The Science and Philosophy Forum

An enormous explosion has destroyed the municipal port district in Beirut the capital city of Lebanon.

https://www.theguardian.com/world/2020/aug/04/cursed-shock-despair-beirut-explosion-rocks-city-lebanon

The explosion was said to have originally been triggered by a smaller fire in a pyrotechnics warehouse, but as firefighters struggled to bring the blaze under control, a much larger explosion took place in a nearby munitions storage area that was being used to hold ordnance that had been impounded after decades of civil war in the country.

First reports say that at least 2,500 people have been seriously injured, and that at least 25 people are known to have been killed.

An entire hospital located not far from the port district is said to have been demolished by the blast which was heard 145 miles away in Cyprus. People who were up in the mountains surrounding the city were said to have been knocked off their feet by the blast wave.

Emergency services have made a nationwide appeal for blood donors in all the major cities of the country

Video footage shows an enormous fireball, as well as a massive condensation dome of water vapour expanding over the city in the rarefaction zone of the blast wave.

Eye-witnesses likened the devastation seen in central Beirut to that of a nuclear bomb. Given how many hundreds of tons of military grade high explosive may have been detonated in this blast, it is not difficult to understand why.

According to a breaking news report on the BBC, the Lebanese government are saying that 2,700 tons of ammonium nitrate that had been in store for six years blew up.

ETA - If correct, this would make the Beirut blast one of the largest non-nuclear man-made explosions in history. It would be surpassed only by the 2.9 Kiloton explosion of the ammunition ship SS Mont-Blanc in Halifax harbour Nova Scotia on 6 December 1917 which claimed the lives of 2000 people and destroyed most of the town.

An informative factfile on the Sky News website has many new photographs and videos of what happened as the Beirut disaster unfolded.

https://news.sky.com/story/what-happened-in-beirut-the-explosion-that-devastated-a-city-and-shocked-the-world-12043205

A report by CNN discloses that the 2.7 Kilotons of ammonium nitrate fertiliser arrived in Beirut aboard a Russian freighter back in 2014. The shipment was originally bound for Mozambique, but became stranded in Beirut after the ship’s owners became insolvent, and unpaid crew members abandoned the vessel.

https://edition.cnn.com/2020/08/05/europe/lebanon-russian-ship-blast-intl/index.html

For some incomprehensible reason, harbour authorities allowed the dangerous cargo to be off-loaded and stored in an unsuitable quayside warehouse.

This warehouse was apparently adjacent to another warehouse that was used to store fireworks. It was also adjacent to yet another warehouse that housed most of the medical and pharmaceutical supplies for all the hospitals in Beirut.

Just to complete the catastrophe, the warehouse was immediately behind a set of tall grain silos that were acting as a strategic store for 85% of the country’s entire supply of wheat, all of which has been now been either contaminated or destroyed. The only upside is that the tall grain elevators may have acted as a blast wall that shielded the residential city centre from some of the worst of the explosion.

I endorse the restraint in not giving in to the seductions of alliteration -- "big bang batters Beirut" would have tempted me for the subject line.

Sad that this happened to a city whose past few decades must already have some residents feeling their city is cursed. I hope the US gives every support possible to the Lebanese.

The storage situation is like a caricature of incompetence that, written in a novel, would have strained reader credulity. I mean, fireworks? Really?

To put this in context: the massive explosions which devastated the port district of Tianjin in China almost exactly 5 years ago on 12 August 2015 involved the detonation of just 800 tons of ammonium nitrate.

http://www.sciencechatforum.com/viewtopic.php?f=129&t=29304&p=286780&hilit=Tianjin#p286780

The Beirut blast apparently involved three times that amount of ammonium nitrate - 2.7 Kilotons..

The Tianjin disaster began with a fire inside an overheating shipping container of nitrocellulose. The fire crews who arrived and doused the flames with water didn't realise that substantial amounts of calcium carbide were stored nearby. The hydrolitic reaction released large quantities of acetylene gas which formed an explosive fuel-air mixture that detonated the 800 tons of ammonium nitrate. (Large quantities of potassium nitrate and sodium cyanide were were also present).

The eerie white vapour dome seen in the early moments of the Beirut explosion is a testament to the power of this blast. It's a phenomenon normally only seen in films of atom bomb tests such as the Crossroads Baker test at Bikini atoll in July 1946 which was a 23 Kiloton underwater test.


https://www.youtube.com/watch?v=gm79CUjqcZ8

It's like a Wilson cloud chamber effect. The sudden drop of air pressure behind the blast wave causes all the atmospheric water vapour to condense briefly in a hemispherical dome of white cloud.

Sky News has published a video montage taken from the 230 CCTV security cameras at the Saint George hospital in Beirut which was severely damaged in the explosion.

https://news.sky.com/story/beirut-blast-cctv-captures-moment-huge-explosion-devastated-hospital-12047452

There were 17 fatal casualties amongst the 300 staff and patients at the hospital. Given the destruction shown, it seems quite incredible that there weren't many more.

The Saint George hospital which specialises in neo-natal care is already repairing its equipment and putting its facilities back into service.