Improvised explosive devices: Pipe bombs

The fragments from 56 pipe bombs were collected (average recovery 87%), counted, weighed, sorted, and photographed. The matrix examined included eight energetic fillers, two initiation systems, three types of pipe, and several degrees of fill. The matrix and results are summarized in Table 1. For identical devices, the overall fragmentation pattern was surprisingly reproducible. The fragmentation patterns are presented in photos, but they are also reduced to numerical evaluators. A particularly useful evaluator is the fragment weight distribution map (FWDM) which describes explosive power with a single variable-the slope. This value is independent of device size and percent recovery. We believe this database of 56 pipe bombs is the largest controlled study of these devices. This study demonstrates the possibility that, even in circumstances where chemical residue cannot be found, sufficient evidence is present in the pipe fragments to identify the nature of the energetic filler.