Lightning

Lightning is a hazard to both surface and underground blasting. Should a lightning bolt strike the blasting circuit, a detonation would most probably result with either electric, non-electric or electronic initiators. The probability that a direct hit would occur is remote, but a lightning bolt striking a faraway object could induce enough current into an electric circuit to cause a detonation. The danger from lightning is increased if a fence, stream, or power transmission line exists between the blasting site and the storm. Underground blasting is not safe from lightning hazards since induced currents large enough to cause detonations can and have been transmitted through the ground. All blasting operations should cease and the area should be guarded when a storm is approaching. Commercially available lightning detectors can be purchase in areas where electrical storms are common. Lightning Detectors are required on every construction project where blasting is required. . Equipment must be equivalent or better than the Safety Devices Model SD-250 Elk 11 (Figure 31) or the SkyScan EWSP EWS-PRO lightening detector (Figure 32).