Energetic Residues Deposition From 60-mm and 81-mm Mortars

Abstract

Military live-fire training missions utilize a variety of energetic materials that are never completely consumed during firing. Many munitions are issued with various types, quantities, and configurations of propellants. In January 2006, CRREL teamed with the 1st Battalion, 501st Parachute Infantry Regiment (PIR) in Alaska to sample areas used during a mortar training mission. Samples were collected from the snow surface at the firing points for both 81-mm and 60-mm mortars, as well as from areas up to 50 m downrange. Test burn points, areas where 10 excess propellant charges were burned, also were sampled. Six plumes comprising seven detonations of 60-mm high-explosive rounds were sampled on the impact range. Samples were analyzed to derive an estimate of the mass of unreacted energetics deposited from each activity. The 81-mm firing point contained 64 g of NG (3.3% of original NG mass). The 60-mm firing point contained 2 mg of NG (0.65% original NG mass), while the 60-mm impact plumes had a median of 50 mug RDX (2 10 (-5 exp %) of the HE load). Burn points had 840 mg, 1.6% of the original NG mass. These results indicate that further investigations of firing points are critical and that action needs to be taken on burn points.