The concept of precise, accurate timing with Electronic Delay Detonators
(EDDs) was first seriously addressed in the mid-1980s and much was
made of the cheapness and profusion of digital watches in terms of the
likelihood of EDDs also being cheap and easy to produce. Ten years later,
with every major explosives company and many electronics groups
having instituted projects to capitalise on the promise of these devices,
production devices are still to come into general use. In South Africa, Expert Explosives units have been used in most
applications during proving trials and more recently for production
blasting in underground ring stoping and open cast coal. The outcome has
been valuable learning both as to the benefits and technical requirements
for electronic delay blasting, and especially, safety aspects. Examples are
shown of production blasts which utilised the power of EDDs. It is evident that it is not delay accuracy alone which determines the
value of these systems, but the whole robustness, flexibility and ease of
delay allocation when harnessing blast engineering knowledge. Muckpile
movement and shape, fragmentation and vibration frequencies have
shown to be greatly influenced by designs which can be implemented no
other way. The flexibility of a system and the power of the software
controlling it are crucial in capitalising on blasting potential, which lies in
integrating control of blast timing with other developing electronic
Technologies.