Ask Ron Runion, design/build group leader at Tucson Electric Power Co. (TEP, Tucson, Arizona, U.S.), to name his top three priorities and he'll tell you, “My safety, the safety of my crew and the safety of my customers.”
Most linemen will tell you that safety is the critical component of their daily work. Ask a utility executive like Jim Pyers, TEP's vice president of operations, for his priorities and you'll hear, “The safety of our people, the integrity of our system and commitment to our customer, and the cost of the solution.”
Safety. Customer. Cost. These are the factors that the linemen and management at TEP, the electric utility owned by UniSource Energy Corp. (Tucson), considered during their search for a wood pole alternative.
TEP replaces between 1000 and 1400 of its 180,000 distribution poles annually, many of which are situated in back-lot and other limited-access areas such as easements in heavily urbanized settings.
“We were looking for a solution to our limited-access distribution pole needs based on safety, cost and ease of use,” says Pyers. “What we found was a new fiberglass pole design that met our requirements for many of our distribution pole applications.”
TEP chose hollow pultruded fiberglass reinforced composite (PFRC) poles, manufactured by Powertrusion International Inc. (Scottsdale, Arizona), for much of its new construction and replacement distribution pole needs. Apart from a small number of concrete poles, wood had been the dominant player in TEP's distribution pole strategy. After two years of evaluating concrete, steel and “old technology” fiberglass poles, TEP determined the new PFRC design was superior in cost, function, weight and safety. This decision represents a change in tradition for TEP, as it would for most U.S. electric utilities that have used wood for more than 90% of their distribution needs for more than 100 years. Yet the comprehensive study of safety factors, cost-benefit analysis, environmental impact and ease of use related to wood, steel and PFRC alternatives supports this move.
“PFRC poles cost more than wood poles up front, no question about it,” Pyers explains. “But when we evaluated the whole picture, from point of manufacture through delivery, stocking, installation, inherent safety, maintenance, useful life expectancy, disposal and environmental risk, PFRC poles proved not only the safest and easiest to work with, but also more cost effective.”
In balancing the merits of PFRC poles, TEP considered several factors compared to alternative products.
According to Rich Gonzales, senior standards engineer for TEP, the company initially had reservations about changing to PFRC poles because of disappointing experiences with earlier fiberglass pole types.
“Some composite poles are manufactured using a filament-winding process that spins glass filaments around a core for the full length of the pole. Powertrusion's process arranges the fibers vertically as well as horizontally,” Gonzales says. “That provides both lateral and longitudinal strength. This ‘new’ composite design results in a lighter, more cost-effective pole that we found more aesthetically pleasing.”
Gonzales further notes the advantages of the lightweight PFRC poles. In the event the poles are broken by wind or vehicular impact, the conductor often ends up supporting the weight of the pole.
“The difference with PFRC is that the pole weight is only 370 lb (168 kg) rather than 1000 lb (454 kg) or so for wood. The lighter weight offers a much greater chance for the conductor and adjacent poles to support the weight of the broken pole without being dragged down themselves,” he says. The “domino effect” of one falling pole taking down several more poles is a costly occurrence.
TEP installed Powertrusion's poles in space-restricted areas to determine if the requirements for these installations were significantly different than for wood poles. Runion directed a line crew changeout of an older wood pole and transformer in a brush-choked easement in a Tucson residential area.
“Four men easily carried the PFRC pole for 50 yards (46 m) in tight quarters where they had to maneuver in and out among trees and cactus,” comments Runion. “If we had been replacing wood with wood, 10 or 12 men would have been required to carry the extra weight, and they would have had more trouble navigating through the obstacles. We save at least eight man-hours and the cost of three or four additional truck rolls when we use PFRC poles instead of wood.”
Pyers estimates TEP will consistently achieve a carry-and-set man-hour savings of about 40% when using PFRC poles in limited-access installations. Crews that aren't needed to handle the extra weight of wood poles become available to deal with other maintenance and trouble tasks. TEP also anticipates savings from changes to other traditional processes made possible by the lighter pole.
David Crobbe, director of materials operations at TEP, sees considerable savings potential from the receipting, inspecting and warehousing of poles.
“We've eliminated the costly manual inspection of individual wood poles that linemen require as a safety measure,” Crobbe says. “The engineered and non-tapered nature of these fiberglass poles allow us to visually inspect and stock poles in one-tenth the time required for wood poles, and it requires less-expensive equipment. This translates to around US$1000 in material operations savings alone for each 50 poles delivered.”
TEP also contemplates reduced equipment costs for hauling and setting the lighter poles as well as reductions in hardware parts because of the non-tapered pole. Realized and potential operating savings were strong considerations in TEP's purchase decision.
More important, though, is the human confidence and safety factor. “The lineman's priority is safety,” Runion emphasizes. “My priorities are my safety and the safety of my crew. No amount of time or money savings outweighs the need to work safely, and that's one reason why linemen are comfortable working with these PFRC poles. They're easier to handle than heavier wood poles, so the chance of weight-related injuries is reduced, and their nonconductive characteristic reduces the potential danger when working with steel poles around energized equipment.
“While steel has some of the same weight advantages as fiberglass, we felt that the increased potential for safety problems and the additional costs for insulated platforms and equipment required to deal with the conductivity of steel poles was too much of a tradeoff,” says Runion.
Last year, J.D. Power & Associates conducted a survey in which TEP ranked No. 1 in customer service among western U.S. utilities. Pyers says the ranking reflects another top priority, the utility customer.
“This distribution pole decision supports a commitment to our customers for a highly reliable and environmentally sound product,” Runion says. “Alternatives that require us to de-energize our lines or continue the pervasive use of potentially harmful chemicals erode this commitment. Our industry is beginning to realize the high level of risk assumed through the continued contamination of our communities that results from wood pole use.”
Equally important to the customer and to TEP is a commitment to price. “Reducing or eliminating operating costs for setting and maintaining poles as well as mitigating ‘strategic’ environmental and disposal issues is key to meeting these objectives,” states Pyers.
TEP has been buying Powertrusion's PFRC poles in 30-, 35- and 40-ft (9-, 11- and 12-m) lengths, all rated Class 4 or higher, and plans to purchase its Class 3, 45-ft (14-m) poles as well as fiberglass crossarms this year.
One of the challenges to the composite pole industry is that industry-wide strength standards have yet to be established for composite poles. As a result, PFRC poles are inherently over-engineered to meet the more stringent wood-equivalent overload factor of 4.0, providing an even greater safety margin. Powertrusion and users like TEP are confident the PFRC poles should bear the more lenient 2.5 overload factor required for steel and prestressed concrete. In fact, Powertrusion and the composites industry are working to obtain that classification in the National Electrical Safety Code.
Breaking the wood tradition was easy for TEP once it found the lower-cost pultruded fiberglass product, particularly for limited-access applications. After considering the total cost of wood and steel poles, as measured in dollars, safety, customer satisfaction, and environmental responsibility, TEP found each of these factors supported its acceptance of PFRC as a replacement for wood in its distribution pole strategy.
Paul Coleman has served as director of business planning at UniSource Energy Corp. for the past six years. Prior to this, Coleman was a financial planning manager at IBM for 15 years.