Entergy Arkansas and Aerial Solutions Inc. demonstrated use of the Aerial Saw, which utility officials say is a big improvement over traditional methods of trimming trees along major transmission-line pathways.
Aerial Solutions general manager Ted McAllister says the rig dangling from a helicopter can do in an hour the work that would take crews on the ground two or three days to perform. The assembly of ten 24-inch blades piled vertically at the end of a 90-foot boom under the helicopter is used to trim branches that grow toward transmission lines from nearby trees.
Entergy spokesman James Thompson said keeping those branches cut back is an important way to help keep electricity flowing even during the worst ice storm — and of keeping forest fires away from the transmission lines that flames could destroy.
"When fires start getting into these big 500-kilovolt lines, a shutdown affects thousands of customers, not just hundreds," Thompson said.
Aerial Services, based at Tabor City, N.C., has six Aerial Saw helicopters and crews that work to keep transmission-line pathways clear for utilities around the country, McAllister said. The company has a contract with Entergy and the crew now in Arkansas worked earlier in Mississippi and will eventually head to Louisiana, covering all three states in the main Entergy network.
The other five crews, he said, are currently working for utilities in Illinois, West Virginia, Kentucky, Ohio and South Carolina.
The company's work isn't cheap. McAllister said utilities are charged $1,800 to $1,900 per hour, but trimming the trees much more quickly means the electric companies can actually save money when compared with having their crews do the work over several days' time.
And it's safer, he said. "They don't have their crews out their using chain saws," McAllister said, with all the potential for serious-injury accidents.
Normally, an Aerial Saw crew will consist of just two people — a pilot at the controls of the helicopter, who does the actual branch-trimming, plus a ground crewman who maintains the saws and keeps them operating efficiently.