Was there a nuke at Port Chicago? I dunno. But I do know we were spending billions of dollars to build any kind of nuke to end World War II at that time, and if we’d had it, it would have been shipped and used. And it’s worth thinking about as a mental exercise on just how powerful even very weak nuclear explosions are.

A 2 KT blast has the explosive power of 2 kilo-TONS of TNT (the T stands for Tons = 2000 pounds) so a 2 KT blast = 2*1000*2000 or 4 MILLION pounds of TNT. Since TNT has a density of 1.65 grams per cc and there are 454 grams per pound, a pile of TNT this big would be 1.135 billion cubic centimeters and would form a cube 1040 centimeters on a side. Thus a (hypothetical?) 2KT uranium hydride bomb is equivelent to a cube of pure TNT 34 feet long, 34 feet wide and 34 feet high. There was not this much high explosive at Port Chicago, period.

You need at least 10 TNT cubes like this to equal a Mark I uranium metal bomb dropped on Hiroshima. And remember, these are atomic (fission) weapons.

In the 1950s we moved up to hydrogen (fusion) bombs which were so destructive the big ones were tested out in the Pacific Ocean. As a result very few people ever saw their true destructive power which was in the MEGAton range. For example, the W-53 that was carried in the old Titan II missile (same as the NASA launcher for the pre-Apollo Gemini program) had a 9 megaton punch or 9*1000*1000*2000 = 18 billion pounds of TNT. Do the math, the equivalent cube of TNT would be 560 feet long, 560 feet wide, and 560 feet high. Look it up, a single W-53 warhead was the equivalent to THREE blocks of TNT each the size of a World Trade Center tower – all compacted into a machine the size of a small car.

What’s really scary to me is that atomic weapons were only tested above ground for 17 years (1945 to 1962) and hydrogen fusion bombs for only ten years (1952 to 1962) and it’s been FORTY years since anybody has seen one of them go off (excluding the Chinese and French with their relatively few and small tests since 1962). Thus (A) not only are these things mind-bogglingly powerful but (B) nobody today has any first-hand experience on just how powerful they really are.

To me this is a recipe for a future political disaster. You cannot grasp the implications of what you are ordering when you authorize a nuclear strike from computer simulations and reports you got from a filing cabinet.

I actually think it would be in humanity’s best interests to declare a freeze on the above-ground test treaty once a decade and gather all world leaders together where they could observe firsthand one of these things going off. Otherwise they’re gonna forget just how many zeros they’re really dealing with here.

This argument conveniently forgets two different issues of scale. The first is that a cargo ship can contain more than a thousand tons of high explosives, and each pound of modern HE may be comparable to 4-6 pounds of TNT. Put them together and you have a yield around 5kt in conventional explosives. But where a nuclear bomb might fit into a parking space, the cargo ship may require a football field.

The second issue of scale is the damage caused by large explosions does not scale linearly with their yield. I seem to recall it was something along the lines of a 2/5 power law. At first glance, the damage caused by a 20kT nuclear explosion and a 5kT conventional one will look fairly similar. (Excluding any fires set by the nuclear “flash.”)

There are several other, well-known reasons why the Port of Chicago and Halifax explosions caused so much damage. E.g., the nuclear explosions were airbursts, and air is highly compressible. The conventional explosions were in ships, and water is highly incompressible and the effects of explosions carry far. This point was driven home during subsequent tests in the South Pacific – most if not all ships survived a nearby nuclear airburst. But a subsequent test, denonated far underwater, threw a column of water high into the air and snapped the spine of numerous ships.

Also, here are some interesting stats from chapter 9 of Vogel’s book:

The buildings of the Naval Magazine were damaged extensively; sporadic damage to structural members of buildings was proven up to 13 miles – Suval [railroad] Station, California; plate glass was broken up to 35.5 miles – Petaluma, California; and a legitimate claim for plaster damage was reported at 48 miles – Calistoga, California.

Death count: 320 dead, 81 bodies recovered, of which 30 were positively identified.

A pilot flying at 9000 feet saw pieces of white-hot metal rise above his altitude.

I’m impressed…