File:American hydroelectric practice; a compilation of useful data and information on the design, construction and operation of hydroelectric systems, from the penstocks to distribution lines (1917) (14576978227).jpg

Identifier: americanhydroele00tayl (find matches)
Title: American hydroelectric practice; a compilation of useful data and information on the design, construction and operation of hydroelectric systems, from the penstocks to distribution lines
Year: 1917 (1910s)
Authors: Taylor, William T. (William Thomas), b. 1877 Braymer, Daniel Harvey, 1883-1932
Subjects: Hydroelectric power plants
Publisher: New York, McGraw-Hill Book Company, inc.
Contributing Library: Northeastern University, Snell Library
Digitizing Sponsor: Boston Library Consortium Member Libraries

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es, as 12 pounds per square foot of projected area forgrade A, 7 pounds for grade B, and 4 pounds for grade C, the pressure being computed DATA, REFERENCE TABLES AND SYSTEM DIAGRAMS 403 for the poles and towers without ice covering, while conductors are assumed to be coveredwith a layer of ice one-half inch in radical thickness. Lightning protection wires and trolley contact conductors are included in computing transverse stresses. (b) In regions of medium loading the transverse pressure shall be taken as two-thirdsthat for heavy loading districts and in regions of light loading the transverse pressure shallbe assumed to be two-thirds that for medium loading districts, that is, four-ninths ofthat for heavy loading districts. (c) A map of the United States showing the territory falling into each class of loadingis given in Fig. 258 (Appendix A of Code). (See also rule 222b.) The localities in thedifferent groups are classed according to the relative prevalence of high wind velocity and
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Fig. 258. -Territorial Division of the United States with Respect to Loading on ElectricTransmission Lines thickness pf ice which accumulates on wires, Ught loading being for places where no iceof appreciable thickness ever accumulates on wire. Where high-wind velocities are frequent in a given place the loading for that place may be classed aaheavy even though ice does not accumulate to any greater extent than at some other place having less severewinds which has been classed as a medium loading district. (d) In the absence of any action by the administrative authority fixing the loadingsfor any given jurisdiction the classification of loadings shown on the map Fig. 258(Appendix A of Code) shall be considered to apply unless the party or parties respoi\siblefor the lines concerned assume some modification of the same, based upon local exper-ience or weather records, or both. These modifications shall be subject to review bythe administrative authority. 232. Calculation op Loads Upon

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