Nuclear Friday: Little Genie

What a beautiful picture of a desert sunset. Most of the readers of The Big Board probably suspect that’s not really the sun, and it isn’t. It’s nuclear weapon caught just after the secondary flash. At this brief moment it’s hotter than the sun by far, though not nearly as powerful. In 1957 this was the least powerful nuclear device ever built. AIR-2 Genie was an inelegant, but oh so practical solution to a very pressing strategic problem.

Air defense against bombers was very different in this new nuclear age. Back in WWII causing 2% losses to the attacker was considered pretty good. 5-6% was considered unsustainable. The Luftwaffe gave up its two major efforts over Britain as loss rates crept up over five percent for a few weeks each time. This is because conventional unguided bombs don’t do very much damage in proportion to the cost of the effort to drop them. It takes large numbers of very expensive aircraft. Pilots and other aircrew don’t come cheap either, they take a long time to train and not that many people are even capable of the job. So when loss rates per attack pass 2%, the balance of attrition begins to favor the defender. Hit the 5% loss point and you likely can’t build enough aircraft and train aircrews fast enough to sustain the effort. Even if you could, it’s costing you more than the damage you are doing to the enemy.

Nuclear weapons alter this balance strongly in favor of the attacker. When each bomber can rip the heart out of a city or flatten a military base, there only needs to be ONE attack, and high losses are worth it. The defender is in dire straits. The magic of attrition no longer applies. Each bomber that gets through can kill hundreds of thousands of people, cripple the economic assets of a region, and cut the sinews of war. Five percent isn’t enough any more.

So what to do? Shooting down bombers with machine guns and cannons mounted on interceptors was fine in WWII, but just takes too many planes and too much time when you need to shoot down more than half the attackers. Surface to air missiles are great in theory, but rocket engine technology of the mid-50’s was unreliable. Guided air to air missiles were  a bit beyond the technology of that time too. In 1955 an advisory commission recommended  building an unguided rocket that could be launched from a small interceptor aircraft using the then-experimental W-25 nuclear device rated at 1.5-2 kilotons. Bombers have a lot of large surfaces that would act as levers to magnify the pressure effects of a nuclear blast. The expected blast kill radius was 300 meters at highest operational altitudes. This blast effect would be much larger at lower altitudes, around two kilometers wide. At higher altitudes there would also be the possibility of a thermal or radiation kill of targeted aircraft even though the blast radius was smaller.

The W-25 warhead was a success. It was the smallest nuclear bomb ever built. The yield was only 1.5-2 kilotons, but it was tiny. You could sit in the back seat of a mid-sized car and hold a w-25 in your lap and still see over it. This would be uncomfortable because the weapon did weigh 100kg, but keep in mind, this is very small for such a huge explosion. The entire Genie rocket weighed only 370kg and was three meters long.

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There’s just one problem, you might have to fire and detonate Genie over where people live. Will the public accept that? Yes, yes they will if you show them my favorite test video of all time.

I absolutely love this video. I love how the announcer is overcome with awe and goes almost all “o the humanity” over this. This is one of the rare test videos what has the original audio and video synchronization as well. Quite a few seconds between the flash and the blast. I hope that some reader will post their estimate of the altitude of the blast. I was planning to do that in this post, but I realized the air density gradient made the math too hard and I have already done some math for this post.

So I know what you’re thinking, were these five people completely insane? No, they were not. And I am not one of those people who minimizes the risks of exposure. I have explained my views about the risks of the Operation Teapot shots in This Post. Also the test in this video was the “John” shot from Operation Plumbbob. The John test was the lowest risk shot from the Plumbbob series, which is well known as the most dangerous test series in US history. Plumbbob was appalling. Pay attention to Nevada in the video I posted here and watch 27 flashes in 1957.

Why do I say the risk was so low to the five people in the video? They had adequate shielding. Consider this. At sea level, air pressure is 14.7 pounds per square inch. That means each square inch of the largest horizontal cross section of your body has nearly fourteen pounds of stuff pressing on it. That’s a huge amount of weight. You can’t feel it because air is a fluid, so it also presses on your sides, and fills your lungs to press outward from the inside. Your heart actually pumps your internal pressure a little higher than external pressure, so you feel it even less.

I will continue using Imperial units here. I love the metric system and think the US should have switched long ago back when Nixon and Carter wanted to. I was raised to be comfortable with metric and mostly am. But while I think the Newton is an excellent unit of force, spreading it out over a square meter to make a Pascal makes a Pascal too small and uncomfortable. That’s why I will be using pounds per square inch (psi). So consider this, a cube of lead weighs .41 pounds. Standard atmospheric pressure is 14.7psi. That value divided by .41 roughly equals 36. So each square inch of atmosphere from sea level to low earth orbit is equal in weight to a stack of 36 lead cubes one inch wide. Just being under our air is the same as standing under three feet of lead shielding.

The John shot in the video was at between 18,500-20,000 feet the air pressure up there is 2/3-1/2 as high as it it is on the ground below, and that 2/3rds estimate is a little high because I don’t know the elevation of that area of Nevada, but even that estimate puts the folks in the video under the equivalent of a foot (30cm) of lead shielding. There was no risk.

And the real proof can be found in this article. These people lived long healthy lives some of them even dying in their eighties, though  I have found out that the article misidentified Frank Ball, who died at 57 from lung cancer. I think he was the officer smoking in this video, but I’m not sure. But seriously, while I believe the US was frequently careless with its nuclear tests, they were not really that dangerous compared to other public health problems. Tobacco use has killed orders of magnitude more people and continues to kill. Better standards for infant car seats have saved more years of life lost since the 80’s than all the years of life lost from nuclear tests. What’s happening in Flint, Michigan is about as bad as fallout illness from Operation Plumbbob. Leaded gasoline was worse than all nuclear testing and all death and illness from extraction and refining of nuclear materials combined. It’s important to keep things in perspective.

But back to sweet little AIR-2 Genie. In the event of a Soviet attack, most Genies would not have been detonated over heavily populated areas. The Canadian Air Force would have shot a good number of them over the arctic, and the USAF would have shot the rest over the Canadian prairie, north Atlantic, and north Pacific. The Genie was the primary air defense weapon of Canada until 1984, and began retirement in the US in 1985. As front line Vietnam-era aircraft with effective guided missiles were assigned to Air National Guard units in the late seventies, Genie became less necessary. I like to think I might have seen a Genie. My dad took me to many air shows at Ellington in the seventies and I remember seeing the Century Series jets from the late 50’s and early 60’s, but I was too young to know about Genie, so I don’t know if I saw it. They might not have had any. The Gulf Coast of the US is about the worst place to attack by airplane from the Soviet Union if you use the great circle mapper.

PREVIEW: Next week I will continue the “small is beautiful” theme to get to the lower theoretical limits of nuclear weapons, all the way down to the smallest nuclear weapon ever built. Provisional titles are “Atomic Wang” and “Nuclear Knob”. Seriously, this is a nuke system that can’t help but be phallic.

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