Which of the following is the most important safety consideration when servicing and underground electrical transmission lines?

• A. There must be at least 2 people making the visit
• B. The power must be terminated during the visit to prevent electrocution
• C. A gas mask must be used at all times
• D. The truck should be parked close enough to hear the radio

Answer: (B)

De-energizing and isolating the line before any work begins is the top safety priority. If the underground transmission line remains energized, even a small contact or unexpected movement can cause fatal electrocution, arc flash, or dangerous faults. The proper approach is to turn off the power, apply lockout/tagout so it cannot be re-energized, and verify there is zero energy in the circuit and equipment before starting work. This ensures workers aren’t exposed to live voltage, including stored energy or backfeeds that can keep the line dangerous even after it’s supposedly off. Use the right personal protective equipment and follow site procedures after confirming zero energy.

Other practices are helpful but do not address the core risk of electric shock: having another person present or proximity of the vehicle doesn’t guarantee safety from energized lines, and a gas mask is not relevant for electrical service work.