How large an explosion would the congressional bomb threat make if he had what he said

So from this article on the threat:

At one point he claimed he had a “toolbox full of ammonium nitrate.” At another, he said police should ask their experts “what a 7-pound beg of gunpowder would do with 2.5-lbs. of Tannerite.”

Well we don’t know whether the police ever asked those experts, so I’m doing it now.

What would a 7-pound beg of gunpowder do with 2.5-lbs. of Tannerite and a tool box full of ammonium nitrate?

Also add in a whole bunch of lose change as shrapnel.

He claimed he would destroy two and a half blocks, which is patently absurd, but how large a blast radius could it have had?

Is THAT what all that change was for? I was scratching my head over the pile of pennies I saw in the video, and he said something about half a roll of nickels that I didn’t catch. I was commenting to my friend, “So, that’s where all of the coins are!”

The energetic yield of ANFO (ammonium nitrate and kerosene/fuel oil) is quite variable depending on the absorption of the petrofuel and the granularity of the AN, but optimal yield is about 75% equivalent of trinitrotoluene (TNTeq). Raw (untreatred) AN is about 30% TNTeq in quantity would be unlikely to detonate in that small of a quantity without a large shock wave, although it could certainly provide an oxidizer to enhance the deflagration of gun powder. I don’t know what the TNTeq of Tannerite (‘binary explosive’ that is a fuel of powdered aluminum and an ammonium nitrate/ammonium perchlorate oxidizer with an ignition catalyst/sensitizer) but my WAG is that it somewhere in the range of Emulex at around 80% TNTeq. Confined black powder is about 55% TNTeq.

So, maybe 9-15 lbs TNTeq, assuming a generously sized toolbox and intimate contact to and confinement of gunpowder and AN/ANFO. That is certainly enough to male an impressive bang, throw some shrapnel at potentially lethal velocities to about a hundred meters or so, and break windows for a couple of blocks in every direction, but far from “destroy[ing] two and a half blocks”. It would certainly mangle but not completely destroy the vehicle it is in or leave a large crater beneath it.

What a blowhard!

Stranger

Dammit, ninja’d by @Stranger_On_A_Train .

I tried looking it up to, but my references don’t list Tannerite. “Gunpowder” seems a little too vague to me too; was it ‘black powder’, nitrocellulose, nitroguanodine, etc.? Regardless, it sounds like “Amateur Hour on Wanna-Be Nite.”

Tripler
I can only type so fast.

I’m still curious to compare to your independent estimate. I just threw some numbers together quickly and made some round guesses on yields.

I was assuming a non-double base smokeless propellant. Add in some nitrocellulose or nitroguanidine and good confinement and the yield could easily double, but this oaf doesn’t seem like the brightest bulb on the Christmas tree.

Stranger

Thanks. That was a bit bigger than I thought. My wild ass guess would have been something like shrapnel at 100 ft rather than 100 yards.

Assuming that Tannerite has a yield and detonation velocity roughly equivalent to Emulex or some other commercial blasting explosive, it could fling shrapnel quite far at near rifle speeds for something solid like a lug nut . However, the blast radius of ensured lethality would be much less; probably only 10 meters or so, and most of the shrapnel being sheet metal or tempered glass fragments that are unlikely to kill and would be stopped by essentially any barrier.

Also, you have to mix Tannerite thoroughly to get it to explode. The separated components are not especially energetic by themselves. I guess he could mix it beforehand and transport it but…I wouldn’t. You can find videos of people (idiots) shooting cars and appliances online, including one future Nobel laureate who decided to pack a lawnmower with the stuff and have the blade come back at him and take his leg off (or so he yells).

When you see people throw a hand grenade in movies and the result is a couple dozen people being blown several meters back, it’s pure movie bullshit; a typical fragmentation grenade has a “lethal distance” of about 5 meters, but unless it actually explodes in your lap or puts a chunk of shrapnel through your neck, the odds that it will actually kill you are not that high. You’ll likely just be left with a terrible ringing in your ears and an inability to remember your serial number, home address, and dog’s name. I knew a guy who claimed to have had a grenade explode “pissing distance in front of me” (I’m pretty sure it was at least ten or fifteen feet on the basis that he still had vision and at least some hearing) in a ‘friendly fire’ incident, and except for a few new holes in his utilities and a dent in his steel helmet, remained unscathed. Maybe it was just a freak ‘saving throw’ but he said he never bothered carrying grenades after that, preferring to trade the weight for a couple of extra magazines for his rifle.

Stranger

Based on where I understand him to have been parked, once pedestrians had been evacuated from the immediate area the damage he could do was minimal.

He was parked out front of the Jefferson Building of the Library of Congress, which is across the street from the Capitol grounds. But the Capitol building itself is set back hundreds of yards from the road. Likewise the Jefferson Building is set back with intervening stairs and plazas and is made out of solid marble (as well as whatever security upgrades have been made since 9/11).

The only likely victim would have been the Court of Neptune Fountain, which while regrettable is mostly notable for vandals constantly stealing the fig leaf that they added to cover Neptune’s dick.

To be fair, he might have been a really strong pisser.

He’d need a couple thousand pounds of ANFO for that kind of damage.

The RE factor of Tannerite is .55