
The Mystery of Fogbank (2009) - areoform
https://www.weeklystandard.com/jonathan-v-last/the-fog-of-war
======
PaulHoule
One thing the article doesn't say was that early attempts to recreate Fogbank
failed because the materials used to make it were too pure. They had to put
back in the impurities to get the same product.

(I read about this in a Navy magazine when my son and I slept on this ship

[https://en.wikipedia.org/wiki/USS_Little_Rock_(CL-92)](https://en.wikipedia.org/wiki/USS_Little_Rock_\(CL-92\))

as a Cub Scout activity.)

My guess about Fogbank is that it might not do much at all from a weapons
physics standpoint, but it is highly rigid so that the weapon maintains its
dimensions throughout the process of launch and atmospheric reentry, never
mind the long time of sitting in the launch tube.

Aerogels are fun materials to play with since they are amazingly light and
rigid; drop a piece on the floor and you hear a very high pitching ring thanks
to that.

~~~
areoform
At the risk of ending up at a black site. A literature review suggests that
when it is used as an interstage material - FOGBANK acts as a lens i.e. it
directs and focuses the neutron flux from the primary device and does
something with the X-Rays produced to help trigger the secondary.

Whatever it does, it is an extremely critical component worth spending god
knows how much money on.

~~~
mannykannot
IIRC, according to Richard Rhodes in 'Dark Sun', the key insight (with Teller
and Ulam disputing who had it first) needed to make a true fusion bomb (as
opposed to a boosted fission bomb) is that the fusion part has to be far
enough separated, from the fission bomb that starts it, that it can do its
thing before it is blasted apart by the shock wave from the fission bomb. That
raises the problem of how to transfer energy from the fission bomb to the
fusion part, and the solution is to surround the latter with something that
will absorb some of the X-rays and vaporize, thus applying a very uniform
compression of the fusion part. Wikipedia says that polystyrene foam was used
in early bombs [1], and apparently polyethylene was used in the original Ivy
Mike device. I have no idea whether this is actually the purpose of fogbank.

One problem with re-creating or replacing any special material critical to the
weapons' functioning is that test-ban treaties forbid an end-to-end test of
bombs using the new stuff.

Update: see also 'Speculation on Fogbank' [2]

[1]
[https://en.wikipedia.org/wiki/Thermonuclear_weapon](https://en.wikipedia.org/wiki/Thermonuclear_weapon)

[2]
[https://www.armscontrolwonk.com/archive/201814/fogbank/](https://www.armscontrolwonk.com/archive/201814/fogbank/)

~~~
EdwardDiego
Thank you to yourself and the person you're replying to for an interesting
thread (with links!).

------
adolph
Wikipedia on Fogbank:

 _in the words of former Oak Ridge general manager Dennis Ruddy, "The material
is classified. Its composition is classified. Its use in the weapon is
classified, and the process itself is classified."_

[https://en.wikipedia.org/wiki/FOGBANK](https://en.wikipedia.org/wiki/FOGBANK)

~~~
avs733
Interestingly...the first portion of the weekly standard article seems to
pretty clearly match wikipedia.

I'm wondering who is plagiarizing whom?

~~~
borkt
See the references in the wikipedia article. Article came first it appears.

------
atemerev
I am pretty sure it is not aerogel. The material has to be transparent for
neutrons, lightweight, and immediately vaporizable to create radiation and/or
ablation pressure. Styrofoam fits the bill; usual aerogels do not.

From what I know about the Stockpile Stewardship program, they had
difficulties in recreating the exact composition (including impurities) of
many weapon components, probably including the interstage — because the only
way to make sure that new weapons and their replacement parts will work
without tests (which are now banned) is to recreate everything to the smallest
detail. So the problem is not manufacturing some exotic material, but
recreating the exact composition and impurities.

~~~
XMPPwocky
This is a good point- imagine having to recreate, exactly, plastic foam
manufacturing processes from decades earlier. How much shop tradition- "oh,
yeah, the official design says we do this, but Bob over there figured out a
clever trick that saves a lot of time and now we all do it instead"\- might
you have to track down or rediscover?

------
dang
Related from 2017 and 2010:

[https://news.ycombinator.com/item?id=15331731](https://news.ycombinator.com/item?id=15331731)

[https://news.ycombinator.com/item?id=1928233](https://news.ycombinator.com/item?id=1928233)

------
ggm
shame they didn't stockpile but I guess once you start stockpiling, its
admitting you didn't mean to do START after all.

------
EdwardDiego
> So what is Fogbank, anyway?...

>...But all of that hardly matters

Considering I felt compelled to read most of the article to find out what it
is, I disagree. Just tell us upfront already.

~~~
mberger
Its a 0/2 flying wall that can't take or deal combat damage. What more do you
need to know?

~~~
thedrexster
I signed up for an HN login to tell you how much I enjoyed this comment,
brother.

------
smitty1e
Recalls Steven Wright:

"He told me that he had spent most of his life working on a research project
for the government trying to find out

who financed the Pyramids.

He worked on it for 30 years, and they paid him an incredible amount of money.
He told me he was pretty sure it was a guy named Eddie."

[https://jjkentala.typepad.com/blog/2010/01/steven-
wrights-19...](https://jjkentala.typepad.com/blog/2010/01/steven-
wrights-1986-hbo-special.html)

