Crossville Chronicle, Crossville, TN

May 30, 2013

Behind the scenes of the Tansi powerline project

By Jim Bridges
Signals contributor

CROSSVILLE — There is no way you can live in Lake Tansi Village and not be aware of the power line work that has been and is being done along Dunbar Road. The first hint I had that a big job was imminent was when I saw a large pile of power poles at the intersection of Dunbar Road and Lantana Road. Next, several “line” trucks were parked near the poles and also a couple or three were parked near the sub-station across the intersection. They were white but did not have VEC logos so I assumed they belonged to a contractor who would begin work shortly.

Soon trucks began delivering poles along Dunbar Road, between the sub-station and Tansi. The company in charge of setting the poles is Galloway Construction, line construction and tree service, out of Sunbright, Tenn.

When I arrived, they were “framing” the poles. Part of framing the pole involves attaching a “cross arm.” It is bolted onto the pole using a pre-drilled hole and a “V-shaped brace” to help support it. A “ground wire” is attached as the last operation before the auger truck lifts the pole into position and lowers it into the hole. As I watched, two crew members used “plum bobs” from different directions to ascertain that the pole was straight before dirt was put around the pole and “tamped” to hold the pole in position. (As an item of interest, the  “plumb bob” goes back to the Egyptian period. For something so simple it couldn’t be more effective.)

According to Volunteer Electric Corporation Area Manager Bobby Randolph, the Crossville Service Center has 32,000 customers and is the largest office in the VEC system. The potential for growth is high in the Tansi area. The Lantana sub-station serves over 7,000 customers and has not been upgraded since it was built. Three “circuits” are fed out of this “sub” – one on Dunbar Road to Tansi; a second one on Lantana Road, down Taylor Chapel Road and into Bledsoe County; and a third one on Lantana Road towards the city limits of Crossville. The circuit that feeds down Taylor Chapel Road and into Bledsoe County serve 2,200 customers, and is the longest circuit in the VEC system.

Bobby said VEC engineers recognized the potential for growth in the area served by the Lantana sub and decided to do an “upgrade” before the need arrived. Emphasis was placed in four areas: Upgrading the sub-station, changing out the two main transformers, adding two breakers and adding two new circuits. Here is the background on these areas.

The two transformers that were installed when the sub-station was built were 20 megawatts each giving a total output of 40 megawatts. The two new transformers that have been installed are 50 megawatts each giving a total output of 100 megawatts, doubling the station capacity.

Galloway Construction is setting new poles and line crews using “bucket trucks” are transferring the existing power service wires to the cross arms at the top of the new poles. By using insulated covers on the wires being transferred, the line crews are “working” the lines “hot.” This is the reason the power has stayed on all the time they are working.

The upgrades will double the capacity of the Tansi area, as well as the service down Taylor Chapel Rd, and will give better reliability for the “winter” (heat) load. The parallel three-phase service to Tansi is known as “double circuiting.” The last pole to be replaced in Tansi will be near the causeway on Dunbar Road.

When driving on Dunbar Road, you will notice that once the power lines have been transferred from the old to the new poles, the tops of the old poles are cut off. The wires left on the old poles are telephone and cable lines. Phone and cable companies pay attachment fees to VEC for the privilege using their poles. VEC notifies these companies when power lines are removed and from the date of notice, they have 30 days to remove their lines. After that, ownership and liability become theirs. If the phone and cable lines are removed within 30 days, VEC will remove the cut-off poles.