National Museum of Nuclear Science & History

I’ve seen the signs before but haven’t ever seen this museum. I decided to come down off the hill a day before my van service; this would allow me to stage near the dealer for a 7am slot and also see the museum.

General Admission is $15, and $8 for veterans with ID.


Fermis's gear lego CP-1

There were several models and artifacts from Chicago Pile 1; these caught my attenton.

  1. some of Enrico Fermi’s instruments from the lab
  2. an amusing lego model of CP-1
  3. one of the exterior graphite blocks from the pile (in the case with the lego model)


gadget model limo core transport

First we have the obligatory Gadget model. The second pic is a stretched (Packard?) limo used to transport the scientists and VIPs. There was a heavy cloth covering over the roof center – I thought maybe it was a rollback sunroof but the interior upholstery under it was intact. Ornamental? A padded area to rest instruments on when stopped?

The third pic is the (Chevy?) sedan that carried the core to the site in the back seat.

Outside there is a replica of the 100’ Trinity test tower, as the original was… unavailable.

AFAIK this is the only full-scale replica of the tower. I was a little surprised the public is allowed to walk under the suspended load (another Gadget model that appeared to be made of metal).

Fat Man

Normally I wouldn’t have much interest in Fat Man stuff but something about this model caught my attention. I stared at it for a while then realized this was the only model I’d seen in person or in pictures that had what appeared to be antennas mounted on the raised pads. I asked the docent what they were but he didn’t know. He added that the antennas were best-guess because the originals were never publically documented.

I later found this WSMR page that says:

Around the middle of the casing are spots for mounting four radar antennas. The bomb was designed to explode above the ground for maximum blast effect. The radar would trigger the bomb at the prescribed altitude.

So now we know.

I read a bit further and found these were called Archie antennas as they were for the Archie radar fuse (see below) and were classified until 2015. This order (pdf) declassified:

external physical characteristics of the external Yagi-U do antennas used on nuclear weapons designed and constructed by the United States having such antennas (i.e., Mk II “Little Boy”, “Fat Man,” and Mk Ill nuclear bombs},including war reserve weapons, test devices, ballistic shapes, and mockups

The document also reveals Archie was unmodified APS-13/Monica British technology (300MHz tail-warning radar for bombers).

“Yagi-U do” is an apparent typo for Yagi-Uda. The design appears to be related to this folded dipole patented later. .

This document shows some Los Alamos regulations about Archie:

While all parts of fuzing program are secret, the primary components, Archie and Amos (PMR), are to be considered of a higher order of secrecy. They may be classified as SECRET RESTRICTED and should not under any circumstances be discussed with or in the presence of anyone outside Group O-3 (Author’s note: the LASL bomb fuzing group).

Frequencies on which the above units operate must not be stated verbally or in writing in such a way that they may come to the attention of anyone outside the Group.

Antennas must be kept concealed as much as is practical. When being carried through the halls they must be completely covered.

Visitors should be discouraged, without arousing their curiosity, in any room where Archie or Amos are on display.

Nothing should be done to call the attention of others to the secrecy connected with Archie and Amos

Note: PMR is Proximity Measuring Radar. Andy was a PMR for very low altitudes (tens of feet).

Nazi uranium cubes

This uranium cube was one of the ~640 cubes used in the Heigerloch experimental reactor. They were strung up as shown in this replica

After capture the cubes were taken to the U.S. where most disappeared.

Atomic Cannon

atomic cannon

This is the M65 Atomic Cannon. I had to make a panorama out of three seperate pics because the beast is 85ft long (and weighs 86 tons).

7 cannons exist but only 3 have the “prime mover” vehicles that towed them.

This YT video shows transport, setup, and the only complete test fire (Shot Grable in Operation Upshot-Knothole), which yielded 15kt as expected.

Note that the protection of the soldiers at 9:16 timestamp is limited to a trench. At 9:28 vertical smoke streams are visible. My understanding is that smoke rockets were fired before the blast so air disturbances would show up better on observation cameras.

“The big guns were light on their toes”, LOL.


Snark intercontinental cruise missle

This shapely thing is a SM-62 Snark, the only intercontinental cruise missile. Although it apparently never worked very well it had many interesting features. It had a range of over 6,000 miles and was guided by celestial navigation. It launched off a truck with rocket boosters then flew on a turbojet (hence the scoop). It used elevons (combo aileron/elevators) since it had no horizontal tailfin. It carried the Mark 39 warhead (3.8MT), the same ‘head involved in the Goldsboro broken arrow event.

The Snark lost its mission when ICBM came online.

YT video of the Snark, including some interesting rocket sled test launches. The video calls the Snark “a pilotless bomber”, perhaps to assuage concerns about antiaircraft missles. .

Titan II

I believe this Titan II ICBM is the largest missile/rocket I have ever seen in person. It is 120ft tall when assembled. It was closely displayed with other hardware so I couldn’t back up enough to get a pano.


Another example of my obsession with foxy shapes.

I really love the symmetry of the nose on the B-29 and that greenhouse. The blunt nose wouldn’t survive into the Jet Age but it is a handsome machine.


I found no mention at all of the Pershing I/II systems. They had two opportunities to do so:


  • they have a W61 gravity bomb (left); that system’s stockpile inherited the Pershing II’s W85 ‘heads after the INF treaty was signed.
  • their display on treaties (right) noted the INF treaty eliminated nuclear missles with a range of 500km - 5500km but didn’t name the Pershing program.

This doesn’t surprise me. Even the patch and hat hawkers in the VA lobbies don’t know what Pershing is.

van service

That night I stealthed on a side-street near the Stealership.

As a reminder, the return visit was to fix a code they didn’t fix when the powertrain was still under warranty (59,500 miles). By the time I could return the van had 61,500 miles. The service manager had acknowledged my report of the non-fix at the time.

  • 0700 drop-off. Service guy didn’t seem to care it was something they previously failed to fix, requiring a return trip. I didn’t have a good feeling about this.
  • 0930 sent me a $1100 estimate to replace the oil pump.

The 3.6L Pentastar has a two-stage oil pump. At low RMP it runs lower pressure and at higher RPM it kicks into higher pressure. If it fails LOW the vehicle goes into limp mode to avoid going over the RPM limit where it shifts to HIGH. This didn’t happen. If it fails HIGH we get the code the van popped and I guess it uses sligtly more power to drive the pump at low RPM. If the whole pump is failing (low oil pressure) there is a different code when I did not get. From this I deduce the two-stage pump failed in HIGH pressure mode

On my walk back to the office to talk to them I googled the Promaster forum and there were no other mentions of oil pump failure. The Jeep forums reported some oil pump failures with this engine and code so I assumed the shop was making a reasonable decision to replace the pump. Online comparisons showed oil pump replacements showed cost for this engine in this vehicle to be $600-$700, so if I had to pay for it I’d use an independent shop and save $400.

I went in and reminded the advisor it was something they failed to fix under warranty and the service manager knew this. He said he’d “go to bat for me”. Not holding my breath.

  • 1100 no word. I walked around the complex to see where the van was; it was not in sight so it must be in an enclosed bay. I didn’t want to hope, but the only reason I could think of for it to be taking up a bay was that they were doing the work under warranty – they’d have to get my approval to do it at my cost.
  • 1125 I messaged the advisor asking for status
  • 1225 Service advisor messaged back “I WILL GOODWILL IT FOR YOU WORKING ON IT NOW”
  • 1530 van ready for pickup, no charge

I started the van a couple times right there in the pickup bay to make sure there were no codes; there weren’t. I didn’t have to be in ELP until the 10th so I could stay until it was right, but no need.

I was grateful there was no charge, as my emergency fund already was running low due to having to replace the battery bank. I think they did the ethical thing by repairing it at their cost in this scenario.

next stop El Paso

I was originally intending to head to ELP after picking up the van, but temps are being stubborn there. Still in the 90s, dropping to low 80s on Sunday. So I will head down Sunday morning and pick up my packages Monday. In the meantime I am holed up on the mountains east of ABQ again.

I’ll tread water in ELP (~4000ft) until we get down to ~75F highs in DFW where my family lives. My guess is that will be early November.


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