DOWNLOAD PDF By Kevin C. Coates Utilities have been working with several composite pole manufacturers and deploying various types of composite poles to service locations as pilot projects to evaluate composite pole performance. Recent winter storms have shown that composite utility poles have some important advantages over wood, concrete and steel structures. The storms that blasted across Canada and the northern tier of the United States this past winter often left behind a beautiful blanket of snow and ice. Only with some of these storms, the peace and tranquility that normally accompanies the end of a gentle snow fall was instead punctuated by loud periodic “cracks” and “booms;” the sounds of wood poles snapping like toothpicks, felled by trees that collapsed under the weight of massive amounts of ice and snow. Environmental regulations now consider treated wood poles as hazardous waste. In several instances, composite utility poles were installed as pilot projects in amongst the old wood pole infrastructure. To the amazement and pleasure of the host utilities, none of the composite utility poles came down or were significantly damaged. The various composite pole manufacturers could not have asked for a better test to prove the durability of their innovative poles. What is now becoming increasingly obvious to the electric power industry is that some composite utility poles have finally matured into the “ready for deployment stage” where they can now be accepted as part of a utility’s replacement pole inventory. And, small wonder considering the potential cost savings that composite poles represent for utility pole installation, maintenance, repair, replacement, life cycles, and disposal. The effects of weathering, termites, woodpeckers, rusting, high winds, and fires take a toll on pole infrastructure every year, which of course drives up maintenance costs, and reduces overall system reliability. The new generation of composite poles effectively mitigate these negative effects. Significant advancements have been made in the design and manufacture of transmission and distribution poles using new high-strength E-Glass fibres and polyurethane resins. Utilities are beginning to recognize that composite poles manufactured with these new materials hold promise for dramatically reducing pole life cycle maintenance and the need for frequent pole replacements, even for reasons other than age. These improvements also hold promise to reduce the initial cost of setting a pole as well as reducing the need for pole replacements. Background The first poles used to support telegraph lines in the 19th century were from old growth or ancient forests and typically came from very dense and resilient hard woods. Over the years, old growth forests were decimated and ceased to be the primary source for transmission and distribution poles. Today’s rapid growth tree farms now produce, over decades, a pole with somewhat degraded properties; mainly, reduced durability, stiffness, and longevity. This means new wood poles are less robust and do not resist insect infestation or wood rot as well as the older generation poles. Service life is logically shorter. Rapid growth tree farms produce poles that are less robust and do not resist insect infestation or wood rot as well as older generation poles. To enhance pole longevity, today’s wood poles are treated with pentachlorophenol (a known carcinogen) suspended in a light oil (creosote) to enhance pole treatment. This eventually presents a handling and disposal challenge for utilities at the end of a pole’s service life. Environmental regulations now consider treated wood poles as hazardous waste; a significantly more expensive proposition than normal landfill disposal. Wood poles have another vulnerability that is especially problematic in forested areas – they burn. This is where composite poles have a distinct advantage – they resist fire and will not support combustion without the addition of an external heat source. Composite Characteristics While not fireproof, composite poles are extremely fire resistant; especially, when coated with fire retardant. A propane flame can cause a composite pole to smolder with a limited amount of flame when applied directly to the surface of the pole, but as soon as the flame is removed, the composite material ceases to smolder or produce flame. This makes composite poles ideal for deployment in forested areas. More importantly, after exposure to fast moving brush fires, the poles will not likely require replacement and will continue to support the lines and equipment with no loss of strength. The resilience of composites is one of their more desirable features. Composites allow strength parameters to be accurately “dialed-in” during manufacturing to meet the job specification. This saves time and money and eliminates waste. The service life of a composite pole is conservatively rated at 70 years on average. In addition, composite poles are extremely light weight, strong, and do not lose their strength over their lifetime. Industry Acceptance Obviously, any new product or technology offered to the electric power industry needs to be thoroughly tested before it can be deployed to a live grid. To better evaluate new electric power technologies that might enhance grid reliability and/or lower service costs, Southern California Edison (SCE) created a new section on their grid in San Bernardino known as the “Circuit of the Future.” SCE pilot project pultruded transmission pole. Southern California Edison worked closely with a number of composite pole manufacturers to help them design and manufacture a series of composite poles that meet SCE’s needs in terms of strength, durability, serviceability, and service life. Each composite pole company has its own patented method of production, which means each type of pole has a unique set of characteristics. Modular composite pole for SCE’s “Circuit of the Future”. The chemical composition of the resins, types and amounts of E-Glass, winding patterns and tensions vary significantly from one manufacture to another and account for various performance characteristic. These various manufacturing processes are naturally tightly held secrets. Hardware Design Attaching equipment to hollow composite poles, rather than solid wood poles, requires different hardware and methods. In most cases, hardware installation is very straightforward. For instance, rather than drilling holes and then bolting brackets directly into wood, a composite pole requires that a hole be drilled completely through both sides of the pole with the equipment brackets being attached