Not many people realize the multiple steps that go into selecting and treating a tree that will become a power pole used to carry information and electricity to homes and businesses across neighborhoods, cities, states, and the country as a whole. To be considered for pole use, trees have to meet certain growth characteristics, like size, a generally straight grain, straightness of the tree, itself, and carry few large branches. Currently, Southern Pine trees are the most often used pole type used in the US Other common types include Douglas-fir, and western Red cedar, which are both used more often in larger transmission poles, such as class H poles.
The power pole installation process is a prerequisite job that requires a set formula of measurements to ensure that the pole is in optimal condition and will withstand decades of use and a variety of weather conditions. Specific criteria are provided by the ANSI in four different categories for a pole to meet acceptability, including processing defects, typically occurring defects, pole shape, and growth characteristics. Manufacturing requirements were put into place to minimize strength loss during the conversion process of tree-to-pole and to maximize the success of any preservation treatments used to extend the service life that would be expected in the pole.
When a new power pole installation is being considered, much thought is given to utility design and placement. The right design and placement can minimize impact on aesthetics to ensure the streets cape view remains intact. Thoughtful design and placement also lends to making the most of available planting space, reduces the need for cutting and trenching and may also reduce extended street sidewalk closings while work is in progress. When installation is done correctly, overall improved citizen safety, as well as improved living conditions and aesthetics can be achieved. In an attempt to follow design optimization, consideration is giving to roadway and parking locations, placement of utility boxes, and Throughway, Frontage, and Extension Zones.
When the skilled craftsmen are responsible for power pole installation have done all the site research and calculations that they need for accurate placement, they will begin the actual groundbreaking for the project. Today, most installers use specialized equipment capable of drilling to specified depths within the earth. The size or class, as indicated above, of a pole depends on the load it will carry, including horizontal winds, vertical loads associated with the transformers, conductors, and other mounted equipment, expected weather type, and wire tension on angled structures. How deeply the pole will be buried varies, depending on ultimate pole height, but usually goes by 10% plus 2 ft. Egypt 6 ft.