260ft is around 79m. The bombs can penetrate around 60m of concrete. So one bomb, probably not, but they are able to follow each other in quick succession meaning 2 or three should be able to do the job quite easily, with accurate GPS positioning.
They can penetrate 60m of soil. They cannot penetrate 60m of concrete. Reinforced concrete at about 5000psi would only get penetration of 8-15m.
The facility is beneath 80m of limestone which in the Qom formation is roughly equivalent to about 5000psi concrete.
Beneath the limestone, sits the facility itself which is encased in high performance concrete. So these bombs need to pen 80m of 5000psi material and then a unknown depth of high performance concrete.
There is no public information about what kind of material 60m refers to, and the best guesses of reinforced concrete are 18m. https://en.m.wikipedia.org/wiki/GBU-57A/B_MOP While a single bomb would be insufficient, you don't need that many to get to 80m.
And US military assets are often much more powerful than publicly advertised...
A bomb penetrating 18m of reinforced concrete doesn't excavate 18m of concrete. It would weaken it by some percentage through fractures and overpressure but you'll need to pen it again with the second bomb.
According to the pentagon briefing this morning they dropped 14. News is reporting that it was in 3 specific locations and they were dropped successively. Assuming most detonated successfully, that much specialized ordinance did some damage. This bomb was specifically designed for this very purpose and you have to realize that capabilities that are reported are probably pretty conservative vs what the bomb is actually capable of doing.
I know a bunch of armchair generals on here are speculating that this was ineffective, but time will tell.
Because it’s always the case with the US military equipment capabilities that full capability is never disclosed. What possible reason would the military have in divulging actual specs?
Military: We can penetrate up to 200 feet with this new bunker buster bomb that we spent a billion dollars on…specifically for this site and some sites in North Korea.
Enemy: Build the bunker at 300 feet, I hear their best bunker buster is only effective to 200 feet.
Also, surely – I have no expertise – but you don't need to totally destroy the bunker to render the operation basically dead, right?
The land, roads, ingress points, elevators, security, everything around here is now FUBAR. Okay so you didn't "destroy the bunker", but how many years until it's functional again?
you don't actually need to completely destroy all the underground levels in Fordow. It is enough to cause enough damage so that the stored uranium contaminates the site, while being sealed from the outside world under the collapsed site.
The point is not to dig a hole. Penetration depth is a function of compression strength of the medium. Every bomb leaves a path of debris in its wake with negligible compression strength that subsequent bombs can pass through before expending their energy.
There were an estimated twenty of these bombs in existence before the bombing; very little head room for throwing more of them down the hole if they haven't done the job.
