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When two pieces of heavy equipment interact, jolting and jarring can occur. During haulage truck loading for example, there is a chance that the operator of one or both pieces of the equipment will experience jolting and jarring. Additionally, a jolt can occur when an off highway equipment operator drives over a road defect or inadvertently strikes a berm. Aside from the operators, there is seldom anyone else that witnesses the interaction and can accurately describe the extent of the jolting. This makes it difficult for health and safety managers to address jolting and jarring. The devices and software described in this paper constitute a method for installing “black boxes” called Shox Boxes onboard equipment that already have a GPS system onboard. The resulting configuration provides an objective assessment of jolting and a chance to determine the root causes of it.

A state-of-the-art, characteristic-based upwind, interface capturing multiphase gas-liquid numerical formulation has been utilized to shed insight into the complex physics that characterize premature fuel nozzle shut-off during a typical refueling event. Interactions amongst several sub-processes are entailed which occur over widely different length and time scales. Detailed numerical simulations indicated that the physics is governed by: a) transient flow in vent and fill pipe during fuel nozzle shut-off; b) multiphase interactions at fuel/air/vapor interfaces and entrained air bubbles in fuel; c) formation of boundary layers in vent pipe and boundary layer displacement effects on wave propagation; d) formation of “vena contracta” at entrance to vent pipe; and, e) strong dependence of acoustic speed upon level of dissolved gases.