R. Guilbeault and E. Contestabile
Abstract: Recoil from fireworks articles often arises as a concern in accident investigations or when fireworks are launched from unconventional locations such as rooftops, or other light building elements such as overhangs, from decks of small bridges or those of barges. In this latter case, the Authority Having Jurisdiction will typically require some assurance that the structure will not be damaged and is sufficiently robust to support the dynamic loads resulting from the function of the firework articles. In this study, it is proposed that such measurements can also be used to evaluate multi-shot devices since; their recoil load history reflects their performance in time and magnitude. Various researchers have, over the last decade, devised means to measured recoil loads. Piezoelectric load cells, which have fast response time, have been used and found to satisfactorily track the fireworks recoil loads. This study presents data obtained using an apparatus in the form of a 25-cm diameter platform. Fireworks mortars or articles are placed and functioned on the platform. The signal from the piezoelectric load cell is recorded by a digital storage oscilloscope. The results indicate that the recoil history can be used to determine inter-shot times, total duration, andrelative launch heights of the effects of the multi-shot article. In addition, defective launches and other modes of failure such as in timing can also be easily identified.
Keywords: multi-shot fireworks, recoil, load cell, RLP, mortar
Ref: JPyro, Issue 25, 2007, pp44-48
(J25_44)
© Journal of Pyrotechnics and CarnDu Ltd
