What’s That? Transmission Visibility Markers

“Look up in the sky! It’s a bird, it’s a plane, it’s…a giant floating ball!”

Brightly colored balls attached to some transmission lines aren’t just fancy decor–they offer a visible reminder of proper line safety from the air. These visibility marker balls are specifically designed to be noticed by low-flying aircraft and helicopters.

Transmission poles and their lines can extend well beyond 65′ into the air and though lines appear large from ground level, they can be difficult to see from the air, especially in bad weather or at night. Visibility marker balls are an important safety measure around landing spaces or in areas where lines cross canyons.

Most transmission line corridors are tucked well away from potential contact with low-flying aircraft, so you may only spot a few of these around the county.

Visibility marker balls are typically orange, red, yellow, or white and are often between 20 to 36 inches in diameter. They are often made of rugged ABS plastic and clamp like a clam shell around the line or mount directly to the top of a transmission pole.

Each marker ball weighs approximately 20lbs. (depending on size used) and can help slightly reduce wind drag on the large transmission lines. They can also help to protect birds and other wildlife from colliding with lines.

Do you have a question about common (or not-so-common) utility equipment in our region? Let us know! news@jeffpud.org