That was my thought as well. Besides, any 2nd year Physics student can design a simple fission bomb that will do the job. The materials for that are a lot easier to come by. It was an interesting novel in spite of its flaws.
Depends on what you’re aiming to do.
For maximum fallout, you want a ground burst, or even slightly sub-surface, as that’ll incorporate the most dirt in the fireball, and that dirt will come down as highly radioactive dust.
For maximum blast/flash, you want an airburst, which is basically to detonate the weapon at the correct height to maximize a specific overpressure. That height is going to vary based on the weapon’s yield as well as the overpressure you’re looking to maximize. So if you wanted to blow out as many windows as you can, you’d be looking to maximize your 1 psi overpressure area, but if you’re looking to utterly destroy as much as possible, you want to maximize your 5 psi area. These are typically thousands of feet in the air- for Fat Man, the weapon used at Nagasaki, that 5 psi optimal height is 2800 feet. Of course, detonating a nuclear weapon high in the air minimizes fallout, as the only real material that constitutes fallout for airbursts is the material of the weapon itself. That’s why fallout wasn’t a major contributor to deaths at Hiroshima and Nagasaki, for example.
Finally, if you want to make a political statement and do something like obliterate a specific prominent building, you’ll probably want a surface burst for the smoking crater effect, independent of overpressure, fallout, etc…
As long as I’m free to fill up an airliner and precipitate Armageddon, might as well make it a gigaton and obliterate all the prominent buildings…
Gigatons is impossimpible. ‘Tsar Bomba’ was only 58 MT, and even that weighed in at 27 tons.
I don’t know the OP’s airliner in mind, but I’d have to see the gross max takeoff weight of his proverbial Airbus before we start getting into the gigaton-sized weapons.
Tripler
That’d be one big-assed Gadget, youbetcha.
They get more efficient as they get bigger, provided most of the yield is from fusion. Tsar wasn’t bad, at ~2 kT/kg. Ted Taylor famously stated the theoretical limit was something in the 6 kT/kg., and the Mk-41 US weapon came in at a projected (it was never fully tested in 3-stage form) 25 MT yield, while weighing 4,850 kg.
Scale up equals screw up, and getting all of the stages to ignite fully on a multiple staged device is going to be a challenge. But I don’t think it completely impossible. These guys claim a maximum revenue payload of 113,000 kg for a 747-400 freighter. 747-400F specifications. No idea how far that’ll fly, carrying that load, but that’s room for a pretty big bomb.
Wasted energy, of course. 25 MT will wreck whatever you want, terrestrially.
Hence the value of MIRVed ICBMs.
Converted to this scenario, that’s a half dozen RJs or Ryder vans spread around the target city. For X kg of fissile material at Y level of tech that gives you by far the most city-busting power.
Your surety, communications, and infiltration problems sound a lot harder though for your example. Certainly a lot more efficient destruction though, provided the bad actor has all of the primaries and ancillary apparatus to make multiple devices beyond one. Make it with diverted ex-Soviet HEU to really muddy the waters.
It thankfully hasn’t happened yet, and no doubt if it God Forbid does, like 9/11, we’ll no doubt smack our heads and say, '“Doh!”, that such a vulnerability hadn’t been properly addressed.
Agreed all the bad guys’ problems go up almost exponentially with trying to emplace more than one warhead.
As to DC itself I expect there are rad detectors on every major highway and some level of minor roads into the area. Smuggling a nuke into the city on the ground is going to be very hard to pull off. Into e.g. Palm Beach, or Cleveland, not so hard.
As we’ve discussed in other threads, the real post-explosion problem is going to be the hysteria. An awful lot of greater DC may be undamaged, but also unusable. As the fallout mess drifts typically northeast, this will have further impacts on first Baltimore then Philly and eventually greater NYC.
If you (any you) think people are excessively hiding at home from the virus that’s nothing compared to them hiding from (or fleeing from) radiation. Despite the fact radiation (or its absence) can be readily detected with gizmos ordinary citizens can buy. If you thought there was a run on TP and masks you ain’t seen nothing compared to the run on Geiger counters.
No argument there, providing we’re talking about modern-nuclear powers doing the manufacturing. Kim Jong Un can’t get to that level of efficiency, even with his current state of science.
I also have subtle issues with that chart, but that’s an in-person-and-yer-gonna-buy-me-two-rounds-of-coffee discussion.
Tripler
I drink java, and I know things.
I remember reading about how after 100 megatons you start to get rapidly diminishing returns with nuclear weapons due to most of the blast now radiating upwards instead of outwards. A gigaton nuclear weapon would still do a gigantic amount of damage but it would be incredibly inefficient to use.
The US Air Force however at some point apparently considered an entirely theoretical gigaton nuclear wearhead design which means there must have been some way to fly it.
FYI all:
in another now-closed complaint thread someone has accused us here of teaching the terrorists how to attack Washington. With details and everything!1!1!!
Nothing here that 30 seconds with Google won’t find elsewhere in more reputable sources, but we’re aiding and abetting.
Color me suitably chastened. Not.
- Buy a 737
- Buy a bunch of plutonium. (Don’t ship it all in the same box!)
Yeah, pretty much specific directions there. I’ll just order it all from Amazon then build it.
My now-archived post went a little “rabbit holey,” insofar as commenting on how ineffective buying an airliner and Plutonium would be. Why innefective? Amazon quit listing 737s back in 2004.
Tripler
Dude, just lob some cruise missiles.
Are there underwear pants gnomes? I was told there would be underwear pants gnomes. And profit!
Tripler, I would have been interested in the contents of said rabbit hole, but I suspect it’ll have to wait until that coffee klatch you mentioned. So long as they have freshly roasted, unwashed Sumatran or Ethiopian…
Hilarious that this site is thought to impugn national security in any way, shape, or form.
I don’t know about by air, but roads into the US have detectors, not just for radioactive material itself, but for shielding for radioactive material. And the Coast Guard has similar systems that they can use for checking incoming ships. See, the trick is that you look for the natually-occuring cosmic rays: Any shielding that can hide a nuke is also going to cast a cosmic-ray shadow.
And if you’re attacking Washington, you’re not going to particularly want fallout. The valuable targets in the DC area are all hardened enough that you’re going to need a direct-hit blast to take them out, and maybe not even then. Attacking New York with fallout, though, that might make sense.
The jist of it was questioning the OP’s method of putting all his eggs into one [airliner] basket, with one large-yield weapon, where anything can go wrong with delivery. Better to use smaller yield weapons (save on plutonium) and saturate your target’s defenses with multiple “inbounds.” I felt it was a little too ‘off topic’ with some of the disussion, so I removed it to keep the good nuke vibes going.
I used to work with some of those detection systems. Nifty stuff, if I do say so myself.
Tripler
Drinkin’ coffee today? Come and join me for a mornin’ cup of “Up and Atom!”, the new breakfast blend from TripCo Industries.
The best feature of Up and Atom!? It’s self-heating! 
I’m stealing this. 