entering the earth and traveling toward a deeply buried and hardened target 202 comprising metal or concrete overburden 210 covering a multi layer bunker having horizontal floors the figure shows four explosions 222 224 226 228 which have taken place at four different vertical locations corresponding to time delays designed into the pattern of warhead explosions explosion 222 corresponds to warhead 116 of fig1 explosion 224 corresponds to warhead 114 explosion 226 corresponds to warhead 116 and explosion 228 corresponds to warhead 110 the vertical explosion pattern shown in fig2 is significant in that it provides the penetrating weapon 100 with a greater probability of target destruction than a penetrating weapon which provides a single explosion of higher yield in addition the rearward to forward detonation pattern of the warheads is significant insofar as it enables greater penetration depth of a weapon than is possible by any known weapon providing a forward to rearward i e rearwardly directed pattern of detonations this advantage is due to the fact that as each rearward warhead explodes it acts as a hammer or pile driver impacting on the bulkhead forwardly of the detonated warhead to impel the remaining portion of the weapon forwardly in the direction of the.