Vegetation management is a specialized field that goes far beyond the trimming of trees. Vegetation management involves right-of-way ground clearance, as well as, line clearance issues. However, for overhead distribution facilities, the lineman normally only has to resolve tree trimming concerns. Tree trimming must be completed in a manner that is environmentally acceptable. The reader is encouraged to review ANSI Z133.1, Pruning, Trimming, Repairing, Maintaining, and Removing and Cutting Brush-Safety Requirements standard for tree care.

Line Clearance Objectives. Line clearance is preventive line maintenance to ensure that the utility's service to its customers is not interrupted as a result of interference with conductors or circuit equipment by growing trees. Elements include removal of dangerous trees and overhangs, trimming to clear the conductors, and clearing transmission right-of-way. Natural tree growth and storm-tossed branches can ground or break distribution and transmission lines, interrupting electric service and endangering the public. The trimming process is intended to anticipate such a possibility by removing this hazard. Lines are checked and cleared on a planned time cycle. The amount of clearance sought should provide hazard-free operation for at least 2 years. It should be accomplished while maintaining the health and beauty of the trees involved, the goodwill of property owners and public authorities, and the safety of the trimming crew and the public.

Clearing the Right-of-Way. Practically all overhead lines will traverse through some brush or timberlands. Even lines built in the Middle West, an area generally thought of as level prairie, may...