This is an interesting peace of munition.
Penetrating bombs use physics to go deep. As they are heavy and aerodynamic, they gain incredible speeds during their downward flight. A bomb like this can reach speeds of 500m/second (1.2-1.3 Mach) when it hits the ground as dictated by terminal velocity laws.
They rotate like a screw and their sharp nose goes through layers of rock and earth. But to have gone through 90 metres of earth is an unbelievable achievement.
They are most effective if they don’t penetrate the bunker as the shock wave of such an explosion in dense layers will create an effect similar to a torpedo exploding a metre or two below a destroyer. Because of this they are also called earthquake bombs.
How trustworthy is this newspaper is a question but;
Türk savunma sanayii, İran’ın nükleer tesislerine hayalet uçak B-2’lerle “sığınak delici” bombalar bırakan ABD savunma sanayiini geçti. 6 tonluk muadillerini 1 ton ağırlığı ile geride bırakan Hayalet Nüfuz Edici Bomba (NEB) yerin 90 metre derinliğine ulaştı.
www.turkiyegazetesi.com.tr