Have you ever looked up at the sky and seen brightly colored balls hanging from powerlines?
You might have pondered what they do or why they’re there. These intriguing signs,
known as aerial marker balls, perform an important role in guaranteeing the safety
of both airplanes and people on the ground. Let’s take a closer
look at why these multicolored balls are so frequent along electrical lines.
Using Visibility Markers for Sky Navigation
The colorful orbs that adorn electricity lines are more than just ornaments;
they are strong indicators that help keep our skies safe. These markings,
also known as visibility markers or aerial marker balls, have a special purpose:
they notify low-flying aircraft to the presence of electricity wires.
Think of them as small signals that direct pilots away from potential risks.
Staying Out of Danger
Consider a scenario in which an airplane is flying at low altitude, potentially near canyons,
lakes, rivers, or airports. In such cases, the aircraft may collide with power lines that are not
immediately apparent. To prevent this, the Federal Aviation Administration (FAA) requires the placement
of these aerial marker balls on power lines that traverse regions with low-flying aircraft activity. By installing these indicators, we make the area safer for both aviators and individuals on the ground.
Colors that catch the eye
Have you ever wondered why marker balls come in a variety of colors? The solution rests on increasing visibility. The colors used—often orange, white, and yellow—are carefully chosen to contrast with varied settings. When flying across the sky, pilots want markers that are impossible to overlook. These bold colors ensure that the markings stand out and warn them to the existence of electrical wires.
Remarkable Material: Plastic.
You might be wondering what these marker balls are made of. Surprisingly, they are made of plastic. This choice of material is both practical and strategic. Plastic does not conduct heat or electricity, making it a great electrical insulator. This attribute ensures that the marking balls do not interfere with the power lines’ functionality while also improving safety.
From Size to Weight: Technical Details
Marker balls come in a variety of sizes, usually ranging from 20 to 36 inches in diameter. Despite their diminutive look, they weigh between 11 and 17 pounds. This mix of size and weight enables them to be conveniently fastened to electricity lines while staying durable and wind-resistant.
Origin of Marker Balls
The backstory underlying these colorful markers is as intriguing as their usefulness. An occurrence occurred over 50 years ago, in the early 1970s, which prompted their construction. Winthrop Rockefeller, the then-governor of Arkansas, was on an airplane with Edward Holland, the chief of the Arkansas Department of Aeronautics. As the jet dropped, Rockefeller observed electrical lines in perilous proximity to the aircraft.
Concerned for the safety of both pilots and passengers, Rockefeller pressed Holland to find a way to make power wires more visible to aviators. Holland, in turn, approached engineer Jack Rutledge to take on this job. Rutledge’s clever idea involves creating bright, highly visible marking balls that could be affixed to electrical lines without being easily dispersed by wind.