Information on Mortars
The BPA are aware of very varied practices in the way fireworks, and particularly mortars for shells, are rigged by companies in the UK (and indeed around the World).
The BPA made the decision when developing its training courses NOT to dictate the way mortars or mortar racks should be designed, constructed or rigged, instead relying on the expertise and customs developed by companies themselves alongside suitable and sufficient assessment of the risks involved (including how the mortars or racks would be supported on various surfaces).
However recent incidents and enquiries from members of the BPA have encouraged us to reiterate some general principles which we hope you will find helpful.
- Mortars should be constructed from materials that will be strong enough to contain the lifting charge of shells
- They should be designed in such a way that if a shell bursting charge explodes while the shell is within the mortar that the effects are contained, or that the risk from fragmentation is low
- Mortars should be regularly checked to ensure that the structural integrity is maintained and that they remain fit for purpose
- Single mortars should be erected on site in such a way that failure of one does not affect adjacent mortars and that any failure is “fail safe” such that fragments are contained or prevented from reaching persons (operators or audience) and that mortars cannot fall towards the audience or other vulnerable areas of the display site
- Where mortars are arranged in racks these should be constructed in such a way that the failure of a single mortar does not cause adjacent mortars to be disrupted
- Racks should be supported in such a way that they remain upright (or at the desired angle) when firing and that disruption of a mortar within the rack, or adjacent to the rack, does not lead to mortars being disrupted and potentially firing towards the audience or other vulnerable areas of the site
- Fusing of shells to be fired from racks should be done in such a way as to minimise the risks of one shell disrupting adjacent mortars and a subsequent mortar discharging at an undesirable angle.
After recent incidents we believe that the investigating authorities will in the future ask the following questions, and you should ensure that you can provide the necessary answers:-
- What risk assessments were carried out as to the design, construction, rigging and firing of shells and what mitigatory measures (if any) had been identified to ensure that the risks were as low as reasonably practical (or less)
- In the case of mortars and racks – what tests or evidence from suppliers was obtained to ensure that the risk of failure was low
- What quality assurances had been done on shells to be fired from the mortars – in order to minimise (or at least quantify) the risk of catastrophic failure
- How were mortars and racks checked to ensure they were still “fit for purpose” and had this checking been documented for the mortars in question
- If there had been a change in techniques – rigging or firing – had the risks of the change been assessed
- How had operators on site rigged the shells – were they following company procedures
- What procedures were established (and documented) for various situations, and how had this information been given to operators (ie training)
Fireworks do fail – what is essential is that companies recognise this and take steps to ensure the consequences of any such failure and the rate of failure are low. Ultimately the Courts may decide that whatever you did to minimise risks was not enough – but we strongly believe that if you can demonstrate a very clear understanding of the potential risks and have taken steps to minimise such risks – then the likelihood of a prosecution following an incident is reduced, and the consequences of a successful prosecution (eg the fine or prison sentence) are also reduced.