You can’t miss them when you look up – the bright red, orange, white or yellow spheres hanging from the power lines overhead. And you’ll notice that they’re spaced perfectly apart, too. It all seems they have a purpose, but you’re not quite sure what it is – yet.
When these spheres started appearing is a fact that’s up for debate. Some say that the red balls began popping up in Florida and Arkansas in the 1950s. Others argue it happened two decades later in the latter state only. Whatever the case may be, you will see them across the country nowadays.
From below, the balls hanging from the power lines overhead might not seem that big. But remember that some are hundreds of feet in the air, so what you see on the ground isn’t their true size. In fact, the larger spheres measure in at least 36 inches, according to Mental Floss.
And the publication notes that balls which hang a bit closer to the ground – say, about 50 feet above where you stand – are only 20 inches in size. They are spaced a bit less generously than their more sizable counterparts, though. Smaller spheres can be a mere 30 feet apart, while the bigger ones are separated by about 200 feet.
Clearly, this is all part of a well-regulated system. So, what purpose do these brightly colored, perfectly sized and evenly spaced balls have to say to passersby? If you don’t yet know, there’s a good chance that you’re not in the industry – and it’s not the one you think.
It took until 1882 for engineers – specifically German Oskar von Miller and Frenchman Marcel Deprez – to send electricity over a long distance. The pair relied on overhead wires that would normally transmit telegraphs. With that cable, though, the pair sent an electric current of 2.5 kilowatts over a 57-kilometer stretch.
Before then, though, a power plant could only serve its local area. That meant electricity had a short journey from its point of creation into the businesses and residences that needed it. Nowadays, utilities companies have moved into larger, more remote facilities. And that means they have to send electricity to customers in new ways.
To fix this problem, power companies had to come up with a way to efficiently transport electricity from its point of creation all the way to customers. This was no easy task, and any wasted power was money lost for these businesses. So, they had to come up with the right conduction system to send electricity across lines.
The metal power lines you see running overhead send high-voltage electricity from plants and into the areas where people live and work. The lines aren’t insulated, which experts have deemed an unnecessary and costly feature when the lines run so far above ground. Any underground lines will be insulated, though, to protect people walking or working in the area.
But what are the most common accidents when it comes to power lines? Well, it turns out that most of them are work-related electrocutions. They occur when a worker or their equipment touches the cable while also touching the ground. This creates a sort of conductor – allowing the power to travel from the live wire through the person and into the earth.
That explains why birds can sit on power lines without any problems. Electricity won’t stray from the lines unless it has a pathway into the ground. So, the winged creatures can sit on the wire without feeling the deadly surge. Though they do have problems if they touch two wires at once, or if they simultaneously touch the line and the wooden poles that hold them up.
Power companies have done their part to make sure that birds don’t find themselves in either one of these scenarios, though. Namely, they have increased the amount of space between the lines so that they can’t touch two wires at once when they sit down. Otherwise, they’re safe to take a seat on the power lines, as you’ve certainly seen them do.
It’s not just birds we see on power lines, either. Sometimes – especially in cities – you might catch sight of shoes hanging up there, too. People tie a pair of laces together, then launch them up toward the power lines. A good throw will hook the shoe over the wire – but why would someone do this?
Between 2008 and 2015, the city of Chicago received requests to remove a whopping 6,000 pairs of shoes from power lines there, according to the radio station WBEZ. It’s not an issue exclusive to the Windy City, either. You’ll see sneakers dangling overhead in places across the globe, and it’s a phenomenon with many possible explanations.
Some have linked sneakers on power lines to urban violence – especially clashes related to gangs. A former member named Patrick Starr confirmed this to WBEZ in 2015. Apparently, he and his crew would mark their territory with overhead footwear. In other cities, gangs used shoes to signal where rivals had died or where their own had fallen victim to violence.
There are other theories about hanging shoes – including the idea that they represent a spot where people sell drugs. Chicago locals refuted this notion, though. And then, there were stories of people whose friends had pranked them or tossed their sneakers as payback for a lost bet. So as we can see, there’s no single reason why shoes end up overhead.
Of course, sneakers aren’t accessories added to electrical cables by city or state officials. There are a few baubles that they might hang on the power lines, though. Unlike dangling tennis shoes, such state-approved accents have a clear purpose and meaning for those who know how to interpret them.
Perhaps you’re looking at a transformer and the high-voltage lines that jut from it. You might see what looks like discs or another circular shape around the electric cables. Regardless of the color, these shapes are probably insulators to prevent the live wires from touching anything that could cause a shock.
Specifically, if the wires run next to or into a transformer, they have a direct pathway to the ground. And, because most transformers are metal, this can conduct electricity into the ground, which power companies don’t want. So, they put insulators around the cables to separate the wires from the transformer’s edge
Insulator disks can also protect power plant transformers from storms and electrical surges. Namely, if the power lines get struck by lightning – and they touch the transformer – a blast of power could run into and damage the machinery. Insulators prevent this from happening, as well.
Perhaps you’re nowhere near a transformer, though. And what you’re seeing isn’t a disk-shaped stack on a power line. No, what you’ve noticed is unmistakably spherical – a giant plastic ball hanging from the electrical wires overhead. You might be floating across a lake, driving through a canyon or simply passing by your local airport.
These balls apparently come in a variety of colors. At first, the go-to hue was red, but experts transitioned to using bright orange later on as their default. Still, you might still see a crimson sphere – alongside the more standard fiery hue, yellow or even white. They come in different sizes, too. According to Mental Floss, they tend to be 36 inches in more remote locales and 20 inches closer to the airport.
The balls generally sit at 200-feet intervals from one another, although they might be closer together when you get closer to an airport. All of these details give a hint as to the purpose of these spherical additions to your local power lines. And there’s one last ironic detail about them to consider.
Interestingly enough, the giant power line spheres you see have to be attached to the wires in a death-defying manner. Workers can’t always climb up and reach these extra-high lines, to which you see the balls attached. So how do teams get up there? Well, they sometimes have to fly in a helicopter, which hovers next to the cable for long enough to attach the massive, brightly colored bead.
As we mentioned earlier, some say that these markers started appearing in the 1950s. Apparently, that decade some states including Florida and Arkansas began to hang them on their electrical wires. Though others say the trend started 20 years later in Arkansas, when the state’s governor took a flight and subsequently noticed something disconcerting upon landing.
Supposedly, Arkansas’ then-governor Winthrop Rockefeller looked out of the window of his plane and saw electrical cables flying by him on landing. He thought the live wires should be made more obvious to pilots making their way toward the runway. So, the spheres started appearing as a warning to aviation professionals – steer clear of the dangerous cables ahead.
Pilots in other states didn’t have the same warning system – at least, not as early as they had them in Arkansas. In the late 1980s Colorado officials began to install them across their state’s famously rugged terrain. But they didn’t do it quickly enough to prevent a tragedy over the South Platte River.
In 1988 a news channel’s helicopter collided with a thin steel cable that dangled 150 feet over the South Platte River. And a collision with that wire was enough to cause the vessel to crash. On board were two journalists, who were both sadly killed in the disaster.
Even with that and other crashes logged, though, the Federal Aviation Administration (FAA) can’t make it a requirement for every state to hang the colorful balls on their live wires. Instead, they can only recommend that they use the warning symbols to protect overhead aircraft from a fatal collision.
You might be surprised to learn that it’s not uncommon for helicopter pilots to collide with live wires. A 2003 report in FAAviation News explained that they often miss the cables due to a number of issues. These include “dirty windscreens, light conditions, the obscuring effects of terrain and changes in visual perspective that occur during climb and descent.”
On top of that, the report stated that “accurately judging the helicopter’s distance from unmarked wires is nearly impossible.” Even a pilot who follows the same path back and forth from the airport could be at risk when wires tighten in changing temperatures, the color of the cables change over time, or if another optical illusion presents itself.
There are also certain places where you’re more likely to see these spheres – known as visibility marker balls in the aviation field. They tend to dangle in spots where planes and helicopters tend to fly low, such as canyons, mountain passes and valleys, as well as over freeways and leading into the airport.
The cables that zigzag across these aforementioned areas have to be tagged with the visibility marker balls. Otherwise, as planes start to descend, their pilots might not be able to see the cable ahead. The FAA guidelines stipulate why the balls should come in certain sizes and colors, too.
As previously mentioned, the spheres you see over lakes, rivers and canyons are extra-large – the FAA stipulates that they be at least 36 inches across. Meanwhile, smaller markers – 20-inch balls – are enough for power lines that are 50 feet in height or less. You’ll see the sized-down version at the end of airport runways, as well.
The larger balls – hung from the more remote, regular-height wires – can be spaced 200 feet apart. If you look out of your airplane window, though, you’ll see the spheres are much closer together as you taxi toward the end of the runway. Those markers tend to have 30 to 50 feet between them – highlighting the edge of the tarmac.
In the middle of the 20th century, the first visibility markers came in a bright red hue. Though a later FAA study found that orange was a more visible shade for pilots. So, you’re more likely to see the fire-colored spheres hanging from power lines nowadays, although there will still be exceptions.
Ultimately, it’s down to the surroundings in which the markers will hang. The color that makes them the most visible to pilots is the paint color that local officials should choose. Yet in most cases that hue is “aviation orange,” according to Mental Floss.
If a wire houses less than four markers, then all four of them should come in this eye-catching shade of clementine. Yet longer wires with more markers might be better served with a pattern of colors. Most alternate between orange, white and yellow to ensure that one of the colors catches the pilot’s eye.
As time has gone on, more benefits of the visibility markers have been noted. For instance, in 1983 an article from United Press International pointed out that the cable markers helped steer geese away from dangerous live wires. Boat captains had learned to avoid them, too, the piece noted.
That’s great news for professionals across aviation and boating industries, as well as those concerned with wildlife conservation. The giant, colorful spheres on your power lines do something – they save lives. And, now, when you drive by and see them in their orange, red, yellow or white hues, you can appreciate all they do just by dangling from your city’s electrical cables.