Oxy-acetylene gas bottle crash explosion - video

Explosion videos on the net are like dessert. Too many, and you become intellectually fat and lazy. But an occasional high quality one is worthwhile. That means: good footage, historical/engineering/scientific interest, and no gore.

Here we have a Russian crash of a truck carrying an estimated 36 bottles of what is believed to be oxy-acetylene. The bottles catch fire, explode, and turn into projectiles. No reported injuries.

3:50 video of the crash and explosion:

https://www.youtube.com/watch?v=FG1LGKieTxY

Why no pressure release valves? Are the valves rendered useless by the heat of the explosion? Is this another example of a BLEVE - a Boiling Liquid Expanding Vapor Explosion?


Previously:

https://www.homemadetools.net/forum/...392#post116759
https://www.homemadetools.net/forum/...215#post101010
https://www.homemadetools.net/forum/...6845#post84468
https://www.homemadetools.net/forum/...3329#post98769
https://www.homemadetools.net/forum/...062#post115400
https://www.homemadetools.net/forum/...339#post116489
https://www.homemadetools.net/forum/...5851#post82647

Several circumstances will lead up to a catastrophic and potentially deadly situation. The initial fire was most likely from the fuel tank of the vehicle. Compressed gas cylinders even when inert gases are involved become potential projectiles when subjected to enough heat. the pressure relief valves on oxygen cylinders would vent allowing the oxygen to intensify the fire, relief valves in any combustible cylinder would add fuel eventually the brass closure valves are going to soften and fail due to the intense heat. The explosions we heard would have been the tanks themselves rupturing when the flames went to bright almost white hot color those would have been oxygen cylinders the Intense yellow flames could have been a fuel cylinder. the cylinders we saw that were simply spewing a white almost clear exhaust as they were propelled could have been any of the inert gases and possibly oxygen but from the angle of the video I didn't see intense flames trying to follow them which would mean to me most of the ones escaping were not likely oxygen or fuel cylinders Some were as the video showed.
At an Army property disposal depot we were once tasked with disposing 1000s of pressurized cylinders they way this was to be done was to have the cylinders racked in safety cages then open the valves slightly and allow them to slowly vent their contents. A couple of GI's thought it might be a lot of fun to watch some of these cylinders become rockets. they stacked one on an incline then sledge hammered the valve off. A CO2 cylinder pressurized to 800 PSI was not all that spectacular. So they next used an oxygen cylinder 2500 PSI it took off like an unguided missile ricocheting off of everything in its path.My Col. and I showed up just as they knocked the valve off of a small 10,000 PSI nitrogen cylinder. The valve ricocheted off a couple items then hit the GI's with the sledge hammer in his thigh nearly severing it. The unguided 30 lb missile hit the blade of a dozer then ricocheted then struck the Col's jeep I was driving Neither of us had more time than to yell incoming. Fortunately it struck low in the front end taking out the oil pan and the crankshaft. Once he and I realized that we had survived, 3 GI's were hauled off to the Provost marshal the other was taken to the hospital All received very bad punishments.
There is a good reason why here in the USA welding supply trucks all have the cylinders tightly secured in strong racks for transport and only inert gases can be racked next to flammable gases Oxygen cylinders are always racked as far away as possible from flammables even the empties.
When I go to have my cylinders exchanged I can only carry up to 1000 lbs worth of full cylinders without hazmat placards and the hazmat endorsement on my license

Bet the driver of the small compact left brake fluid all over the road leaving the scene. Police didn't stay long.

Unfortunately there is almost nothing that can be done ot even attempt to contain any secondary fires that may start as the result of these exploding flaming cylinders until the main fire begins to burn itself out. You cannot even water bomb one of these fires as the sudden quenching of any remaining pressurized cylinders will cause them to explode into small fragmented shrapnel with up to a 1000 times the force of a regular hand grenade. That would be for all heated cylinders not just ones which were flammable. Foam or dry chemical will do nothing since the fire has its own source of oxygen. If you cold somehow blast enough CO2 to freeze the fire the same thing would happen as with water.
The best thing to do is to keep everyone 500 feet or more away from the fire until all threat of exploding cylinders has passed then move in and put it out.
That patrol officer was dumb and lucky dumb for driving past the already stopped vehicles to assess the situation. Surely he was able to see the cylinders exploding and becoming un-guided missiles long before he drove that close.
Lucky in that one of them didn't impale his vehicle before he cold back away.

This video (and others like it) are typically viral, and you can see them across the web in various social media.

But the comments and explanations that our guys post as responses are generally much higher quality than what I see out there.

Ah, that one that heads right and goes out the top right of frame by 2:51.