Live-fire validation of command-detonation residues testing using a 60 mm IMX-104 munition

Abstract

Command detonation (i.e., static firing) provides a method of testing munitions for their postdetonation residues early in the acquisition process. However, necessary modifications to the firing train and cartridge orientation raise uncertainty whether command detonation accurately represents residue deposition as it occurs during live-fire training. This study col-ected postdetonation residues from live-fired 60 mm IMX-104 mortar cartridges and then compared estimated energetic-compound deposition rates between live fire and prior command detonations of the same munition. Average live-fire deposition rates of IMX-104 compounds determined from 11 detonations were 3800 mg NTO (3-nitro-1,2,4-triazol-5-one), 34 mg DNAN (2,4-dinitroanisole), 12 mg RDX (1,3,5-Trinitroperhydro-1,3,5-Triazine), and 1.9 mg HMX (1,3,5,7-Tetranitro-1,3,5,7-Tetrazocane) per cartridge. Total live-fire residue deposition (mean ± standard deviation: 3800 ± 900 mg/cartridge) was not significantly different from command detonation using a representative fuze simulator (3800 ± 900 mg/cartridge, n = 7, p = 0.76) but was significantly different from command detonation using a simplified fuze simulator (2200 ± 500 mg/cartridge, n = 7, p < 0.01). While the dominant residue compound NTO was broadly similar between live fire and command detonation, the minor residue compounds RDX and DNAN were underestimated during command detonation by a factor of approximately three to seven.

Live-fire validation of command-detonation residues testing using an 81 mm IMX-104 munition

“…Walsh et al 2015), so close replication of a munitions' issued fuze is likely essential for accurate representation of live fire. The results of the live-fire validation with the 60 mm IMX-104 mortar munition, Task 1 of this ESTCP project, were discussed in Beal et al (2022).…”

“…However, deposition rates of the compounds RDX and DNAN were significantly greater by live fire than by command detonation using either of the fuze simulators (Figure 1). Beal et al (2022) hypothesized that differences in these minor residue compounds were caused by an effect of munition orientation on the surface recovery of fine-particle-size residues.…”

“…Successful validation would enable confident integration of this technology into the testing process for new munitions, with the data generated informing acquisition and range managers on potential environmental impacts and risks to training-range sustainment. (Walsh et al 2014;) and live fire (Beal et al 2022). Boxes represent the median and interquartile range, and whiskers represent no more than 1.5 times the interquartile range (IQR) above and below the hinges.…”

“…The methods for sampling, processing, and analysis in this study were identical to those used in Task 1 and reported in Beal et al (2022), which, briefly, were as follows.…”

“…For practicality in setup, tests with both the AFS and CFS used blasting caps to initiate the detonations, and the explosive masses used in these caps are substantially greater than masses used in the issued fuze's safe and arm (S&A) device. Interestingly, the same fuze simulation setups were applied to the 60 mm IMX-104 munition with no significant difference in total residue production between the AFS and live fire (Beal et al 2022). It is unclear whether the blasting cap's increased explosive mass could affect filler mass consumption.…”