Soon 22 miles of transmission line will cross over mountains, pass casinos and cut through a gold mine in Colorado. Black Hills Energy (Pueblo, Colorado) and PAR Electrical Construction (Kansas City, Missouri) are building a new 115-kV line to supply the mining towns of Victor and Cripple Creek, Colorado.

Linemen reconductored a 69-kV line in 1996, but as the area has developed, the line has reached its capacity. The utility opted to build a new 115-kV line parallel to the existing line that will feed a 115-kV to 69-kV substation. That way, the utility can provide temporary power to the residents during the project and then supply backup electricity in emergency situations.

By building the new line, the utility is increasing both the voltage and conductor size to handle the increased load. As of February, the utility is 15 miles into the project and has 10 linemen working on the job along with operators and groundmen. The utility started the project in June 2008 and plans to complete it in November 2009.

Reaching Remote Areas

Black Hills Energy and PAR crews are building the line through rocky, mountainous terrain with extreme fluctuations in elevations. For example, a 12-mile stretch of the line is virtually inaccessible to the line crews. The elevation also increases from 5000 ft to 9400 ft, which makes it impossible for linemen to access the area with regular bucket trucks and line equipment.

To reach the remote areas, the companies are leasing all-terrain vehicles (ATVs). While ATVs are not commonly used on high-line jobs, they are a valuable piece of equipment on this project. The linemen often have to cross steep grades, so by using the ATVs, they are able to reach any part of the line.

To keep the workers safe on the project, the utility hired an ATV trainer to teach a six-hour course. Each worker on the project is trained to operate an ATV in order to reach remote locations on the line.

Environmental Concerns

Crossing the terrain is problematic because of the extreme weather conditions. At an elevation of 9,000 or 10,000 ft, it is not uncommon to get a foot of snow. As a result, weather has played a major role in how the utility is handling day-to-day operations.

Black Hills Energy planned to work in the higher elevations in the summertime and then work down below during the winter months. However, environmental issues forced the utility to adjust its schedule.

An endangered Mexican spotted owl was discovered in the area. As a result, the utility could not be within a half mile of the owl with any heavy equipment between April 1 and Sept. 15. In the same general vicinity, the utility crews discovered a pair of bald eagles that nested along the utility's easement. The line crews could not disturb these eagles until they abandoned their nest and left the area.

Through careful planning, the utility revised its schedule and was able to continue working without disturbing the protected wildlife. Avoiding the endangered birds, however, was not the only environmental challenge that confronted the utility. The company was also restricted from building a road into the job site or making any large cuts in the road or the side of the mountain.

The linemen could not drive their trucks and equipment across the streams. If they had to cross a creek bed, they had to lay down steel plates or culverts or build temporary bridges. Erosion has been a big concern on the project, as well. After the utility has completed building the line, the linemen must take measures to prevent erosion and storm-water runoff in the area.

Up in the Air

In addition to environmental concerns, the utility also faced a challenge when it came to setting poles on the top of the mountains. To set the poles on these high elevations, the utility employed the use of cranes and three different sizes of helicopters.

Before the helicopter pilots even fly into the area, the linemen often spend about 45 days preparing the structures to be lifted into place. The linemen use both an air compressor and a 60-lb jack hammer to dig holes in the solid granite in the mountains. The linemen hook the compressor on to a Caterpillar, and then drive down a two-track road.

The work is labor intensive, and linemen are only able to dig about 2 or 3 inches at a time. Some of the holes are 15 ft deep, and it often takes the line crews five days to dig one hole using a three-person crew.

After drilling the holes, the linemen tamp the culverts in and frame the poles in the yard. The line crew also attaches cable chokers to the poles, so the helicopter pilot can lift the load from the yard and fly it to the desired location.

On the “fly date,” the utility gives the helicopter pilots a specific instruction sheet describing the exact location and rotation of the poles. The helicopter pilots then pick up framed poles, hover above the site and then work with the foreman on the ground below to guide the pole into position. One foreman is assigned to each structure, and on a fly date, he or she wears an orange safety vest and communicates with the helicopter pilot using a handheld radio and hand signals. On average, the helicopter can make a pick in about six to eight minutes, and a pilot can fly about 40 structures in four to five hours.

Linemen can face many safety issues on a fly date. To protect the line crew, the pilot organizes a tailboard meeting to discuss where linemen should and should not stand near a helicopter. They are also advised to tie everything down, including personal protective equipment, so nothing gets blown away by the backwash from the helicopter. Oftentimes, the backwash that comes off of the helicopter blades blows at 50 mph, which can whip materials around on the ground below. The gust of wind can push a lineman 10 ft away from where he or she is standing. In addition, linemen have to be careful due to the extreme amount of heavy weight above them during a pick.