#Truth is: Risk = probability x consequences
Sweetnam implies that the risk of a flyrock incident is effectively zero. But data from the international blasting contractor, Dyno Nobel, indicates that the probability of flyrock is about 0.5%, low but not zero.
But risk is probability x consequences and the consequences are often catastrophic. Responsible quarry operators acknowledge that the only protection from flyrock is to provide safe setback from the blasting site to ensure that no flyrock damage or injury occurs, and there are at least two methods used internationally to calculate a safe setback.
JDCL made a faulty calculation using one of these methods, and defined a setback determined that is one-quarter of what it should be if the method had been properly applied.
Don’t put your safety in their hands.