Project strengthens 345kV lines stretching 1,680 miles across member communities
Upgrading 1,680 miles of the grid is a significant endeavor in the best of times. Throw in a pandemic, and it’s easy to imagine how the whole thing could get off track.
But that’s not what happened with a recent Hoosier Energy project.
“Our crews get the job done no matter what they’re thrown,” said Senior Project Manager Kyle Eslinger. “It was a great collaboration between operations, engineering, purchasing and project management overall.”
It is important to learn how they did it by looking at what took place.
Through an internal study, Hoosier Energy learned it would significantly increase grid reliability for members by upgrading the 345 kV line that stretches from Bloomington to Worthington to Sullivan.
It’s easy for bad weather or a vehicle collision to take down a pole. And once one pole falls, it can start a domino effect.
“One pole falls and it pulls on the wire and it then will pull down the next pole because of the wire,” explains Manager of Power System Design Brett Stephens. “And it pulls down the next pole and the next pole and the next pole.”
To stop the chain reaction, the G&T strategically places poles that are designed to withstand that force called dead-ends. The problem was that there weren’t quite enough of these structures on the stretch in question — and the existing structures were aging.
The project, which began in 2017 and just wrapped up this year, was designed to ensure that dead-ends are no further than five miles apart. The old dead-ends, which were all made of wood, were replaced with steel — and the engineering team made sure they were strong enough to hold steady no matter what might stress them.
“It was determined that the structures needed to be put on a concrete foundation that is some 8 feet in diameter and 30 feet in the ground to stop such failures,” Stephens said.
Some of the locations for the dead-ends did not have easy access. That caused another challenge.
Crews built access roads to each pole being replaced — and then dismantled it once the work was done. In one case, the road was a full half-mile long.
“We know the terrain, but some of the dead-ends were down in some pretty low-lying areas,” Stephens said. “So it was challenging to have to deal with water in the spring.”
The crews also had to make sure the existing poles did not have an eagle’s nest built on top – none did. To help thwart nest building and the outages needed to safely relocate nests, the new poles used are designed with domed tops.
This project was on schedule going into the last phase of the project that included replacement of six structures in Sullivan County. Work was scheduled, equipment purchased and crews were ready to finish the upgrades.
“We got done six weeks early,” said Eslinger. “That’s going to save our co-op money. Our guys will make anybody look good.”
But, at the end of the day, money is not the most important thing, according to Eslinger. It’s working together for the benefit of everyone — and keeping everyone safe.
“I don’t put those guys in a situation I wouldn’t put my son in,” he said. “It’s like a family. We’re all watching out for each other.”