The Port of Beirut explosion: A timely reminder

The devastating explosion in the Port of Beirut on August 4 seems, if possible, was made worse by the video images captured by ordinary citizens and fishermen from the city. A normal day, disrupted by a dockside fire, then a catastrophic detonation, complete with a view of the supersonic shockwave as it expanded across the city.

As the political and social ramifications reverberate across the Lebanon, a country still not at peace with itself and suffering from the decades long civil war, the incident is a timely reminder that dangerous substances can be found in even the most innocuous places, and only good fortune and luck (and sometimes good legislation, effectively enforced) can prevent more of these tragedies occurring.

The explosion in the Port of Beirut involved around 2,700 tonnes of ammonium nitrate that had been seized along with the ship, the Moldovan-flagged MV Rhosus, which was deemed unseaworthy by the port state control office and forbidden to sail in September 2013. The ship, which had been transporting the fertiliser to Mozambique from Georgia for use as an explosive, was abandoned after the owner went bankrupt and the cargo put into warehouse 12 in 2014. Despite several attempts to have the ammonium nitrate disposed of (it was recognised that there was a serious danger that the climate would have an effect on the materials), the ammonium nitrate was left in situ.


“There’s something wrong here; there is a crazy sound and a huge fire”


When the fire broke out around 17:40 (local time) on August 4, warehouse 12, adjacent to the port’s grain silos, was not only storing the ammonium nitrate but also a quantity of fireworks. At 17:55, nine firefighters and a paramedic were mobilised to the fire, having been told the fire was in a warehouse with the contents being reported as being “just fireworks”. The fire crew in attendance immediately suspected things were not as they expected and reported to fire dispatch centre: “There’s something wrong here; there is a crazy sound and a huge fire” and asked for reinforcements.

According to Al Jazeera, additional pumps were alerted and as the first driver slammed the appliance door shut the main detonation occurred. An earlier explosion at around 18:07 ignited the fireworks and caused flashes of white light among the orange smoke and fumes, typical of the nitrogen oxides given off during thermal decomposition. The main detonation, about 35 seconds after the first, was recorded as being equivalent to a local magnitude earthquake at 4.5 on the Richter scale by the Jordanian seismological observatory (but around 3.3 from other surveys).

The 2,700 tonnes of ammonium nitrate was the equivalent of around 1,100 tons of TNT (tri-nitro-toluene). The nuclear bomb dropped on Hiroshima was equivalent to approximately 15,000 tons of TNT. The explosion left a crater 140m in diameter and nearly 45m deep. The grain silos were destroyed with approximately 15,000 tonnes of wheat rendered inedible which means that the country was now left with less than 30-days’ supply of grain, once again leading to Lebanon becoming a crisis point in the Middle East. The cost of damage has been put at around £15 billion with only £3 billion’s worth being insured. Five hospitals have been destroyed or badly damaged.

At least 178 people died with 6,000 injured and 300,000 people left homeless. The first attending paramedic and firefighters were all killed in the main detonation and their vehicles destroyed beyond recognition. They remain amongst the 30 or so victims still missing. According to Lebanese sources, the fire was caused by welders working on the door to the warehouse.

explosion at Oppau

The aftermath of the explosion at Appau


Ammonium Nitrate

The substance at the centre of the disaster, ammonium nitrate (AN), has a chequered history: in 1911, the recently discovered Haber process allowed Germany to produce large volumes of AN without requiring the importation of chemicals. Ammonium nitrate was used as an explosive in the First World War and its production became extensive.

There had been several accidental explosions where AN was at least part of the problem. In the UK, there have been several serious explosions including the “Great Explosion” at Faversham, Kent, the home of the British explosives industry since the 17th century. On Sunday, April 2, 1916 a fire amongst some empty sacking materials ignited around 200 tonnes of TNT and AN (which was to be combined to produce Amatol – a 40/60 per cent mixture of AN and TNT respectively) leading to the detonation of what has been described as the “worst ever in the history of the UK explosives industry” in which 115 workers were killed including all of the works fire brigade. Fortunately, because it was a Sunday, there was only a reduced workforce and no “Canary Girls” (female workers whose skin was bleached yellow by the picric acid in explosives) died in the disaster. It was with relief that an additional 3,000 tons of explosives in the next shed did not detonate.

In Germany, the home of the Haber process, research had predicted that mixtures of ammonium sulphate and nitrates with less than 60 per cent nitrates would not explode. The Badische Anilin und Soda Fabrik (BASF) plant in Oppau, (now part of Ludwigshafen, Germany) used a 50/50 mixture (presumed safe to be stored in up to 50,000 tonne lots) which was believed to be stable. It was supposed to be so stable that dynamite was used to loosen compacted ammonium nitrate and sulphate in the bottom of silos. On September 21, 1921 at 07:32 4,500 tonnes of the mixture in a 20-metre-high tower silo detonated in two explosions, half a second apart. Changes made to the process of manufacture a few months earlier lowered the humidity level in the AN to two per cent from three to four per cent and a changed crystalline structure increased the overall density.

Previous incidents, including at Kreiwald (also 1921) involving AN provided an opportunity to learn lessons but these were not immediately considered or promoted. The cause of the explosion at Oppau remained unknown as all those involved in the process were killed but is relevant that compacted and encrusted AN at the bottom of silos used the anti-caking procedure of using small charges of dynamite to loosen the fertiliser. A generally accepted total of around 560 workers and members of the public died and some 2,000 were injured.

The upside of the use of AN is that it has been a useful fertiliser for agriculture and has helped increase crop yields and reduce famine and disease for over a century. As an explosive it has military and civil uses including as a cheap, low-tech blasting agent in quarrying. It has been used in a variety of fertilisers, mixed with other substances to enhance certain properties of the fertiliser. It does not burn itself but is an oxidising substance and will support combustion in combustible materials.

Decomposition of AN will release nitrogen oxides in a variety of colours including white, yellow, orange and brown. Extinction of nearby fires will not stop the decomposition immediately and toxic fumes will still be given off for some time. At 170°C it starts to melt and then decomposition occurs between 202-160°C. It is possible for decomposition to take place without a combustible material being present.

Around the town, brightly coloured orange and brown clouds of smoke could be seen and many raced to watch the Wednesday morning spectacle, a relatively common spectator sport at the busy dock. At 09:12, the fertiliser detonated sending the ship’s other cargo of tobacco, peanuts and heavy oil as well as the remainder of the fertiliser bags 1,000 m in the air. A five-metre tidal wave flooded the devastated area, the Monsanto Refinery was levelled as was much of the city and all the dock area. Forty miles away, in Houston, windows were shattered. Two Liberty ships – the SS High Flyer and the Wilson B Keene – were the only other docked ships at the time. Twenty-eight firefighters – the whole of the department, plus the chief – and many of the public spectators were killed in this first blast. Telephone operators in the city were on strike at the time which delayed mobilising the response to the incident but eventually the Texas National Guard, military and medical support flooded the city. Fire departments from the region arrived to help extinguish the fire and rescued the trapped while other police departments sent officers to maintain public order.

The SS High Flyer had around 1,000 tons of ammonium nitrate in its holds and an attempt was made to tow it away from the docks. As it was being towed it became wedged by an underwater object. Its crew abandoned ship as it drifted towards the wreck of the Grandcamp and the High Flyer started to burn. At around 01:10 on the morning of the 17th, it too, exploded, killing two people and destroying the Wilson B Keene. The sensible, precautionary evacuation of the area undoubtedly saved many lives, although the fires started by the initial explosion that were in the process of being contained by firefighters then gained momentum once again.


“Despite greater regulation and improvements in safety practice, incidents involving AN are not as rare as may be expected”


The total number of deaths of the disaster will never be known: the figure of 581 still remains the best guess but acknowledges that the condition of the bodies, the presence of foreign seamen and unrecorded numbers of labourers will make a definitive number impossible to achieve.

Despite greater regulation and improvements in safety practice, incidents involving AN are not as rare as may be expected. In 2001, 400 tonnes of ANFO (ammonium nitrate/fuel oil) exploded in Toulouse killing 30, injuring 10,000 and leading to 14,000 cases of acute post-traumatic stress. In 2013, in West, Texas, a fire at the West Fertilizer Company, 30 tonnes of granular AN fertiliser in a 7m high bin exploded killed 12 firefighters and emergency responders as well as three volunteer firefighters. Two hundred and sixty were injured and 150 buildings damaged or destroyed.

explosion in Beirut


Terrorist Usage

The use of ammonium nitrate as an explosive has been a lesson that terrorists have not been slow to learn – its ubiquitous availability, unsecured or poorly protected storage areas (how much security should a farm require?) means that it is almost readily available at an agricultural premise near you. ANFO is a commonly used bulk industrial explosive (quarries, open cast mining, avalanche protection and civil construction etc) and consists of 94 per cent granular AN (in the form of special granules called ‘prills’) and six per cent fuel oil.

Sometimes called fertiliser bombs, the Irish Republican Army (IRA) used ANFO in truck bombs in their campaigns up to the mid 1990s. In 1973, IRA ANFO car and truck bombs consumed 21 tonnes of fertiliser. The notorious Bishopsgate bomb in London in 1993 killed one and caused £350 million of damage and some consider this one event as being pivotal in initiating peace talks as the financial cost to the city of London was prohibitively high. ANFO bombs have been used in all five continents as a terrorist weapon and included the attack on the Alfred P. Murrah building in Oklahoma City in 1995 by Timothy McVeigh and Terry Nichols, the Delhi Bombings in 2011 and in Hyderabad in 2013.

While legislation and security measures continually make AN harder to get, a cat and mouse game is being continually played out in secret as bomb making materials in volume become scarce. There was, maybe still is, the belief (possibly just an urban myth) that the AN stored in Beirut was intended for use as a weapon at some future date if the political and military systems start to collapse.

The devastating explosion in the Port of Beirut will have many unfortunate consequences, both direct and indirect. The lost and broken lives are the obvious outcomes but in a damaged country, slowly recovering from the trauma of nearly half a century of conflict and civil war, the destruction could set back development a decade or more or even allow the country to spiral into a new conflict. The weakening, or absence, of a clear legislative framework, and ineffective enforcement is something that can happen to any society.

Before we in the “sophisticated” rarefied, atmosphere of Western Europe, particularly the UK, make any judgement, we should remember that our legislation and guidance is not always clear or enforced effectively and there is a 25-storey building in the west of the capital which shows graphically the high water mark of our hubris.


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