Electronic Detonators: Should they come with training wheels?

My opinion of electronic detonators has changed greatly over the last few years. As a relatively young engineer, I love anything that is digital and new. Why would anyone fax something when they can email. Why use non-electric systems when there are electronics? And det cord? What is that? Electronic dets can be a highly specialized tool and can be used to improve many aspects of a drill and blast program. However, just as email allows us to accidentally and sometimes catastrophically “reply all”, electronics can make it very easy to deliver unwanted results in blast. The high reward that is promised with electronics comes with high risk.

Please consider the following worst case scenario:

A site fully switches to electronic timing and therefore sells back all non-electric systems. A full conversion offers a lower price per det and can be more attractive. Training and mentoring is then supplied to the drill and blast team on site. Once things begin to run smoothly, mentoring is no longer needed and the site runs sufficiently. Before long, it is time to rotate engineers and therefore time to bring in a new, and typically inexperienced, drill and blast engineer. A short handover is given and the new engineer is free to use any of the infinite timings available with the system. About 99% of these timing options should never be used. The new engineer will now get creative and apply a timing that sends all of the energy in the wrong direction, is too fast, too slow, or just plain wrong. The senior engineer reviews the timing but doesn’t fully understand the system and approves. A non-ideal timing is now issued to the shot firers who are now used to the system and comfortable with the engineering support. There is no indication of a problem in the field since the shot firer only sees copper wire and a list of holes and their delay times. It can be difficult to get an idea of how the timing behaves without an animation or timing contour map. The shot firer does not receive either. When it is time to fire, the shot firer goes through all of the necessary safety checks with the system and is cleared to fire. Upon firing vibration is exceeded, fragmentation is poor, there is back break into the highwall, and flyrock is thrown out of the exclusion zone. Worst case indeed. This case assumes all holes are labeled adequately and receive the correct det sequencing which can be another issue.

The case above is one that happens too often with electronics. The cost of such incidents can easily offset any savings that the system may bring once (or should I say if) it is optimized. With that said, very few sites have been able to effectively measure the cost savings after switching. I am not saying they don’t exist, I am simply saying they are hard to measure and compare with confidence.

With all of that said, electronics can be quite brilliant for the experienced user. The question is how do we create an experienced user in a safe an controlled manner i.e. without incident. Is there a way to offer electronics with limited timing options? Is it worth keeping non-electric dets for training purposes and shallow, less complex shots? Can site specific electronic timing intervals be offered in a way similar to non-electrics? Should the design software have locked features for beginners?