WorldWide Drilling Resource

9 JULY 2021 WorldWide Drilling Resource ® Let’s Have a Blast! Adapted from Information by Mine Safety and Health Administration & Office of Surface Mining Reclamation and Enforcement Electronic and electric may be mistaken as identical, but there is a tricky little syllable “on,” which makes all the difference. Having a blast and doing it safely means being in charge of the “on” part rather than chancing it. Serving the same function and looking similar do not mean detonating devices are equal in safety. Electric and electronic detonators have key differ- ences to consider before using them for blasting. Before choosing an initiation system, determine the numerous site-specific factors. Follow manufacturer recommendations and evaluate rock properties, criteria for vibration, airblast, fragmentation, explosive performance, and borehole conditions, such as water, voids, or weak walls. Then study the key differences between electric and electronic det- onators so the blast comes “on” when planned rather than being a dangerous “surprise”. The lead wire attachment is configured differently. Electronic detonator wire leads do not attach directly to a match head or bridge wire. However, electric detonators do have a direct connection and are susceptible to initiation from static, stray current, and/or radio frequency energy. Reliability of control is the difference here. Other protections for electronic detonators against extraneous energy sources include: a spark gap device against static discharge events (high voltage spikes from static buildup on personnel and equip- ment) and current-limiting resistors. Electronic devices are also the only ones designed to provide password protection, pro- gramming capability, and the energy levels needed to charge them in a circuit and send a fire command. Both electric and electronic initiators can be damaged by electromagnetic pulses or pressure, but the likelihood of dam- age is less with electronic devices. They generally have built-in protection from extraneous energy and are designed with microchip technology for timing and firing control. Interchangeability is another major difference. Electric detonators can be used with any appropriate firing device. However, unique electronic detonating systems and components must never be interchanged. Because manufacturers have developed their own systems, the devices and accessories are specifically designed for each manufacturer. Electronic blast-initiation systems increase security, design flexibility, and control, but are also more complex, so more operator training is needed. No matter which system is used, always follow best practices. Clear the blast area of personnel, vehicles, and equipment before connecting to the firing device or blast controller. If you are going to have a BLAST, do it SAFELY! EXB Photo courtesy of U.S. Army Corps of Engineers. tĞůů WƌŽĚƵĐƚƐ tĂƚĞƌ ^ǁŝǀĞůƐ ^ĂĨĞƚLJ ,ĂŵŵĞƌƐ Θ ƌŝǀŝŶŐ ƋƵŝƉŵĞŶƚ ^Žŝů ^ĂŵƉůŝŶŐ ZŽůůĞƌ Θ ƌĂŐ ŝƚƐ WƵŵƉƐ Θ WĂƌƚƐ ƌŝůů ZŽĚ Θ ĐĐĞƐƐŽƌŝĞƐ ŽƌĞ ŝƚƐ Θ ĐĐĞƐƐŽƌŝĞƐ ŽƌĞ ĂƌƌĞůƐ ĂƐŝŶŐ ƵŐĞƌ ƋƵŝƉŵĞŶƚ ĚĂƉƚĞƌƐ 4"-&4!//%3*-*/( $0. 888 //%3*-*/( $0. '"9 1)0/& 64" / / %SJMJOH 4VQMZ .BOVGBDUVSFS 36/4 %&1 063 26"-*5:

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