Ammonium Nitrate – Created for good, but deadly when detonated
In the early 20th century, scientists were concerned about population forecasts for the coming millennia and the impending problem of growing enough food to feed the world. Nitrogen, which is crucial to plant growth, was the focus of their research. Nitrogen is found in a limited supply in nature as a mineral, but it is abundant in the gaseous state and makes up approximately 78% of the Earth’s atmosphere.
In 1908, a German chemist at the University of Karlsruhe, Fritz Haber, discovered how to chemically synthesise ammonia from nitrogen (from the air) and hydrogen (from natural gas) using iron (as a catalyst) whilst under pressure and in very high temperatures, to form a compound called ammonium nitrate, which is a white crystalline substance. This had long been deemed impossible because of the inert nature of nitrogen gas.
His brother-in-law, Carl Bosch, industrialised production of the compound in 1913, in what would become known as the ‘Haber-Bosch’ process. The ability to use the abundant reserves of nitrogen in nature to produce fertiliser, and increase crop yields, is considered one of the most important discoveries of the modern age. They individually won a Nobel prize in Chemistry in 1918 and 1931 respectively, for their contribution to science, and boosting production of the world’s food supply, though Haber, a German patriot, would later tarnish his reputation by acquiring an infamous title:
‘The father of chemical warfare.’
An ignoble use of genius
As Director of the Kaiser Wilhelm Institute for Physical Chemistry and Electrochemistry in 1914, Fritz Haber placed his team at the service of the German War Office. The goal was to weaponise gas, despite Hague Convention agreements that prohibited the use of chemical agents in battle. In practice, he had difficulty finding army commanders to test his weapons. Many considered it ‘unchivalrous.’ Regardless, Haber swapped his lab coat for a German captain’s uniform in 1915 and went to the Western Front where he instructed the German army on how to deploy the gas in prevailing winds. On the morning of Thursday, April 22nd, 168 tonnes of chlorine gas was released over the trenches near Ypres, Belgium. Within minutes, over 5,000 men died from asphyxiation. A Canadian survivor described the horror:
‘(…it was) an equivalent death to drowning only on dry land. The effects are there, a splitting headache and terrific thirst (to drink water is instant death), a knife edge of pain in the lungs and the coughing up of a greenish froth off the stomach and the lungs, ending finally in insensibility and death.’ He added, ‘It is a fiendish death to die.’
As they left the trenches vomiting and choking, a five-kilometre gap was created in the defences, but the Germans failed to take the advantage. Allied forces quickly filled the void using hastily improvised gas masks made from urine-soaked handkerchiefs that neutralised the chlorine.
Harmless… except when detonated
Well over 100 years later, ammonium nitrate continues to be uses as a fertiliser to boost production of over half the world’s food supply. A prilled form (mixed with 6% fuel oil) is used as an oxidiser in blasting for mining, quarrying and civil construction. Both forms are considered relatively ‘insensitive’ and safe for transport – except when contaminated with fuels, organic matter, or other chemicals and/or exposed to extreme heat or fire, or a combination of any of these, as well as being stressed by heat and pressure… or deliberately detonated. Ammonium nitrate then becomes a powerfully explosive blasting agent.
Accidental ammonium nitrate explosions have killed thousands worldwide. On 4 August 2020, 2,500 tons of ammonium nitrate being stored in a warehouse in the Port of Beirut exploded killing 218 people. A powerful, supersonic shock wave generated, causing catastrophic damage. Most of the victims died instantly and a further 5000 people were injured. The explosion is categorised as the third worst urban explosion of all time after the Hiroshima and Nagasaki nuclear bombings at the end of World War Two. It created a 140-metre-wide crater and left over 300,000 people homeless.
Many countries are now phasing out use of ammonium nitrate because of the potential for its misuse. In Oslo in 2011, Norwegian terrorist, Anders Breivik, exploded a car bomb made from ammonium nitrate, as a decoy. This lured emergency services as he anticipated, while he proceeded to Utoya Island where his true mission lay – the massacre of students on a Youth Camp. In all, 77 innocent people died that day.
Timothy McVeigh killed 168 people when he bombed a federal building in Oklahoma, USA, on 19 April 1995, by detonating a van full of ammonium nitrate.
Outback deaths – 1972
Two fiery truck crashes involving the transportation of ammonium nitrate, and resultant detonation of the load, have occurred in recent Queensland history. The first occurred on the evening of 30 August 1972, when a load of 510 bags of ammonium nitrate, each weighing 80 pounds (36.2 kilograms), was being transported to a mine in the Goonyella coalfields. The truck crashed and caught fire, 100 kilometres from Taroom in Central Queensland, 480 kilometres north-west of Brisbane. The incident resulted in an explosion that killed three men instantly – the truck driver, 25-year-old Ronald Holzberger, and two brothers from nearby Stonecroft Station; 20-year-old Evan Becker and 18-year-old Douglas Becker, who raced their motorcycle to the crash site to give assistance.
Around midday the next day, the lead investigator, Detective Inspector Les Bardwell from the Brisbane CIB, travelled by light aircraft to the scene with the Brisbane-based Inspector of Explosives from the Department of Natural Resources, and a representative from the chemical manufacturer. He later declared that he was ‘absolutely aghast’ by what he discovered. He had expected to find the burnt out remains of the vehicle, but there was nothing. The prime mover and trailer had completely disintegrated and all that remained was a crater, measuring 9 metres x 12 metres with a maximum depth of 1.2 metres.
The engine block of the diesel prime mover was the only readily recognisable portion of the vehicle located in the immediate vicinity. Truck parts were later found up to 1.6 kilometres away. The massive turntable that connected the prime mover to the trailer was found 360 metres from the epicentre of the blast, badly distorted. Leading downhill from the site was a solidified lava-like run of molten ammonium nitrate: one metre wide, 114 metres long, and up to 15 cm in depth.
A memorial plaque was erected on 30 March 2013 on the unsealed Fitzroy Development Road, approximately 90 kilometres north of Taroom, near Stonecroft Station. The bull-bar from the International Transtar prime mover, which has been moved to its present site, stands as a silent witness. It was found in trees, 200 metres north of the crater. The absence of damage to foliage suggests that it had been blown hundreds of feet into the air before falling vertically.
Could this type of incident happen again?
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 1 – Ammonium Nitrate Created for good, but deadly when detonated” 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