Have you ever noticed those brightly colored balls on power lines while driving or hiking through the mountains of Texas? If so, you might wonder what they are and why they’re there.
These power line balls, also known as marker balls, are essential to our electrical infrastructure and play a vital role in ensuring aviation safety. This article will examine these balls, their history, and how they work.
- Power line marker balls are colored balls placed along power lines, especially where they cross over canyons, deep valleys, and major freeway crossings.
- The history of power line marker balls dates back several decades. The earliest known use was in Arkansas in the 1970s when Governor Winthrop Rockefeller spotted electric wires outside his aircraft.
- Power line marker balls provide an obvious warning to pilots and others who may encounter power lines. They are painted bright colors like orange, white, or yellow to stand out against the sky and terrain.
What Are Those Balls on Power Lines?
The balls you see on power lines are called marker or power line marker balls. They are typically colored bright orange, white, or yellow. They are placed along power lines, especially where they cross over canyons, deep valleys, and major freeway crossings.
Their major purpose is to serve as a visibility marker for low-flying aircraft, such as helicopters and small planes. The use of colored balls as a visibility marker is required by the Federal Aviation Administration (FAA) to reduce the risk of low-flying aircraft colliding with electrical wires.
When flying at low altitudes, power and transmission lines can be challenging to see—especially against the terrain or the sky’s colors. This is where the brightly colored balls come in. They warn pilots that they need to be aware of the power lines’ presence. These are particularly important around mountain passes and near airports.
These visibility marker balls are made of lightweight materials like plastic and typically weigh around 17 pounds. They can be found at various points on overhead power lines with alternating colors to help pilots differentiate between different sections of power lines.
The History of Power Line Balls
The history of power line marker balls dates back several decades. In the 1970s, the earliest known use of power line marker balls was in Arkansas, where the need for more visible electric wires was prompted by Governor Winthrop Rockefeller’s spotting of wires outside his aircraft.
The head of the Arkansas Department of Aeronautics, Eddie Holland, reached out to Jack Rutledge, an engineer running an unsuccessful fiberglass boat manufacturing plant in Little Rock, for a solution. Rutledge’s innovative “marker ball” idea led to the formation of Tana Wire Marker Co.
Rutledge started with a standard 20-inch ball. Over time, he began producing different sizes, including a 54-inch ball to mark the gorge at the Salmon River Electric Co-Op in Idaho. Various marker ball types were also created to accommodate different circumstances.
For example, special effects with the Northern Lights caused the Canadian government to order unique line markers internally coated with silver beads, which cost $2,500. The U.S. Department of Energy ordered similar ones but with carbon coating at a cheaper price.
In addition to airplanes, highly visible markers have been sold to power companies to prevent boats with aluminum masts from crashing into power lines in the Florida Keys.
Additionally, conservationists in Mississippi found Canadian geese were being killed when they struck power lines during bad weather. So government agencies and conservation groups purchased power line marking balls to keep the geese alive.
How Do Power Line Marker Balls Work?
Power line marker balls work by providing a highly visible warning to pilots and others who may encounter power lines. These balls, typically made of lightweight materials like plastic, are painted different colors like aviation orange, white, or yellow to ensure they stand out against the sky and terrain.
Some power companies also use alternating colored balls to make it easier for pilots to distinguish between different sections of power lines. The balls are placed along the length of the power line at regular intervals. This helps indicate the power line’s presence to anyone flying or operating machinery.
By providing a simple yet effective solution to a potentially deadly problem, power line marker balls have become vital to ensuring the safety of pilots, boat operators, and other individuals who operate machinery near power lines.