Oxy-acetylene gas bottle crash explosion - video

[Frank S]

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