Crews have erected about 75 percent of the 411 steel towers needed for a $175 million, 84-mile high-voltage power line between Grand Coulee Dam and the Bell Substation, near Mead, and the project will become much more visible to Spokane-area residents soon.


The steel-lattice towers, which mostly range from 125 feet to 150 feet tall, with a few higher than that and one at 250 feet, will start to go up from Riverside State Park to the Bell Substation before long, says Mark Korsness, a senior project manager for the Bonneville Power Administration, which is building the line.


Things are going well, Korsness says. Were essentially done with the foundations of most of the towers.


Crews also have strung power line on the first of the towers, from Grand Coulee to a point about 30 miles from the huge Columbia River dam, as they build the big, 500-kilovolt line in a corridor that runs between the dam and the Bell Substation, Korsness says. The line, an upgrade of a smaller line, will be one of five lines that run through the corridor. When the project is done, those lines will carry enough electricity to serve 500,000 homes, up by 25 percent.


The wires are being strung for the new line in a three-step process, Korsness says. In the first step, a helicopter carries a three- to four-mile length of lightweight fabric rope aloft and strings the rope between 15 to 20 towers via pulley systems attached temporarily to the towers. The end of the fabric rope then is connected to the end of a heavier and stronger wire rope, which is pulled between the towers by machine. In the third step, the wire rope is attached to the end of the power line, or conductor, which is heavier yet, and it then is pulled between the towers, again by machine.


The conductor, a bundle of aluminum wires around a steel wire that gives the line strength, is about an inch and a quarter across and weighs a little more than a pound per foot, Korsness says. Its often strung in the same two-mile lengths as the fabric rope and wire rope, and a two-mile length of it weighs more than five tons. The 500-kv line will have three sets of three conductors, or nine lines in all.


Henkels & McCoy Inc., of Blue Bell, Pa., is the prime contractor on the project, and Korsness says that 135 workers, mostly hired from Spokane, are on the job.


Five Spokane-area subcontractors are working on the project, with Burton Construction Inc. handling dust abatement under a $500,000 contract and four other companies here doing such things as soil and concrete testing, flagging, and weed control under contracts that range in value from $10,000 to $75,000.


In the project, BPA is upgrading one of two 115-kv power lines in the power-line corridor. Three 230-kv lines also run through that corridor. The BPA says it elected to replace one of the 115-kv lines to enhance its ability to deliver power where its needed in the region, to relieve congestion on the transmission-line corridor, to maintain system reliability, and to hold down costs.


The 80-foot-tall, closely spaced wooden towers that carried the 115-kv line thats being replaced werent strong enough to support the 500-kv line, Korsness says. The new steel towers will be strong enough to support the line and will be spaced optimally to build the line as cost effectively as possible, he says.


In the $175 million project, $85 million is being spent on construction of the line. Some $12 million is being spent on an upgrade of the Bell Substation thats being performed by Tice Electric Co., of Portland. The BPA is doing some work itself at the Grand Coulee switchyard to accommodate the new line. Other costs of the project have included design of the power line and the expense of the public-involvement and environmental-approval processes, Korsness says.


Construction of the power line began in April 2003, and is to be completed in December, Korsness says.