Net explosive quantity

Abstract: : When 12-inch concrete substantial dividing walls are used to protect personnel from explosive effects, the typical allowable explosive weight, when calculated using the methods in Army TM 5-1300, is less than 2 pounds TNT. Comparison of results from state-of-the-art nonlinear finite element models to actual data from accidental explosions shows that even well validated, high fidelity, physics-based analytical methods grossly overpredict the response of these walls. Consideration of the observed damage from these accidents indicates that methodology used to compute the gas pressure portion of the blast loads incorporates significant levels of conservatism. Further analytical and experimental investigation to reduce this level of conservatism could allow up to an order of magnitude increase in the allowable net explosive weight for personnel protection.

Abstract: To determine the airborne emissions that occur when conventional munitions are destroyed by open burn/open detonation (OB/OD), munitions shots were carried out in a large underground (4650 m3) chamber. Carrying out the tests in a chamber allows the total emissions to be measured, which is not possible in open-air testing. We report here the development of an instrument to measure the time-dependent mass concentration and aerosol size distribution of respirable aerosols (< 10 μ m) from detonations of artillery projectiles in the underground chamber. The instrument incorporates an on-line diluter and real-time cascade impactor for aerosol monitoring. Design, flow modeling, construction details, and results from the instrument are given. Particulate emissions from detonations of twenty four 155 mm artillery projectiles, with a total of 377 lbs net explosive weight, were monitored. Aerosol measurements from the two duplicate tests were very similar. Aerosol mass concentrations showed rapid decreases from 37,0...

Abstract: : Tests have been conducted to determine the TNT equivalency of selected U.S. Army gun propellants. These tests examined M1, M6, and M30A1 propellants. The tests utilized relatively large stacks of material (Net Explosive Weight on the order of 2000 pounds). The tests were conducted by placing the material inside a heavy-walled concrete pipe. Airblast was measured outside the structure. Equivalent yield and TNT equivalency were determined from the airblast. All three materials exhibited energetic reactions which approached a detonation and gave yield approximately that of an equal weight of TNT.

Abstract: In this paper we utilized an additional forward model to estimate the detonation depth using normal modes (cutoff frequencies) to estimate the detonation depth and net explosive weight. With detonation depth the net explosive weight for a shallow underwater explosion could also be determined. The hydroacoustic wave propagation in shallow channel was confirmed via ray-tracing method. We found cutoff frequencies of the reflection off the ocean bottom to be 8.5 Hz, 25 Hz, and 43 Hz while the cutoff frequency of the reflection off the free surface to be 45 Hz including 1.01 Hz for the bubble pulse, and also found the cutoff frequency of surface reflection to well fit the ray-trace modeling. Our findings led us to the net explosive weight of the ROKS Cheonan to be approximately 136 kg TNT at a depth of about 8 m within an ocean depth of around 44 m.