Section 6-73-20 - Loading for electrical transmission lines(a) This section prescribes the method of calculating loadings for electrical transmission lines. The methodology prescribed in this section will apply notwithstanding any provision of the Code to the contrary. The methodology must be applied for lines of 69 kV or 138 kV. At the discretion of the public utility's engineer or team responsible for line design, the methodology may be applied to other voltage classes, depending on the importance and necessity of the line.(b) For parts of the State where the elevation of the line is 6,250 feet or less, no ice loading need be considered. For parts of the State where the elevation of the line exceeds 6,250 feet, a radial thickness of one-half inch of ice, weighing 57 pounds per cubic foot, on all conductors must be considered in computing the vertical and wind loadings.(c) Temperature considerations are as follows:(1) For all locations in the State, less than 2,000 feet above sea level: (A) The temperature at the time of maximum loading is assumed to be 50°F;(B) The normal temperature for computing erection conditions is 75°F; and(C) The maximum temperature for computing sags and clearances is assumed at 212°F.(2) For elevations greater than 2,000 feet, the temperatures at the 2,000-foot level are reduced incrementally as the elevation rises, as follows:(A) The temperature at maximum loading at 2,000 feet (50°F) is reduced by 10°F per thousand feet in excess of 2,000 feet; provided, that this temperature must not be lower than 0°F;(B) The normal temperature for computing erection conditions at 2,000 feet (75°F) is reduced by 3°F per thousand feet in excess of 2,000 feet; provided, that this temperature must not be lower than 60°F; and(C) The maximum temperature for computing sags and clearances is assumed at 212°F.[Eff APR 23 2007] (Auth: HRS § 269-6) (Imp:HRS § 269-6)