As part of a transmission line rebuild by Maine Electric Power Co. between WIndsor and Orrington, steel cross-arms (foreground) are raised into place in Windsor next to older wooden structures on Route 105. The wooden structures eventually were torn down once conductors were transferred to new structures. Credit: Courtesy of Maine Electric Power

Maine Electric Power Co. has finished rebuilding an aging 51-mile transmission line ahead of schedule and under budget.

Maine Electric Power, a company that is jointly owned by Central Maine Power and Emera Maine, rebuilt the line between Orrington in Penobscot County and Windsor in Kennebec County six months ahead of schedule and $35 million under budget, the companies said in a statement released late Wednesday.

They said the early completion reduced the anticipated project costs from $105 million to $70 million.

Maine Electric Power works exclusively on transmission lines in Maine. Those lines are an essential part of the electric energy infrastructure to move bulk power through the grid to be delivered locally to businesses and residents.

Maine Electric Power owns the 182-mile transmission line that runs from Wiscasset to the New Brunswick border.

The companies said that wooden poles and cross-arms had deteriorated in two sections of the 345-kilovolt transmission line and had reached the end of their life, so they needed to be rebuilt.

Over the course of the project, 452 structures were replaced, most of them two-pole H-frame structures.

The original Maine Electric Power transmission line construction was completed in the early 1970s.

Most of the work over the 18-month construction period was done under energized conditions, or working with live wires, to minimize disruptions to the electric grid, the companies said.

In March and April, the company will perform ground tests and environmental restoration.

“Because we were working with energized lines, safety was the primary consideration of the Maine Electric Power team. They worked safely and efficiently to finish this important project ahead of schedule, and I am pleased that Maine residents across the state will benefit from more reliable power delivery,” Douglas Herling, president of Maine Electric Power and president and CEO of CMP, said in a prepared statement.