K. L. and B. J. Kosanke
Introduction: As used in this article, the definition of “manual firing delay time” is the time interval between the manual ignition of the tip of the shell leader delay element and when the aerial shell fires from its mortar. This delay time is of interest in the context of the delay time requirement in the National Fire Protection Association’s Code for Fireworks Displays (NFPA- 1123).
Prior to the 1990 edition of NFPA-1123, the requirement for delay times for the manual firing of shells was that:
“The length of exposed black match on a shell shall not be less than 3 in. (76 mm) …. Also, the delay time between the ignition of the tip of the exposed black match and ignition of the lift charge shall not be less than four seconds ….”
Ref: Selected Pyrotechnic Publication of K.L. and B.J Kosanke, Part 7, (2003-2004), pp 92-95
© Journal of Pyrotechnics and CarnDu Ltd