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September 19, 2020

Electric Line Requisites


During informal discussion following their special meeting on August 14, Hinsdale Commissioners Whinnery, Dozier and Thompson discussed the somewhat daunting logistics of installing an electric line in conduit from near the old Golconda Resort at Lake San Cristobal seven miles up Slumgullion Pass to the Hill 71 communications site.
As enumerated at the meeting, in addition to seven miles of conduit into which electric cable will be threaded, the $625,000 project now also entails 3,100’ of empty 1’1/2” diameter fiber conduit for the eventual installation of broadband cable which will be co-installed with the electric conduit along the right-of-way and beneath Highway 149.
Gunnison County Electric will be the contractor on the project, although Hinsdale County Road & Bridge staff and equipment are requisites in terms of providing in-kind work and overall cost savings to the county.
As an example of the logistics, Hinsdale Road & Bridge will be responsible for transporting and positioning the weighty rolls of conduit and cable. Each reel contains approximately 2,300’ feet of cable — one separate roll for the orange-colored conduit and a second reel with the aluminum electric cable.
Reels will be delivered at incrimental locations along the seven-mile route, particularly daunting on steep sections of Sawmill Park leading up to Hill 71.
It is a virtual given that the dirt-surface, 4-wheel drive Sawmill Park Road will temporarily be obliterated as a result of the excavation work.
The process to be followed in the conduit and cable installation is roughly thus: the county’s in-kind work for the project involves a D-8 dozer which will be equipped with a four-barrel, 4’-long “ripper.” This ripper will preceed the installation by literally ripping up the ground to a 4’ depth.
While the subground surface of the Highway 149 right-of-way is fairly predictable, the subsurface of the Sawmill Park Road is anything but a given. Added time and expense may occur as the ripper encounters solid rock strata or immense boulders which will necessarily be pulled up and out of the roadbed.
After the county-supplied D-8 dozer rips up the ground, next in sequence is Gunnison County Electric’s cable plow. The reel with orange conduit is mounted onto the plow and, furrow-like, lays the conduit at a precise depth.
Once the conduit is in place, the next step is an air compressor mounted on a trailer. Compressed air is used to literally blast a small ball through the empty condit. Attached to the ball is a nylon cord which, once it exits the opposite end of the conduit, is secured to one end of the aluminum electric line and fed back through the conduit using a winch.
The interior of the 2” conduit is slightly lubricated to aid in installing the electric cable.
Reels, as stated, carry about 2,300’ of cable and wire. At the completion of each reel, a t-connection occurs in which the end of the conduit passes through a pedestal known as a “pull box.” At each junction box the separate lengths of cable are connected.
As a separate complication already envisioned by the county, the Sawmill Park road surface will need to returned to driveable condition. Erosion on the rebuilt road surface is a concern since runoff will naturally seek a course directly down the road. For this reason, horizontal water bars will be installed periodically to redirect water from scouring the center of the roadway.

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