# Designing a Small, Lightweight Thermonuclear Suitcase **URL:** \ **Category:** Factual Questions\ **Created:** [June 8, 2023, 5:11pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213 "2023-06-08T17:11:11Z")\ **Posts on this page:** 15\ **Page:** 3
**Author:** ![Caribbean\_cruiser](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/caribbean_cruiser/32/9349_2.png) [@Caribbean\_cruiser](https://boards.straightdope.com/u/Caribbean_cruiser)\ **Post date:** [June 9, 2023, 9:37pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/41 "2023-06-09T21:37:58Z")
Thanks for your technical know-how, folks. In my OP, I never imagined so many detailed responses–or scenarios. Just to clarify: When I mentioned “H-Bomb Samsonite luggage,” I was playing off the idea of a “nuclear suitcase” and not suggesting anything to do with an actual airport. I think my “spinner wheels” quip sent things in that direction. 😉 ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [June 10, 2023, 12:46am UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/42 "2023-06-10T00:46:19Z")
Link with pictures of Special Forces parachuting with the “suitcase nuke” ; Special Atomic Demolition Munition, or SADM. More info on development, potential employment and other nuclear demolition munitions. > **[Special Forces Parachuted With Nukes Strapped To Them During The Cold War](https://www.thedrive.com/the-war-zone/special-forces-parachuted-with-nukes-strapped-to-them-during-the-cold-war)** > > Special Forces "Green Light" teams trained to deploy small nuclear bombs called Special Atomic Demolition Munitions during the Cold War. ---
**Author:** ![ParallelLines](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/parallellines/32/3575_2.png) [@ParallelLines](https://boards.straightdope.com/u/ParallelLines)\ **Post date:** [June 10, 2023, 3:51am UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/43 "2023-06-10T03:51:03Z")
The SADM was mentioned in the OP, and repeatedly throughout the thread. 🙂 ---
**Author:** ![smithsb](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smithsb/32/12107_2.png) [@smithsb](https://boards.straightdope.com/u/smithsb)\ **Post date:** [June 10, 2023, 3:57am UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/44 "2023-06-10T03:57:59Z")
And? I am aware of that. I worked with practice weapons early in my career. The acronym and expansion were included in the blurb from the article. I added the article as more information related to development and employment. Also pictures. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 10, 2023, 3:33pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/45 "2023-06-10T15:33:45Z")
The lead picture of @smithsb’s interesting cite does give us a very graphic example of how big the thing wasn’t. And that was taken with the device inside its protective carrying case. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [June 10, 2023, 3:48pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/46 "2023-06-10T15:48:55Z")
A pure fission weapon can be pretty small. I don’t know if there’s some engineering breakthrough that would allow you to miniaturize further than that, but we have been to the point for some time that one strong person can carry such a device. I don’t know if there’s room for comparable engineering improvements for a Teller-Ulam fusion device. If there were, it would be so classified that it couldn’t come out in public anyway. ---
**Author:** ![Common\_Tater](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/common_tater/32/13846_2.png) [@Common\_Tater](https://boards.straightdope.com/u/Common_Tater)\ **Post date:** [June 10, 2023, 9:10pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/47 "2023-06-10T21:10:32Z")
The history is fascinating. Fissionable material in sufficient quantity was exorbitantly costly, and in extremely short supply after years of laborious separation from uranium, so much so that Leslie Groves, overall director of the Manhattan Project, ordered a huge (and expensive) steel containment vessel be constructed to capture the material should the first test at Alamagordo be a “dud”. It was never used. The second device, a “gun type” bomb, was considered so reliable a design that the engineers didn’t even consider testing a requirement. They knew it would work. I think that’s remarkable. So there are technical or physical considerations on how small a nuclear chain reaction can be? No bombs the size of a shoebox? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 10, 2023, 9:18pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/48 "2023-06-10T21:18:41Z")
You’d do well to read the thread first and also the various wikis and other cites on on atomic and thermonuclear weapons. Which are two very different things. For an atomic fission device, there are lower limits to the amount of nuclear material required. Smaller than that just won’t go boom. Somewhat bigger than that will be required to solve problems of inefficiency, impurity, etc., of the necessarily less-than-ideal actual physical machine and materials. As discussed upthread, very small atomic fission weapons can be built. The size of backpacks, but not the size of grapefruits. This whole thread is a discussion of the smallest thermonuclear = fusion weapon. Which also has an absolute lower limit based on nuclear critical mass, but is overall a much more complicated machine with larger limits all around, lotta magic parts, etc. ---
**Author:** ![Common\_Tater](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/common_tater/32/13846_2.png) [@Common\_Tater](https://boards.straightdope.com/u/Common_Tater)\ **Post date:** [June 10, 2023, 9:22pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/49 "2023-06-10T21:22:28Z")
Admittedly, I didn’t read everything. I denounce myself. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [June 10, 2023, 9:23pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/50 "2023-06-10T21:23:09Z")
Sorry, I probably came off shorter than I meant. ---
**Author:** ![Common\_Tater](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/common_tater/32/13846_2.png) [@Common\_Tater](https://boards.straightdope.com/u/Common_Tater)\ **Post date:** [June 10, 2023, 10:49pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/51 "2023-06-10T22:49:56Z")
LOL, no no no . . . I really should have read in more detail. I knew there was a lower limit on size for nuclear weapons. ---
**Author:** ![ParallelLines](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/parallellines/32/3575_2.png) [@ParallelLines](https://boards.straightdope.com/u/ParallelLines)\ **Post date:** [June 10, 2023, 11:38pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/52 "2023-06-10T23:38:58Z")
> [@LSLGuy](#): > > Sorry, I probably came off shorter than I meant. You mean you _went nuclear_ on @Common_Tater? 🤣 I’ll just see myself out. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 11, 2023, 4:08am UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/53 "2023-06-11T04:08:32Z")
> [@LSLGuy](#): > > This whole thread is a discussion of the smallest thermonuclear = fusion weapon. Which also has an absolute lower limit based on nuclear critical mass, but is overall a much more complicated machine with larger limits all around, lotta magic parts, etc. Not least because, I think, a fusion weapon actually requires a fission weapon to make it work. Basically, wrap an atomic bomb (fission) around the stuff you want to fuse so it becomes a fusion weapon. Just seems by its very nature it has to be bigger (not to mention more complex). ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [June 11, 2023, 9:06am UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/54 "2023-06-11T09:06:48Z")
More complex, but not bigger for a given yield. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [June 11, 2023, 5:08pm UTC](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213/55 "2023-06-11T17:08:51Z")
> [@Riemann](#): > > not bigger for a given yield. That’s fair, assuming “given yield” is “fusion-level yield”. The largest non-fusion US nuclear test was Ivy King, at 500 kilotons. > **[Ivy King](https://en.wikipedia.org/wiki/Ivy_King)** > > Ivy King was the largest pure-fission nuclear bomb ever tested by the United States. The bomb was tested during the Truman administration as part of Operation Ivy. This series of tests involved the development of very powerful nuclear weapons in response to the nuclear weapons program of the Soviet Union. > The production of Ivy King was hurried to be ready in case its sister project, Ivy Mike, failed in its attempt to achieve a thermonuclear reaction. The Ivy King test actually took place two wee... It was a stupendously large device, even though it was designed and deployed as an actual aerial bomb. It weighed in at 6,800 pounds and was 5 feet in diameter and more than 10 feet long. (Per [List of All U.S. Nuclear Weapons](https://nuclearweaponarchive.org/Usa/Weapons/Allbombs.html)) The thermonuclear [W88](https://nuclearweaponarchive.org/Usa/Weapons/W88.html) warhead used in the Trident II Submarine-Launched Ballistic Missile has a yield close to this: 475 kT. It weighs less than 800 pounds and less than 2 feet in diameter (at its broadest – it’s a cone, so its minimum diameter is zero). And less than 6 feet long. And the actual fusion device inside that conical reentry vehicle is somewhat smaller than that. But barring some breakthrough in fusion weapon technology, you’ll probably never get a small thermonuclear device with sub-kiloton yields, simply because currently you need a fission device to trigger the fusion, so that sets the minimum yield baseline. [Previous page](https://boards.straightdope.com/t/designing-a-small-lightweight-thermonuclear-suitcase/985213.md?page=2)