[Adder]

Can anyone explain how this bomb penetrates 9 meters of reinforced concrete...roughly 27 feet thick and laced with steel bars probably 6"-12"oc each way? Even with a steel hardened tip? How does it work?

[Blueflag]

5000 lbs times 500+ feet/sec impacting on (est.) 1.5 sqft = 2,500,000 ft-lbs/sec. roughly 13,000 foot-lbs per sec per sq inch.

mass time velocity with a penetrator tip. Think anti-tank sabot round made really large for concrete and vertical insertion.

[El Gato]

Can anyone explain how this bomb penetrates 9 meters of reinforced concrete...roughly 27 feet thick and laced with steel bars probably 6"-12"oc each way? Even with a steel hardened tip? How does it work?

It's mostly an old artillery tube. Most of the weight is the steel of that tube. It's dropped from fairly high altitude, and doesn't have much air drag, so it's moving very fast when it hits the surface. Sheer momentum, and a fairly small frontal area to apply all that force on, carries it through the concrete, bending the re-bar aside as it goes. Then it explodes the ~650 pounds of tritional it carries, which does finally blow up the tube, along with whoever or whatever might be in the general vicinity. Even if it didn't explode, it would still make a mell of a hess.