14 Apr 2023

Live-Fire Validation of Command-Detonation Residues Testing Using an 81 mm IMX-104 Munition

Abstract: Postdetonation energetic residues can have environmental impacts that present a risk to military training-range sustainment. As munitions with new explosive formulations are developed and fielded, quantitative methods for assessing their residues are needed. Command detonation (i.e., static firing) allows residue testing to occur early in the acquisition process; however, its representation of live-fire residue production is uncertain due to differences in the initiation mechanism and cartridge orientation. This study aims to validate residue testing by command detonation through statistical comparison of residue deposition rates between live fire and command detonation. Live-fire residues were collected from fourteen 81 mm IMX-104 mortar cartridges fired onto snow, and deposition rates were compared with previous command-detonation tests of the same munition. Average live-fire deposition rates were 8000 mg NTO (3-nitro-1,2,4-triazol-5-one), 60 mg DNAN (2,4-dinitroanisole), 20 mg RDX (1,3,5-trinitroperhydro-1,3,5-triazine), and 2 mg HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocane) per cartridge. Compared to command detonation, live fire of the study munition produced significantly greater residues of NTO (p < 0.0001) and RDX (p = 0.01) but not DNAN (p = 0.067). Although absolute deposition rates of some IMX-104 compounds differed, command detonation was successful at predicting the order of magnitude of each IMX-104 compound for the studied 81 mm munition.

28 Dec 2021

Fort Huachuca Ranges: A History and Analysis

Abstract: Fort Huachuca Environmental and Natural Resources Division (ENRD) sent funds to ERDC-CERL to develop a historic context that assists Fort Huachuca personnel in identifying the likely history and provenance of numerous historic range features located across Fort Huachuca's training lands. The historic context will be used by cultural resources personnel to evaluate and manage the resources appropriately. Various historic training range features (e.g., structures, fragments, and items left over from previous activities) are located across the ranges of Fort Huachuca, representing its long and storied history. To help identify and catalog these features, ERDC-CERL conducted a field survey of the training ranges in 2016 in or-der to photograph the historic range features. Forty-one historic range features were identified. Researchers conducted archival research, literature reviews, and image analysis of historic and current maps and photographs to identify the 41 historic range features and place them within a chronological context of Fort Huachuca's training ranges. The report concludes with guidance on how to identify and associate sites and features within the overall historic training range chronology and evaluate them appropriately for significance and National Register of Historic Places (NRHP) eligibility.

30 Sep 2021

Determination of Residual Low-Order Detonation Particle Characteristics from IMX-104 Mortar Rounds

ABSTRACT: The environmental fate and transport of energetic compounds on military training ranges are largely controlled by the particle characteristics of low-order detonations. This study demonstrated a method of command detonation, field sampling, laboratory processing, and analysis techniques for characterizing low-order detonation particles from 60 mm and 81 mm mortar rounds containing the insensitive munition formulation IMX-104. Particles deposited from three rounds of each caliber were comprehensively sampled and characterized for particle size, energetic purity, and morphology. The 60 mm rounds were command-detonated low order consistently (seven low-order detonations of seven tested rounds), with consumption efficiencies of 62%–80% (n = 3). The 81 mm rounds detonated low order inconsistently (three low-order detonations of ten tested rounds), possibly because the rounds were sourced from manufacturing test runs. These rounds had lower consumption efficiencies of 39%–64% (n = 3). Particle-size distributions showed significant variability between munition calibers, between rounds of the same caliber, and with distance from the detonation point. The study reviewed command-detonation configurations, particle transfer losses during sampling and particle-size analysis, and variations in the energetic purity of recovered particles. Overall, this study demonstrated the successful characterization of IMX-104 low-order detonation particles from command detonation to analysis.

10 May 2021

The Effectiveness of Laser-Induced Breakdown Spectroscopy (LIBS) as a Quantitative Tool for Environmental Characterization

Abstract: Laser-induced breakdown spectroscopy (LIBS) is a rapid, low-cost analytical method with potential applications for quantitative analysis of soils for heavy metal contaminants found in military ranges. The Department of Defense (DoD), Army, and Department of Homeland Security (DHS) have mission requirements to acquire the ability to detect and identify chemicals of concern in the field. The quantitative potential of a commercial off-the-shelf (COTS) hand-held LIBS device and a classic laboratory bench-top LIBS system was examined by measuring heavy metals (antimony, tungsten, iron, lead, and zinc) in soils from six military ranges. To ensure the accuracy of the quantified results, we also examined the soil samples using other hand-held and bench-top analytical methods, to include Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and X-Ray Fluorescence (XRF). The effects of soil heterogeneity on quantitative analysis were reviewed with hand-held and bench-top systems and compared multivariate and univariate calibration algorithms for heavy metal quantification. In addition, the influence of cold temperatures on signal intensity and resulting concentration were examined to further assess the viability of this technology in cold environments. Overall, the results indicate that additional work should be performed to enhance the ability of LIBS as a reliable quantitative analytical tool.