Experimental Evaluation of the Factors That Influence Cylindrical Water Projection Devices against IEDs

Terrorists usually employ Improvised Explosive Devices (IEDs) to cause maximum damage with a single action, in asymmetric war scenarios. In the counter-terrorism fight, bomb disposal specialists have to combat these instruments by safeguarding their lives, avoiding fortuitous IED explosion, and preserving evidence of the device that could lead to the capture of the perpetrators. Some very effective deactivation tools that combine these features are high-speed water-explosive projection devices. To understand and quantify the impacts of the many factors that intervene in their operation and effectiveness, extensive experimental tests should be conducted. However, Operations Research techniques allow robust results to be obtained by minimizing experiments. This study focuses on the use of Design of Experiments (DoE), with a factorial experiment plan divided into two levels, to analyze the influence of the amount of explosive, the diameter of the device (that is, the mass of water to be projected), the density of the water, the distance at which the IED is located, and the resistance of the inner tube material. Results show that the mass of explosive, the diameter of the device, the interaction of the mass of explosive and the density of the water, and the interaction between the resistance of the inner tube and the diameter of the container have a strong influence on the speed of projected water.