Construction of the Nucla-Sunshine 115-kilovolt, 51-mile transmission line began in the spring of 2010. It is being built around some steep forested mountains, across canyons, high alpine meadows and rugged high altitude terrain that is only accessible to construction crews and equipment between April and October, when mountain snows subside. In addition to the construction challenges brought by the weather and topography, a total of 10 miles of the line will be buried underground on Wilson and Specie mesas to satisfy local landowner concerns.
The new line replaces a more than 60-year-old, 69-kV line owned by Tri-State member San Miguel Power Association. This line is no longer adequate to serve the electrical requirements of Telluride in the event that its primary 115-kV line fails due to avalanche or other extreme weather events.
“Right now, we have about 70 people working on the project,” said Pat Dille, transmission project manager for Tri-State Generation and Transmission in the cooperatives online newsletter Powering the West.
The main contractors on the project are General Cable, whose construction crews will soon be laying the underground cable in the excavated 10-mile trench that was completed last year, and Great Southwestern Co., the primary contractor for overhead line construction.
This spring, overhead line construction is underway and crews are progressing on the segment between Norwood Substation and Beaver Mesa, according to Dille. In addition to the overhead line and underground cable, the project also involves modifications or new construction at a total of four substations along the 51-mile right-of-way.
“Modifications to the Norwood Substation are underway,” Dille said. “Construction is also progressing on the new Wilson Mesa Substation, along with ongoing modifications at Sunshine Substation. This fall, we will complete modifications at the Nucla Substation, which will be among the last phases of our construction on the line,” he added.
Dille said they are planning to begin energizing the Nucla-Sunshine line in October 2012.