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-   -   Things that make you go "Hmmmm…" (https://www.mersenneforum.org/showthread.php?t=1256)

axn 2020-08-05 09:42

[QUOTE=Batalov;552603][url]https://en.wikipedia.org/wiki/Hybrid_Air_Vehicles_HAV_304/Airlander_10#/media/File:Airlander_-_Mission_Module_Fitting.jpg[/url][/QUOTE]

Real air vehicles have curves.

xilman 2020-08-05 09:57

[QUOTE=Batalov;552603][url]https://en.wikipedia.org/wiki/Hybrid_Air_Vehicles_HAV_304/Airlander_10#/media/File:Airlander_-_Mission_Module_Fitting.jpg[/url][/QUOTE]Widely known as the flying bum.

Sorry, we need to watch our language around here.

Ought to be widely known as the London Derriere.

nomead 2020-08-05 10:57

[QUOTE=xilman;552606]Ought to be widely known as the London Derriere.[/QUOTE]

Filled with something lighter than Londonderry air?:jokedrum:

chalsall 2020-08-05 15:16

[QUOTE=Dr Sardonicus;552577]So plain old ammonium nitrate can make a big explosion if you simply get enough of it hot enough.[/QUOTE]

I didn't know about this until I was watching the BBC during dinner last night.

WOW!!! That was energetic!

Clearly, the wavefront is super-sonic for a good second or so (the radius covering over a km) (all guestimates).

I'm no expert on explosives (although I've been nearer than I should have been for many), but my understanding is Ammonium Nitrate (AN) needs to be mixed with a binder/accelerant to produce that kind of event.

In the mining industry, it's used (mixed with diesel) to pour into drilled holes in a wall-front, and trigged with blasting-caps.

Which brings up a point... My understanding (quite possibly incorrect) is AN itself needs to be contained to create a high energy event, or else triggered with a super-sonic primer (otherwise it just burns really-really well). Were the fireworks themselves powerful enough for this?

kriesel 2020-08-05 17:12

[QUOTE=chalsall;552640]I'm no expert on explosives (although I've been nearer than I should have been for many), but my understanding is Ammonium Nitrate (AN) needs to be mixed with a binder/accelerant to produce that kind of event.
... My understanding (quite possibly incorrect) is AN itself needs to be contained to create a high energy event, or else triggered with a super-sonic primer (otherwise it just burns really-really well). Were the fireworks themselves powerful enough for this?[/QUOTE]Your understanding has been refuted by references and experience.
[URL]https://en.wikipedia.org/wiki/Ammonium_nitrate#Disasters[/URL]
The AN storage was initially unclear. Recent reports say a warehouse, so a confined space. Cargo ships containing it have exploded after a fire.
"It is unacceptable that a shipment of ammonium nitrate estimated at 2,750 tons has been present for six years in a warehouse without taking preventive measures that endanger the safety of citizens"

Counts and estimates are now 135 dead, over 5000 injured, dozens missing, 300,000 homeless, and 85% of the nation's grain lost, previously stored in a collection of silos at the port. [url]https://www.usatoday.com/story/news/world/2020/08/05/beirut-explosion-what-we-know-massive-blast-killed-100/3297195001/[/url]

xilman 2020-08-05 17:26

[QUOTE=chalsall;552640]Which brings up a point... My understanding (quite possibly incorrect) is AN itself needs to be contained to create a high energy event, or else triggered with a super-sonic primer (otherwise it just burns really-really well).[/QUOTE]NH[SUB]4[/SUB]NO[SUB]3[/SUB] itself doesn't burn[SUP]*[/SUP]. It undergoes exothermic decomposition to (primarily) N[SUB]2[/SUB] and H[SUB]2[/SUB]O on heating. The reaction is somewhat energetic and the products are gaseous under typical conditions. Insufficiently contained gases expand rapidly.

Astute counters of atoms will note that the formulae above do not contain equal numbers of oxygen atoms. The excess can either react with hydrocarbons to produce CO[SUB]2[/SUB] and more H[SUB]2[/SUB]O, as used to good effect in ANFO, or failing anything else, nitrogen to produce NO[SUB]2[/SUB]. The latter is a deep orange-brown colour. purely by chance I saw some of the very first videos to hit the net, long before any official statement was made as to the probable cause of the explosion. I knew within seconds that the gas cloud was almost certainly caused by a large amount of ammonium nitrate undergoing explosive decomposition.

* Not in a nitrogen / oxygen mixture anyway

chalsall 2020-08-05 17:47

[QUOTE=xilman;552661]Insufficiently contained gases expand rapidly.[/QUOTE]

Sorta by definition.

Much like gun-power just "decomposes quickly" if not contained (and briefly constrained) within a shell casing.

nomead 2020-08-05 18:43

[QUOTE=kriesel;552659]Counts and estimates are now 135 dead, over 5000 injured, dozens missing, 300,000 homeless, and 85% of the nation's grain lost, previously stored in a collection of silos at the port. [url]https://www.usatoday.com/story/news/world/2020/08/05/beirut-explosion-what-we-know-massive-blast-killed-100/3297195001/[/url][/QUOTE]

Maybe not quite 85%.
[URL="https://iranpress.com/middle_east-i150402-lebanese_official_wheat_in_beirut_grain_silos_can_no_longer_edible"]https://iranpress.com/middle_east-i150402-lebanese_official_wheat_in_beirut_grain_silos_can_no_longer_edible[/URL]

"However, it is believed the silos did not contain huge quantities of grain at the time of the explosion, as the country tried to meet a shortage of bread that surfaced recently due to the current financial crisis"

But it sure makes more difficult to import more supples. While it was not the only port in Lebanon, it was the largest, handling the majority of food and fuel imports, and all that infrastructure is now gone.

Batalov 2020-08-05 18:51

Re: [QUOTE=xilman;552661]Insufficiently contained gases expand rapidly.[/QUOTE]
I think many forum members would (in quite a bit of contrast with general public which gave it only 31% on Rotten tomatoes) appreciate the recent film called 'The Night Clerk' (2020).
There, at a certain point, the protagonist's mother tells the detective: "[I]That [/I]was a joke."

This is how our kind of people joke!
Of all people, I appreciate this sentence much more than others, in part because my college diploma says: "Specialization: kinetics of fast-running chemical processes." [SPOILER](read: "explosions specialist") ... кинетика быстропротекающих процессов[/SPOILER]

kruoli 2020-08-05 19:51

A long time ago, we had a similar explosion in Germany: [URL="http://en.wikipedia.org/wiki/Oppau_explosion"]http://en.wikipedia.org/wiki/Oppau_explosion[/URL]

firejuggler 2020-08-05 20:02

In France, too [URL]https://en.wikipedia.org/wiki/Toulouse_chemical_factory_explosion[/URL]
The 21 september 2001
oh and.. it appear to happen... often?
[url]https://en.wikipedia.org/wiki/Ammonium_nitrate_disasters[/url]


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