More on the Midnight Hammer raid

Probably a bit out-dated now
I mentioned reading an article on Iranian concrete technology in the comments on the BDA column – here is some more on that subject.
On Saturday, June 21, 2025, following a spate of unprecedented aerial attacks that Israel carried out against Iran just days before, the United States joined the war and used bunker-busting bombs to strike three key Iranian nuclear sites and their underground bunkers: the Fordow fuel-enrichment plant, the Natanz nuclear facility, and the Isfahan nuclear technology center.
Other than the leaked DIA preliminary assessment, all concerned on our side consider the raid an unqualified success. Here is some more data:
If history serves as any indication, there is a chance Iran’s underground nuclear facilities could be partially or wholly intact. That’s because up until now, in the quiet arms race between concrete and bombs, the concrete has been winning.
In the late 2000s, for instance, rumors circulated about a bunker in Iran struck by a bunker-buster bomb. The bomb had failed to penetrate—and remained embedded in—the surface of the bunker, presumably until the occupants called in a bomb-disposal team. Rather than smashing through the concrete, the bomb had been unexpectedly stopped dead. The reason was not hard to guess: Iran was a leader in the new technology of Ultra High Performance Concrete, or UHPC, and its latest concrete advancements were evidently too much for standard bunker busters.\
Seems counterintuitive – 30,000 pounds – 15 TONS of high explosive – you would think would take out anything. (Might point out our command center under Cheyenne Mountain is supposed to be able to resist pretty much anything for a while, it was built half a century ago. Would modern weapons like our bunker-busters hurt it nowadays? Hmm…)
While the same general-purpose bombs from the 1990s are being used today, bunker busters had to go through several generations of upgrades. In the early 2000s, the Air Force even developed a special type of steel for the purpose, known as Eglin Steel, in association with steel specialist Ellwood National Forge Company.
Eglin Steel is a low-carbon, low-nickel steel with traces of tungsten, chromium, manganese, silicon, and other elements, each contributing a desirable property to the whole. Eglin Steel is the gold standard for bunker-busting munitions, although in recent years it has been supplemented by new USAF-96 steel, which boasts similar performance but is easier to produce and work with.
Sounds like whatever it hits, it will penetrate, right?
“Concrete is inherently brittle,” explains Phil Purnell, Ph.D., an expert in concrete technology at the University of Leeds. “It is good at being squashed, not being stretched. The weakness is in its tensile capacity and toughness.” Purnell notes that while some modern concrete is actually stronger than aluminum, its brittleness is its Achilles’ Heel, and it gives way by cracking.
However, this changed with the advent of the type of concrete known as UHPC. Previously, a yield strength of 5,000 pounds per square inch (psi) was enough for concrete to be rated as “high strength,” with the best going up to 10,000 psi. The new UHPC can withstand 40,000 psi or more.
Fracture energy is defined as the amount of energy needed to split a material open. The concrete absorbs the incoming kinetic energy of a projectile as it fractures, slowing it right down and stopping it from penetrating. Naturally, researchers have been experimenting with finding the optimal mix of fibers for UHPC.
The article goes into more detail on the evolution of bunker-busting bombs – and of the concrete bunkers we’re trying to kill. Worth noting is that the current evolution of bunker-busters, the MOP bombs used Saturday, are already so big only a U.S. B-2 can carry one. They’ll have to become more effective without gaining much weight, to penetrate lower depths and take out harder barriers.
Gregory Vartanov, Ph.D., of Toronto-based Advanced Materials Development Corp, claims high-grade UHPC is simply too strong for bombs made with existing steels. “Penetrators with monolithic cases made from materials such as … Eglin Steel … cannot penetrate bunkers made from UHPC,” Vartanov notes in a February 2021 piece in Aerospace & Defense Technology magazine, basing his claim on open-source penetration formulas.
And a last comforting quote from the article, about an even more resistant Chinese development called FGCC::
According to Chinese research published in 2021, FGCC resisted penetration and explosion far better than UHPC: “penetration depth, crater area, and penetration damage were decreased greatly by the synergistic effects of high-strength fibers and coarse aggregates.” Popular Mechanics
Extremely interesting non-technical read – check it out.
Category: Iran, Science and Technology
Probably need more articles on speculation of what we don’t know.
Yak, yak, yak, yak, … Every success that the Trump Administration has WILL be poo-poo’ed by the D-rats’ mindless minions in the MSM and especially in snobby-assed academia.
“There are known knowns, things we know that we know; and there are known unknowns, things that we know we don’t know. But there are also unknown unknowns, things we do not know we don’t know.”
Donald Rumsfeld
I don’t know about that.
Okay…here’s the final break down…
And by break down I’m not intending to being funny about this at all. I promice.
But…and this is important…remember when you were a kid, and there was this saying that said; “don’t step on the cracks or you’ll break your mama’s back”? huh? You member that? Well did you ever go out an step on sidewalk cracks when you heared that??????
If you were a good Christian chile you didn’t! So that right there will tell you how solid CHRISTIAN concrete is!
But you can bet your bottom dollar that MOOSLIM concrete, which is obviously the cement of the DEVIL, is not going to be as solid as CHRISTIAN concrete!
So, it goes without saying that, because of this unequal gauge of concreational equality that it should be obvious that the concrete of the satanic Mooselimes of the Iranic Republic of Iran can’t possibly have servived the unmitigated shellacking we just laid down on them this past week.
So there!
And yeah, I bin drinkin’ heavily….so wut?
Having seen up close how Iraqi’s make cinder blocks I’m sure I’ll be impressed with Iranian concrete.
Some of the buildings in Bagram were dirt-filled Soviet ammo cans laid like cinder blocks.
Great concrete evidence which cements the facts Skivvy Stacker
I was glued to the article.
We will have to see Elmer about being glued to the article. Isn’t Elmer the guy that brought and taught new Amatuer radio operators into the radio world.
Soooo… if we filled a bunker-buster with holy water… we’d have a yuge version of the Holy Hand Grenade of Antioch…
According to the briefing held by the Chairman of the JCoS held yesterday, the facility at Fordow has been watched and studied by mission specific officers for over 15 years and the GBU-57 MOP was designed and manufactured SPECIFICALLY to destroy that one facility.
I have more confidence in what our SECDEF and the Chairman are putting out than the speculative fiction people not involved with the actual weapons and facility assessments or the lamestream media citing “anonymous source” leaks have to say on the matter.
Yeah, I heard that too. I am now more inclined to believe the White House assessment. Pretty impressive operational planning.
I’m wondering what the effects of a focused explosive would be like. Think of a 30K lb bomb set up with the hardened penetrator and a 15 ton shaped charge. Instead of a GP explosive this one would be set to send a huge focused jet downward.
Jake Tapper has volunteered to sit in a tunnel and let the US Air Force drop one on him to show how weak they are.
Things aren’t going to be Jake for Jake when the bomb hits and he geta tappered out.
Like I believe anything the press “leaks” is true…
The Pee-tape hoax
The collusion/FISA hoax
The ‘fine people on both sides’ hoax
The ‘suckers and losers’ hoax
The walking slowly down a ramp hoax
The Hunter laptop hoax
…hoax, hoax, hoax…
All of which was pushed, no shoved down our throat by the same of bullshit peddling Dems/RINOs that infest the DC Swamp.
You lost me at “30,000 pounds – 15 TONS of high explosive –”. Maybe you should read up on the weapon system before commenting.
15 Tons of “HE”, “sounds better” than 2000 kilos of AFX 757 and 340 kilos of PBX 114 but the target definitely will know the difference vs say a composition B type.
Also in answer to the Cheyenne Mountain question, it is 2000 feet below a granite surface. There is no known conventional bomb that could reach that depth and it seems unlikely one could be produced with current technology.
The deepest nuclear crater ever made was 320′, so no known nuke could reach that depth either. Fordow was about 300′ so a nuke could have taken it out, with a direct hit.
Muktiple laydown multi-megaton bombs were our solution to deep Soviet command bunkers. Presumably the Soviets also.
Large thermonuke.
Soft-land by parachute.
Earth-shattering kaboom.
A bit of time and wind to allow the debris to settle and the mushroom to wander off.
Large thermonuke soft-lands in the crater.
Repeat until you vaporize the bunker.
We had the B41 at 25MT for such effort. The Soviets had their own “Tzar Bomba” at 50MT partially fueled.
Even a 1MT surface burst weapon digs a usable hole.
Warhead versus armor, long term safe bet is warhead.
As I alluded to before, anything since the Tet Offensive needs to be read as skeptical from the media and triplely so when from opposition media. CNN has an agenda and they are going to push that agenda. Just like when they pushed a Trump Nomination because the idiot Chief Editor believed there was no chance of Trump being elected in the general election. Nine years later the joke is still on them and they are still mad about it. So when; “there is a loud noise and Trump fell down”, that is what they report. It’s a version of the truth to be sure, just an incompetent, incomplete and shaded version of the truth.
If that Iranian concrete is so good, they should be selling it to DOT and their legion of paving contractors.