Safety of operation for hollow-stem auger rigs is compromised when drilling operations occur within what distance of an electrical line?

• A. 50 feet
• B. 100 feet
• C. 150 feet
• D. 200 feet

Answer: (B)

Overhead electrical lines create a high-energy hazard for hollow-stem auger rigs because the rig’s tall mast, moving joints, and the length of the auger pipe can reach into the space above ground and swing or tilt. If the equipment gets too close, a contact or an arc can energize the rig and strike workers, cause severe burns, or bring the line down. To reduce that risk, a substantial clearance is maintained so that even at the rig’s maximum reach and with wind or movement, there is no chance of contact or arcing. In practice, this safety buffer is large—on the order of a hundred feet—so if that distance can’t be kept, the operation should be halted or the line de-energized or relocated.