosion was so powerful (equivalent of 10-15 tonnes of TNT) that it shook the entire township of Charleville, 30 kilometres away. Shortly after, Senior Sergeant Rieck received a phone call from the police station and was advised of the accident and subsequent blast. By the time he arrived on scene, Constables Head and Everitt had extracted all of the injured with the Queensland Ambulance Service. To their amazement, police discovered that there were no fatalities.
How did they survive?
The Senior Sergeant Rieck later explained:
‘We believe possibly the location of the truck… and where it’s exploded… and the construction of the roadway… may have shielded them slightly from the majority of the blast; but there is a significant amount of debris (shrapnel from the truck and concrete from the destroyed road bridge and highway) that has been thrown a significant amount of distance from the initial explosive site.’
Amongst the eight injured, four fire fighters and one policeman were hospitalised. The severity of injury depended on the proximity to the epicentre of the blast, but most experienced hearing problems, burns, cuts from flying debris and internal bruising. The injured truck driver was airlifted to the Royal Brisbane Hospital and placed in an induced coma.
The B-Double carrying the ammonium nitrate disintegrated, two fire trucks were destroyed and a parked truck to the south, and Sergeant Pearson’s police car parked to the north, also sustained considerable damage. Police could not determine the cause of the crash nor why the prime mover caught fire. Molten ammonium nitrate, copper, and aluminium were found at the crash site indicating the heat of the fire was greater than 1000C.
The writer of this blog gratefully thanks Senior Sergeant Rieck for sharing his photography and confirming the order of events at Angellala Creek that night. He added:
‘The blast was the largest peacetime transportation explosion in Australia’s history. It has been the only time that both the Mines Inspectorate and the Transport and Mains Road departments have been able to gather appropriate data as to what happens when ammonium nitrate explodes under these circumstances and has led to the raft of changes for its (safe) transportation.’
Government’s goal – to minimise risk when transporting ammonium nitrate
The Principal Inspector of Explosives for the Department of Natural Resources stated, ‘If the risk of fire is eliminated, controlled, or isolated, then the risk of an explosion is negligible.’ An investigation report by the department notes that all previous incidents worldwide have been on flat deck trailers.
A full copy of the report, including eight recommendations to be implemented for the safe transport of ammonium nitrate, can be found in the link below, as well as a link to a re-enactment video of the incident.
- Re-enactment video: https://youtu.be/horEcWw_KxM
- Abridged Investigation Report by Queensland Government: Investigation Report – Ammonium Nitrate Explosion, Angellala Creek (resources.qld.gov.au)
Queensland Police Museum congratulates the following heroes who received bravery awards for their roles in attending the incident at Angellala Creek.
QPS Valour Award: Senior Constable Mark Patrick Everitt, Senior Constable Kenric Head
Bravery Medal: Senior Constable Mark Patrick Everitt, Senior Constable Kenric Head and Michael Bradley Hadj
Star of Courage: Peter Robert Hackwood, Clinten Thomas McCarthy, Jake Paul Sullivan, and Nathan James Thompson
Commendation for Brave Conduct: Senior Sergeant Adrian Paul Rieck and Liam Colin Walsh
Group Bravery Citation: Inspector Stephen Edwin Kersley, Senior Sergeant Adrian Paul Rieck, Senior Constable Mark Patrick Everitt, Senior Constable Kenric Robert Head, Senior Constable Juliet Heather McGrath, Constable Logan Tristan De Costa; John Norman GILBERT, Peter Robert Hackwood; Michael Bradley Hadj, Clinten Thomas McCarthy, Jake Paul Sullivan, Nathan James Thompson, and Liam Colin Walsh.
This story was inspired by Les Bardwell’s story ‘Ammonium Nitrate,’ from his anthology of works titled ‘No Stone Unturned.’ It was researched and written by Museum Assistant Debra Austin using the best archival resources available.
The Police Museum is open 9am to 4pm Monday to Thursday and 10am to 3pm on the last Sunday of the month (Feb-Nov) and is located on the Ground Floor of Police Headquarters at 200 Roma Street, Brisbane.
Contact: E: museum@police.qld.gov.au
“FROM the VAULT: Boom! Part 2 – Ammonium Nitrate – 78 Minutes to detonation” by the Queensland Police Service is licensed under a Creative Commons Attribution (BY) 2.5 Australia Licence. Permissions may be available beyond the scope of this licence. http://creativecommons.org/licenses/by/2.5/au/legalcode