Which piece of safety equipment is essential for linemen while working on power lines?

The essential safety equipment for linemen while working on power lines includes hard hats and safety harnesses. Hard hats are crucial for protecting the head from falling objects or impacts, which are common hazards in electrical work. A safety harness is equally important as it secures the lineman while working at heights, preventing falls, which can be life-threatening.

Linemen often work on poles and towers where the risk of falling is significant. The combination of hard hats and safety harnesses ensures that they have both head protection and fall protection, making this selection the best answer for ensuring their safety in high-risk environments. Other options such as heavy-duty work boots, although important for footwear, and high-visibility jackets, which enhance visibility, do not provide the same level of critical protection as hard hats and harnesses do in specific lineman operations. Respirators also serve useful purposes in certain environments but are not a primary necessity when working directly on power lines.