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Improving explosives, blasting competence for supervisors, managers

The main hazard associated with explosives is their chemical energy. The risk is in the likelihood of that energy being released when you do not want it to be, causing serious harm. While the likelihood of unintended detonation is very small, the consequences are large ? explosives can be unforgiving.

Explosives work can be contracted out but the risks associated with doing so cannot. I am delivering workshops for the IQA this month that demonstrate how to manage these risks and to formalise risk management as part of an explosives (risk) management plan, as the law now requires.

For explosives, the IQA runs two workshops: one for shotfirers, the other for supervisors and managers of quarries (especially those who engage explosives suppliers). These workshops are designed to update competence, which is a mixture of knowledge, its application and experience.

These are not courses to gain a shotfirers? ticket or management qualifications but can be used to support required knowledge for these. Attendees could undertake assignments (or learning and assessment activities) on-site as part of recognising prior learning.

{{image2-a:r-w:300}}Explosives management workshops have been held in Coffs Harbour, Hunter Valley, Melbourne, Launceston, Adelaide and Brisbane. One further workshop will be run in Maitland later this month. Handouts are provided and include a chapter of the IQA?s Blue Book on explosives management, a copy of relevant slides and a set of pocket cards relating to explosives management. Workshops are interactive, to respond to the needs of those attending.

The one-day explosives management workshop is based around national blasting units of competence at the Certificate IV and Diploma/Advanced Diploma level (specifically RIIBLA401: Manage blasting operations, RIIBLA402: Monitor and control the effects of blasting on the environment and RIIBLA601: Design surface blasts). Learning objectives include dealing with incidents from supervisor and manager perspectives, blast design and establishing, implementing and maintaining explosives management plans.

It challenges participants to reflect on their current approaches and the need to revise their plan and procedures. For example, workshop participants are encouraged to reflect on how they might have dealt with an incident on their site. Incidents include a shotfirer?s vehicle being destroyed by smoking, reactive ground detonating prematurely, fly-rock caused by low explosives and carrying explosives in pockets of work clothes.

Participants are taken through blast design concepts, the fundamentals of blast patterns, calculating the maximum instantaneous charge and minimising blast impacts on the environment; pocket cards are supplied to help with these. The cards give common limits for blast vibration and air blast over-pressure, plus ways to reduce these ? and there are more ways than you might think. Rules of thumb are used to estimate burden and spacing, plus stemming and sub-drilling.

{{image3-a:l-w:300}}The principles involved in pre-splitting, where shockwaves rather than explosive gases dominate, are also covered. Powder factors for different shots are also discussed. Regrettably, but for obvious reasons, Graham is unable to take explosive samples when he flies, but he has a number of pictures and video clips to help explain the topics.

In the third part of the workshop, Graham takes participants through the systematic management of explosives. The more logical the stages seem, the more memorable the contents of an explosives management plan will be, which is vital for communicating it. Participants are led through the stages of establishing, implementing and maintaining an explosives management plan and some sample procedures and forms (which are included in the Blue Book chapter).

The explosives management chapter has the same structure as other chapters and has been developed for organisations and quarries that have been applying systematic risk management for long enough to understand the need for better information, not necessarily more information. The more consistent the structure, the better the various topics are to integrate. The Blue Book will be useful for sites wanting to review their systematic approach, rather than simply add to their existing approach.

There are other publications to help organisations just starting out on the road to formalising their safety management systems, and the IQA can refer such sites to these other resources. The IQA also runs workshops on developing safety management plans, plus other workshops on refining safety management plans. The Blue Book, now in its second edition, deals with other core risks and the fundamental system elements for quarry safety and health, including leadership, safety culture and change management among more traditional elements such as explosives management. 

Quarries must have competent people, so the IQA is progressive in its education of the science of quarrying, including the use of explosives.

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