Vol. 15—1961 - NorthEastern Weed Science Society

4('2.
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A DECADEOF BRUSHCONl'ROL
R. A. Mann
Tennessee Valley Authority
Chattanooga, Tennessee
During the past decade we have conducted an extensive research program in
right-of-way maintendnce, which has resu~ted in the experimentation and use
of almost every known method, technique, chemical, and type of equipment for
brush control.
Brush control is a major and expensive recurring problem connected with the
transmission of electric energy in the Tennessee Valley region because of the
numerous species of brush and types of terrain, which vary from swamps and .
rolling upland to high plateaus and rugged mountains. The aver-age annual
ra~nfall is more than 50 inches, and the average annua.l temperq.ture is above
60. These factors contribute to luxuriant growth of yegeta.ti",n. The TVA
power system included approximately 12,000 miles of energized transmission
lines at the end of June 1960. About 60 percent of the transmission line
rights-of-way run through wooded areas, resulting in approximately 90,000
acres of brush to be controlled. The right-of-way width varies from 50 to
600 feet, depending on the voltage and the number of circuits; however, the
vast majority of rights-of-way are cleared 100 feet wide.
In the large integrated right-of-way maintenance program associated with
TVA's growing power system, there is a place fer mechanical and chemical
brush control prncedures utilizing many different methods ann equipments.
Mechanical Maintenance
Until recent years mechanical methods were the only effective means of controlling
brush, and even now many utility rights-of-way are maintained only
by mechanical methods. The hand method req,uires large crews using brush
hooks, Kaiser blades, and axes for periodically clearing the brush. It is
usually necessary to reclear every 2 to 4 years. Because of rising labor
costs, the unit cost for the hand method has became increasingly prohibitive,
and improved mechanical devices have evolved. Rotary brush.cutters, having a
3-point hydraulic lift, pulled by small tractors have been used. However,
their use is limited to comparatively level rights-of-w~y haVing only small
brush. They cannot be used in rocky or mountainous terrain, and they will not
clear the brush uniformly cLose to the ground. These ma.chines can be advantageously
used for cutting patrol paths where the gr("lund cover consists of
briars, weeds, and small brush.
The BUshwacker has been successfully ~sed by some utility companies and has
been tried by TVA. This is a large, self-propelled. machine having a large
metal drum with flails attached. This machine pushes and/or cuts brush up to
8 inches in diameter in a 6-foot swath along the rights-of-way. The drum is
located on the front of th!,! machine and is driven by a separate motor at a
high rate of speed. The flail.s splinter the brush to small ~ieces, cutting