Nov 042016
 

Someone goes way too fast and loses control of their car: not new. The car crashes and bursts into flames: not new. The responding firefighters have to dodge explosively propelled flaming battery packs: that’s gotta be a little new.

Here’s the thing: a car full of gasoline bursts into flames has got to be a nightmare scenario for rescuers, but it is at least something that they and their technology are used to. Foam will float on top of gasoline, serve as an oxygen barrier, put out the fire. But a lithium battery fire? You spray anything water based on it, the lithium will yank the oxygen out of the water molecules and combust with *that,* leaving superheated hydrogen to roam free and burn with yet more free oxygen in the air. So don’t spray water on a battery fire. And I *believe* that an adequate lithium fire will yank the oxygen out of carbon dioxide, so don’t bother with *that.* The preferred solution for a metals fire is:

  1. Bury it in sand
  2. Bury it in salt
  3. Stand back and check your emails until the fire burns out.

CSB: Years ago I worked on a small badly run project to develop an ejector ramjet. The dimwit who ordered the components didn’t pay a whole lot of attention to safety issues or even just basic chemical or mechanical issues, and bought us a large titanium tube to serve as the combustion chamber for the ramjet. And titanium is fine, so long as you use the right alloy (6 AL 4V is a good one). But this tube was, IIRC, essentially *pure* titanium. And pure titanium burns like frakin’ magnesium. So the safety guy pitched a fit until management bought a special metals-fire extinguisher that shot out a spray of fine salt. The salt would cover the burning metal, melt, block oxygen, solidify. So as far as management was concerned, in the off chance there was a titanium fire, one of us minions could run out to the test stand and put the fire out. The agreed-upon procedure among us minions was, of course, “screw that noise,”  to sit on our asses and wait for the titanium to burn itself out. There are a lot of things worth risking your life over, and a small shed with some cobbled together rocket equipment just ain’t one of ’em. And I kinda doubt that a Tesla that has been converted into a flaming pile of rubble is one, either. Both occupants of the car died, and I suspect  that one of them was converted to a fine white ash.

Witnesses say the car was going *really* fast. One wonders if it was because the driver was a lead-footed moron, or because the car malfunctioned. Given the severity of the fire, I have doubts that that can be clearly determined.

 Posted by at 4:43 pm