County, Gunnison Co. Electric Finish 7.78-Mile Installation to Mtn. 71
Hinsdale County and its installation partner, Gunnison County Electric Assoc., apparently lucked out in terms of adverse weather as the duo completed installation of its 7.78-mile electric line in a record 30 days.
The county’s new single-phase electric cable in conduit is buried at a depth ranging from 38” to 42” extending from the Mountain 71 communications site at a brisk 12,294’ elevation down valley beneath and adjacent to Highway 149 on Slumgullion Pass before ending on the toe of the Slumgullion Slide on the east side of the Lake Fork River.
Ending for the seven-plus-mile electric conduit occurs with existing power at the new east extension of the Campbell family’s Highlander RV Park.
The old portion of the RV park is located adjacent to County Road 30 on the west side of the Lake Fork River, although the park has now been expanded to the east side of the river on Slumgullion Slide where electric power has been extended.
Completion of the electric line conduit, together with a 3,300’-section of “ghost” conduit on Slumgullion Pass which will be used for the installation of fiber optic cable at a later date, eliminates the need for solar power at the 71 Mountain communications site.
Total cost of the project will be approximately $529,000, $375,000 of which was awarded to the county by Colorado Dept. of Local Affairs. Hinsdale County contributed a $75,000 cash match and provided $79,000 of in-kind labor.
Providing power to the emergency communication site has become increasingly vexing with the uncertainties of solar power in recent years; equally
exasperating to the county and road crew personnel
the past several winters has been the need to buck snow drifts as they delivered diesel to run a backup generator at the communications site.
With underground power now assured, and final tie-ins now being completed by GCEA, single-phase electric power to the mountaintop site may be up and running by as early as next week, according to GCEA CEO Roger Grogg.
Work installing the electric conduit and cable began at 1:30 p.m. on Tuesday, September 4, Hinsdale County’s portion of the excavation work officially completed as of Monday, October 1.
As of last week, according to Grogg, final tie-in work was completing as GCEA staff worked to connect the electric cable in a total of 26 above-ground junction boxes which extend from 71 Mountain down onto the Slumgullion Slide. Much of the route from the 71 Mountain communication site down to Highway 149 on Slumgullion Pass followed the route of the Sawmill Park road through Sawmill and Rambouillet Parks. Hinsdale Road & Bridge Supervisor Monte Hannah tells SILVER WORLD that the excavated road is now reopened to 4-wheel drive traffic, complete with periodic water bars to keep the road from eroding, although further cleanup and smoothing is scheduled late next spring.
Start of excavation work in early September followed a delayed contract-signing between Hinsdale County and Gunnison County Electric in which the county agreed to pay GCEA $398,255. Although the project did, in fact, span just a month, the contract allowed up to six months for completion. For its portion of the project, Hinsdale County Road & Bridge temporarily augmented its fleet of excavation equipment with a mammoth 90,000-lb D8-T dozer which was rented from Wagner Equipment Co. in Grand Junction for $17,835 for one-month’s use. Attached to the dozer was a 4’-long ripper which broke up the ground along the cable installation route.
Following the D8-T dozer was Gunnison County Electric equipment consisting of a dozer onto which 3,000-lb reels of 2,500’ cable were mounted. The dozer is also equipped with a vibrating “plow tooth” through which the cable is ingeniously threaded. The vibrating tooth installs the conduit with electric cable into the loosened soil at a uniform depth of 38” to 42”. At the end of each reel at 2,500’, a new reel of conduit and cable was loaded and a junction box installed to connect the lengths of cable.
In addition to the 7.78 miles of conduit and electric cable, and per recommendations for Citizens for Hinsdale County Broadband, 3,300’ of empty conduit and five junction boxes were also installed along a section of Highway 149 from the start of the Sawmill Park road and extending roadside to a point where the conduit branches off down the Slumgullion Slide. Cost for empty fiber conduit and installation borne by Hinsdale County is estimated at $5,800.
Installation of the conduit was complicated by two subsurface highway crossings and steep terrain.
Two bores were planned beneath the highway, one at lower elevation extending 60-70’ in length under the asphalt, and a second, more demanding, bore which was planned to extend approximately 475’. The uphill bore was planned just below the Lake San Cristobal overlook hairpin curve on Highway 149 and extend at a sharp angle uphill to re-emerge at the start of the Sawmill Park road.
Extreme length of the bore and variable subsurface
rock formations made the excavation impossible, however. The boring contractor, Apeiron from Grand Junction, made six attempts at the 475’ bore and repeatedly broke drill bits before finally giving up. As an alternative, Apeiron successfully completed a 60’-70’ bore beneath Highway 149 at the entrance to the Sawmill Park road through which a 4”-diameter conduit sleeve was installed containing 2”-diameter electric conduit and 1-1/4” empty conduit for eventual fiber.
After emerging from beneath Highway 149 on the opposite side of Highway 149 from Sawmill Park road entrance, the electric conduit and ghost fiber conduit makes a precipitous drop on the ground surface through the aspen and conifer forest before re-emerging above Highway 149 475’ down the slope. The majority of the conduit, approximately 450’ in length, will remain on the ground surface through this stretch, with the final 50’ buried as it descends a visible embankment immediately above the road.