General Order 95
Section VI
Detailed Construction Requirements for Tower Lines
and Extra High Voltage Lines (Class E Circuits)
61.3 Material and Strength (also see
Section IV
)
A. Material
(1) Tower Members: Tower members shall have a thickness of metal equivalent
to the following:
Galvanized steel: Main corner members, 3/16 inch; other
members, 1/8 inch.
Painted steel: Main corner members, 1/4 inch;
other members, 3/16 inch. All iron or steel members of towers and all hardware
subject to injurious corrosion under the prevailing conditions shall be protected
by galvanizing, painting or other treatment which will effectively retard
corrosion.
(2) Overhead Ground Wires or Lightning Protection Wires: Overhead ground
wires or lightning protection wires shall be galvanized steel cable not less
than 1/4 inch in diameter, or other corrosion resistant material of equal
tensile strength. Where overhead ground wires are not used, effort shall
be made to secure an effectively grounded structure.
(3) Guys and Anchor Rods:
a) Guys: Guys shall be galvanized steel strand not less than 5/16 inch
in diameter, or other corrosion resistant material of equal tensile strength,
or they shall be rolled rods of galvanized steel or other corrosion resistant
material with tensile strength not less than the tensile strength of 5/16
inch diameter galvanized steel strand.
b)
Anchor Rods: Anchor rods shall be galvanized steel not less than
5/8 inch in diameter or shall be of equal strength and durability.
B.
Strength
Where support structures
are used which are not capable of withstanding substantially as great a stress
longitudinally as transversely, longitudinal guying shall be used. The line
as a whole shall be designed so that a failure of an individual support structure
shall not cause successive failures of more than ten additional support structures.