General Order 64
Section VII
Detail Construction Requirements – Tower Lines
72 Materials.
Tower
members shall have thickness of metal not less than the following:
Galvanized steel: Legs, 3/16 inch; other members, 1/8 inch.
Painted steel: Legs, ¼ 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.