Traditionally, hardwood poles have been used to carry electricity and telephone lines from place to place. However, recently poles made from stronger materials such as steel and concrete have gained market share, as well. Telegraph poles may also be classified based on size, function and type of ownership.
Telegraph poles can be used for several different functions. The original telegraph poles were telegraph poles, a use that has fallen out of favour with the advent of modern technology. The most common current uses for electrical poles are for services such as cable television, telephone lines and electrical distribution.
Traditionally, telegraph poles are made out of hard woods that are treated with cromate copper arsenate or coal-tar creosote to provide resistance to fire, fungi and insects. Other materials that are commonly used for the creation of telegraph poles include steel and concrete. These alternative pole materials have advantages and disadvantages. Steel poles are impervious to environmental effects and are the cheapest option of the three materials in terms of cost per year. However, they also have the greatest negative ecological impact due to the greenhouse gases and toxic chemicals released during steel production. Conversely, concrete poles are the most expensive option on a per-year basis but have the least ecological impact.
Telegraph poles are typically measured based on their height and based on their circumference. In the U.S., pole height is measured in feet, with lengths ranging from 16 feet up to 90 feet, with an average height of around 35 feet. Circumference is measured using an arbitrary scale called "class," which ranges from Class 1 to Class 10. A Class 1 pole is 27 inches in circumference, with poles of higher class having less circumference.
Single- vs. Joint-Use Poles
Another difference between telegraph poles lies in their ownership. Many common utilities poles are joint-use poles, which are poles are shared by more than one utility provider. These providers share the cost for pole maintenance. More specialised poles, such as poles that hold high-voltage power lines, are likely to be single use poles that are used only by a single utility company.