NJ Paranoia

Saddle Brook man, allegedly stabbed by wife, is arrested on weapons-related charges - News - NorthJersey.com:

(August 08, 2014)

Just canisters of black gunpowder removed earlier were enough to pose a danger to nearby homes, according to Kugler. He said the amount appeared to more than 30 pounds, more than the amount that can be legally stored. “Our goal is to document and remove the gunpowder and render the house safe,” Kugler said. “Certainly the amount that is in there has a potential to be a hazard not only to the house but to the adjacent neighbors as well.” 

(H/Tip:  Bitter)

It's funny, but learning that your neighbor had 30 pounds of black powder stored in his home frightened his neighbors.

But if he had two Cadillacs in his garage with gasoline in their tanks, they wouldn't have thought twice about it.

Which is interesting, which you look at the "Energy Density" of gasoline compared to gun powder. *
According to my figures, if he was storing cars in his garage instead of gunpowder in his basement, his neighbors would have been MUCH more at risk in case of fire.

But people tend to freak out when they learn that gun powder has been stored next door.




*  (I couldn't find a direct comparison of Black Powder to Gasoline, so I'm citing this table of Gun Powder to Gasoline.)

Gasoline is listed at an Energy Density of approximately "46".
Gun powder is listed at an Energy Density of approximately "03".

Which suggests that gasoline is approximately 15 times as powerful as gun powder.

Let's assume that a single Cadillac has a tank capacity of 20 gallons (they ARE gas hogs, you know).  At a ratio of "a pint a pound" of liquid, and sixteen pints per gallon --- that would be on the order of (16 x 20) 320 pints in the tank of a single Cadillac.   Or, think of it as 320 pounds of Gasoline.

One pint is the equivalent of 0.43 liters 320 pints = 137 liters,

Energy Density:  about (137x 46) just under 6,330 MJ.

That's how much "Energy Density" confined in a tank with 20 gallons of gasoline.

Now let's look at Gunpowder.  (Again, we're assuming for the moment that Black Powder has the same "Energy Density" as gun powder.)


Convert 2.2 lb of gunpowder to weight;  2.2 lb/KG of gunpowder x 30 lbs of gunpowder = approximately 15 KG of gunpowder.

Energy Density of 15 KG gunpowder  (15 x 3)  = approximately 45 MJ.

So, One Cadillac with 20 gallons of gasoline is (6,330/45) 140 times as powerful as 30 pounds of gunpowder!

This guy would have had to stored over 700 pounds of gunpowder to equal the explosive power in a single tank of gas!

(Okay, certain conditions would have to prevail, such as the gas having boiled in the tank to overcome its liquid state .. which is why I posited TWO Cadillacs.)

So if black powder is 140 times as explosive as gunpowder, maybe they had cause to be upset.

But I doubt it.  It's emotion that drives fear, not rationality.

___________________

I'm willing to accept that my math contains some errors, but I'm more concerned about the Energy Density of Black Powder than that of Gunpowder.   I'm pretty sure that the difference between these two types of propellants is less about the Energy Density than the greater tendency of Black Powder to explode when met with a flame, than gunpowder (which, if not confined, merely burns).

I am comfortable with the supposition that mere gunpowder is less volatile than liquid gasoline, and also less "explosive" than Black Powder.

But then, LIQUID  gasoline merely burns, too ... unless it is is heated to the boiling point (as it would be in the fuel tank of an automobile, during a house fire); which causes what is essentially a Fuel-Air explosion.   This is the process called being "aerosolized".

If a structure fire burns an automobile in the garage, say, then in doing so the gasoline in its tanks will boil and emit vapors which are comparatively explosive ... which is why a half-tank of gasoline is more dangerous in an enclosed environment tna a full tank of gasoline.  Regardless of what you see on TV, an automobile is much less likely to "Explode" out in the open.  Burn?  Damn right.  Explode?  That requires a much more  limited set of circumstances.  In a confined environment, the temperature will more likely reach the boiling point before the shell of the fuel tank ruptures.