“I personally call them ‘tree chunks,’ ” said Mike Hyland, senior vice president of engineering services at the American Public Power Association in Arlington.
Before we get to what tree chunks are and why they exist, it’s useful to get a crash course in what is now called the utility pole.
Of course, it started out as a telegraph pole, holding up the wires that spider-webbed across the country in the middle of the 19th century. They often followed railroad line rights of way.
Then came electric power.
“When the electric utilities were infants, they didn’t have much money,” Hyland said. They didn’t want to duplicate expensive infrastructure.
“We were begging to get on the poles.”
Electric utilities made arrangements with the telegraph — and then the telephone — companies to share space. They installed electric wires under the communications wires that were already at the tops of the poles.
“You can already understand the problem that created,” Hyland said. Servicing a telephone wire required climbing past a voltage-filled electrical wire.
“Telecommunications workers not used to working with electricity would put a ladder up against a pole and take a blanket or carpet to put over the electric lines and then stand on that carpet and work on their communications lines,” Hyland said.
Often, this did not end well.
Things could be dangerous for consumers, too, when poor line hygiene meant that electric wires and telephone wires touched where they came into a house.
“You can look at some headlines in newspapers in New York City around 1910 where someone hears the telephone ring, picks up the phone and gets electrocuted because the telephone line crossed the electric line,” Hyland said.
In 1914, industry groups and government regulators got together and came up with a set of rules, including that power lines had to go at the top of utility poles and that there be a buffer zone of at least 40 inches beneath them.
That’s still the arrangement, though the types of wires that vie for space on a pole have multiplied: telephone wire, cable wire, fiber optic wire . . .
In a wooded area, wires can rub against a tree trunk or branch, wearing down the bark. As the tree grows, it grows around the wire.
That isn’t necessarily a problem with some wires, but it is with higher-voltage electric lines. Hyland said a line carrying around 4,000 volts — 4KV in the lingo — can usually withstand trees. But most lines these days carry more than that.
“Around 34 or 35KV, a tree just breathes on that line, and electrically we’re going to have an outage,” Hyland said.
That’s why electric utilities invest so much in keeping lines clear. Pepco will spend $11 million this year to trim the vegetation along nearly 950 miles of aerial electric lines.
“We don’t have an issue with tree chunks because we’re always actively maintaining our lines,” said Tasha Jamerson, a company spokeswoman.
The tree chunks Answer Man has seen have mostly been on telecommunications lines, which Jamerson said Pepco’s crews don’t touch. They’re the responsibility of crews from those utilities.
Hyland said that in his travels around the country, he has occasionally seen lone branch bits on electric wires, too. Wherever they are, they are extra, unsightly weight that could stress the line, especially in the wind.
“I always wonder what’s going through the mind of the tree trimmer,” he said. “Is it that they’re told to trim to make [the line] clear, but also they’re not certified to work with electric utilities?”
They don’t want to get too close to the wire, and so they play it safe, cutting away on either side of the wire.
Something else may come into play: a fear of making things worse. As Hyland put it: “The last thing a tree trimmer wants to do is get in there and start cutting around and he cuts your cable, cuts your fiber optic.”
A tree chunk should eventually rot and fall off on its own accord, he said.
There’s another reason utilities strive to keep branches away from power lines: “The squirrel population can come over from the trees and get right on the line,” Hyland said.
But that’s a story for Squirrel Week.
For previous columns, visit washingtonpost.com/people/john-kelly.