Pole to Pole – At Least In My Mind
Some time ago, George Gotsis, a Holliston Reporter reader, asked what was happening to telephone poles around town. Researching this question took some time and then the draft fell to the bottom of my document list. Recently the focus on the North Pole and Santa rekindled the story of the Holliston telephone poles (a scary look inside my recall mechanism!).
During the warmer months, a company named Osmose was hired to test the durability of all telephone poles in town. Apparently, some folks were speculating about all manner of conspiracies underway – the truth is much less dramatic and yet most important to Holliston’s electrical infrastructure.
Below is an excerpt from a technical paper explaining how and why such remediation is a win-win.
“As the transmission and distribution infrastructure continues to age and revenues decrease or at best remain steady, utility companies must seek creative and cost-effective solutions to problems that naturally accompany aging assets. The use of repair and restoration products provides utilities with significant economic advantages, and structural and environmental benefits.” . .
“Utility companies have become increasingly aware of the need to inspect their transmission and distribution poles on a cyclical basis. The goal of a routine and methodical inspection and maintenance program is to ensure the structural reliability and safety of power line systems. Identifying problems such as groundline decay and damage is a key component of avoiding dangerous and costly pole failures. Depending on the severity, pole owners may be able to structurally rehabilitate these weakened assets at a fraction of the cost to replace them”. .
“The most common and proven rehabilitation system that helps restore groundline strength to utility poles involves the installation of a single-or in some cases a double-steel member known as a truss. Truss systems are widely used by utilities and are the lowest available cost restoration option for poles with groundline decay. Steel trusses are usually galvanized to reduce corrosion potential. They are driven to pre-defined depths and secured to the pole with high-strength steel banding. By driving a truss and securing it alongside a wood pole, bending loads applied to the pole because of wind pressure, equipment, ice and wire tension are transferred to the truss, which carries the load to the ground-effectively bypassing the decayed or damaged areas. These trusses, when properly sized and oriented, are engineered to have the equivalent strength of the original wood pole. . . Most trusses use high-strength steel.”
“A critical component of this, or any repair, is the application of remedial treatments to arrest the decay. Failing to remedially treat the decay will significantly shorten the life of the repair.”
“The Environmental Benefits of Rehabilitation
It is estimated that as many as four million poles are installed in the U.S. each year. Proper maintenance, along with restoration of in-service poles, can increase average service life by decades and reduce the demand for new poles by many tens of thousands of trees each year. Reducing the need for new poles not only saves trees, it also decreases the consumption of chemical and petroleum carriers used in their manufacture. The typical penta-treated distribution pole contains approximately 6.4 pounds of pentachlorophenol and 28 pounds of diesel oil. Forestalling the replacement of one million penta treated poles each year could save as much as 17 million gallons of fuel oil.”
About the author: Matt Gardner, P.E., is product engineer for Osmose Utilities Services Inc.
The Holliston process went something like this:
Crews dug down about 18” and checked the density of the wood.
Some poles were deemed to be sound and not in need of remediation. These received a medallion affixed to the pole indicated that it was O.K.
Before refilling the dirt at the base of the pole a protective layer of paper was wrapped around the base.
Some poles were determined to be in need of preservative. Holes were bored into the pole at ground-level and the preservative was injected into the wood. A plug was inserted to seal each hole from water penetration.
Some poles needed reinforcement in the form of galvanized metal trusses driven into the ground and tightly strapped to the pole. A coat of brown paint made the truss a little less obvious – and yet we all noticed them pretty quickly sprouting up around town. The truss was in addition to an injection of preservative.
The poles that got the complete treatment (above) were ‘awarded’ several medallions indicating what had transpired in 2020 – as far as Holliston telephone poles are concerned.
The next time you’re out for a fresh air break from isolating, look a little closer at the telephone poles you pass to see what ‘awards’ they have received during the great pole remediation of 2020.