Precision-Angle Tension-Stabilized (PATS) Anti-Personnel Obstacle Breaching System (APOBS)

The current Anti-Personnel Obstacle Breaching System (APOBS) consists of grenades, equally spaced on a fabric reinforced detonating cord over-braided in a polyester support structure. The APOBS kit contains 45-meters of line charge, a rocket motor to propel the system over the target, and a drogue chute to ensure straight-line deployment. Currently the launch rod for the APOBS rocket is installed at a fixed angle. During set-up on uneven or hilly terrain, Marines are trained to improvise backpack supports to adjust the angle of the launch rod. This SBIR topic would identify a lightweight engineering design solution and tool to identify and set an optimal launch angle for APOBS rocket motor deployment. The optimal deployment of the APOBS grenades is a straight line. Due to rocket motor thrust, drogue chute loads, impulse drag from the rear backpack assembly, environmental conditions, or some unknown factor during deployment, the system sometimes deploys with a transverse wave along the detonating cord. This transverse wave can result in arc, u-shape or loops forming along the detonation cord. These non-straight geometric arrangements of the APOBS after deployment may result in unexploded grenades as the grenades detonate from the rear and front fuzes to the center connector. The purpose of this SBIR topic is to modify the APOBS system to (1) allow variable launch angles that can be optimized based upon terrain, and (2) resolve the shape instability issues that result in non-linear deployments.  The Phase I technical objectives will include: Design an adjustable angle launch rod mechanism. Determine the root cause of the transverse wave instabilities. Design a tension-stabilizing solution for the transverse wave instability. Demonstrate the feasibility of design changes in terms of function, manufacturability, packaging, and ease of use. Develop detailed plan for Phase II effort.