[smiley1437]

Over time, the explosive chemicals in the both the detonator and the main charge can frequently get MORE sensitive to disturbance, which is kind of perverse.

That's why if you ever come across any old UXO (UneXploded Ordnance) you should call the bomb squad and never touch it

[ckozlowski]

There was a great discussion I read here a year ago from a chemist who went into the details on why this occurs. I'll link the comment. Really great read.

https://news.ycombinator.com/item?id=34755399

[smiley1437]

thanks for the link! A great read as promised

[retrac]

Even if it's inert many explosives decompose into toxic compounds. Other explosives use mercury compounds for detonators, which at the worst can make the soil itself toxic to the touch. There are also gas shells, some of which had arsenic. Areas affected in that way will be poisonous for a very long time.

[bell-cot]

This. Though I would not call explosives "chemically stable", nor their degrading with time "perverse".

They are capable of energetically exploding because they are not chemically stable.

And "shelf-stable and safe for many decades" is never a priority feature for high-volume wartime production of explosives.

[genocidicbunny]

> And "shelf-stable and safe for many decades" is never a priority feature for high-volume wartime production of explosives.

Maybe not on the order of decades, but 'shelf-stable and safe for handling' is a definite concern in any ordnance production. Last thing you want is your whole ammo stockpile blowing up because a tired soldier set an artillery shell down a little too hard.

Many of the explosives used are actually fairly stable chemically and require either severe degradation to become unstable, or an external force applied to them that is sufficient to trigger their explosive effects. C4, as long as it hasn't been sitting around too long, is pretty safe to light on fire. And yet it's one of the more energetic commonly used explosives out there.

[zmgsabst]

Also, an artillery round in particular can’t go off from the shock of being thrown by an explosive right next to it.

Or you kill yourself, when your round detonates in the gun.

[slyall]

> And "shelf-stable and safe for many decades" is never a priority feature for high-volume wartime production of explosives.

The problem is that those minitions do get used many years later. Often because after a war ends there is a huge surplus of munitions you want to save till the next war.

Russia is using decade-old shells in Ukraine for instance.

The USS Forrestal fire was partially caused by 14 year old bombs that had been improperly stored. https://en.wikipedia.org/wiki/1967_USS_Forrestal_fire

[tetha]

Mh, chemical stability is usually meant in a more delicate way.

There are explosives that need other explosives to set them off. If someone gave you a pound of C4 and then evacuated your neighbors, you would probably need to do some research to set it off. With the amount of explosives moved around in the world wars, easy storage and fairly safe logistics even by minimally trained soldiers are very much a priority.

On the flipside, there are explosives which won't let you finish a sneeze in the same room. Or which decompose into the latter. You wouldn't want to move thousands of tons of these around.

[shmeeed]

Re: your last paragraph called to my mind the great french thriller "The Wages of Fear" from 1953, in which two trucks loaded with nitroglycerin need to cross rough terrain, and the viewer finds himself holding his breath quite a lot...

[genocidicbunny]

Also remade as a pretty good movie in 1977 -- Sorcerer. Had a great soundtrack by Tangerine Dream as well.