Characterisation of underwater shock parameters in shallow and open water conditions

Understanding pressure propagation in shallow seas has a major impact on ensuring safety during coastal munitions clearance. Simple mathematical formulas are used to determine the 2D hazard area when considering underwater shock, cavitation, and bubble parameters in open water. However, the influence of the explosion depth can make a significant difference to the loading in shallow water conditions. A series of small-scale underwater explosive tests were undertaken to investigate the behaviour of underwater shock waves, focusing on shallow and open water conditions. Test-to-test consistency and repeatability were considered when focussing on key blast parameters of pressure, impulse and arrival time. A bespoke manufactured frame was designed to connect the explosive charge to a sensor array for accurate distance and depth measurements, the results of which are compared to open water recordings both recorded within this test series and extracted from published literature. These comparisons show excellent agreement and shot-to-shot consistency with empirical prediction tools presented.