RUS BULLETIN 1724E-200 DESIGN MANUAL FOR HIGH VOLTAGE TRANSMISSION LINES ELECTRIC STAFF DIVISION RURAL UTILITIES SERVICE U.S DEPARTMENT OF AGRICULTURE Revised May 2005 UNITED STATES DEPARTMENT OF AGRICULTURE Rural Utilities Service RUS BULLETIN 1724E-200 SUBJECT: Design Manual for High Voltage Transmission Lines TO: All Electric Borrowers, Consulting Engineers and RUS Electric Staff EFFECTIVE DATE: Date of Approval OFFICE OF PRIMARY INTEREST: Transmission Branch, Electric Staff Division FILING INSTRUCTIONS: This bulletin replaces REA Bulletin 1724E-200, "Design Manual for High Voltage Transmission Lines," revised September 1992 AVAILABILITY: This bulletin can be accessed via the Internet at http://www.usda.gov/rus/electric/bulletins.htm PURPOSE: This guide publication is a reference containing fundamental engineering guidelines and basic recommendations on structural and electrical aspects of transmission line design, as well as explanations and illustrations The many cross-references and examples should be of great benefit to engineers performing design work for RUS borrower transmission lines The guide should be particularly helpful to relatively inexperienced engineers beginning their careers in transmission line design CONTRIBUTORS: The following current and former members of the Transmission Subcommittee of the Transmission and Distribution (T&D) Engineering Committee of NRECA Ballard, Dominic, East Kentucky Power Coop., Winchester, KY Burch, John, Florida Keys Electric Coop., Tavernier, FL Heald, Donald, USDA, Rural Utilities Service, Washington, DC Lukkarila, Charles, Great River Energy, Elk River, MN McCall, Charles, Georgia Transmission Company, Tucker, GA Mundorff, Steve, Tri-State Generation & Transmission Association, Inc., Denver, CO Nicholson, Norris, USDA, Rural Utilities Service, Washington, DC Oldham, Robert, Southern Maryland Electric Coop., Hughesville, MD Saint, Robert, National Rural Electric Cooperative Association, Washington, DC Smith, Art, Burns and McDonnell Engineering Co., Atlanta, GA Turner, David, Lower Colorado River Authority, Austin, TX Twitty, John, Alabama Electric Coop., Andalusia, AL _ James R Newby Assistant Administrator Electric Program 09/23/2004 Date Bulletin 1724E-200 Page i TABLE OF CONTENTS CHAPTER - GENERAL CHAPTER - TRANSMISSION LINE DOCUMENTATION CHAPTER - TRANSMISSION LINE LOCATION, ENGINEERING SURVEY AND RIGHT-OF-WAY ACTIVITIES CHAPTER - CLEARANCES TO GROUND, TO OBJECTS UNDER THE LINE AND AT CROSSINGS CHAPTER - HORIZONTAL CLEARANCES FROM LINE CONDUCTORS TO OBJECTS AND RIGHT-OF-WAY WIDTH CHAPTER - CLEARANCES BETWEEN CONDUCTORS AND BETWEEN CONDUCTORS AND OVERHEAD GROUND WIRES CHAPTER - INSULATOR SWING AND CLEARANCES OF CONDUCTORS FROM SUPPORTING STRUCTURES CHAPTER - INSULATION AND INSULATORS CHAPTER - CONDUCTORS AND OVERHEAD GROUND WIRES CHAPTER 10 - PLAN-PROFILE DRAWINGS CHAPTER 11 - LOADINGS AND OVERLOAD FACTORS CHAPTER 12 - FOUNDATION STABILITY OF DIRECT-EMBEDDED POLES CHAPTER 13 - STRUCTURES CHAPTER 14 - GUYED STRUCTURES CHAPTER 15 - HARDWARE CHAPTER 16 - UNDERBUILD APPENDIX A - TRANSMISSION LINE DESIGN DATA SUMMARY SHEET AND SUPPORTING INFORMATION APPENDIX B - CONDUCTOR TABLES APPENDIX C - INSULATION TABLES APPENDIX D - AMPACITY, MVA, SURFACE GRADIENT TABLES APPENDIX E - WEATHER DATA Bulletin 1724E-200 Page ii TABLE OF CONTENTS (CONT) APPENDIX F - POLE DATA APPENDIX G - CROSSARM DATA APPENDIX H - MISCELLANEOUS STRUCTURAL DATA APPENDIX I - RI AND TVI APPENDIX J - INSULATOR SWING TABLES APPENDIX K - SYMBOLS AND ABBREVIATIONS APPENDIX L - SELECTED SI-METRIC CONVERSIONS APPENDIX M- INDEX INDEX OF BULLETINS: Design, System Transmission Facilities, Line Manual ABBREVIATIONS (See Appendix L for Engineering Symbols and Abbreviations) AAAC AAC AACSR ACAR ACSS ACSR ACSR/AW ACSR/SD ACSR/TW ANSI ASTM AWAC BIA BLM CEQ CFR COE DOE DOI EPA EHV EIS EPRI Eq FAA FERC FHA FLPMA All Aluminum Alloy Conductor All Aluminum Conductor Aluminum Alloy Conductor Steel Reinforced Aluminum Conductor Alloy Reinforced Steel Supported Aluminum Conductor Aluminum Conductor Steel Reinforced Aluminum Conductor Steel Reinforced/Aluminum Clad Steel Reinforced Aluminum Conductor Steel Reinforced/Self Damping Aluminum Conductor Steel Reinforced/Trapezoidal Wire American National Standards Institute American Society for Testing and Materials Aluminum Clad Steel, Aluminum Conductor Bureau of Indian Affairs Bureau of Land Management Council on Environmental Quality Code of Federal Regulations Corps of Engineers Department of Energy Department of Interior Environmental Protection Agency Extra High Voltage Environmental Impact Statement Electric Power Research Institute Equation Federal Aviation Agency Federal Energy Regulatory Commission Federal Highway Administration Federal Land Policy and Management Act Bulletin 1724E-200 Page iii ABBREVIATIONS (continued from previous page) (See Appendix L for Engineering Symbols and Abbreviations) FS FWS IEEE M&E LWCF NEPA NESC NPDES NPS NRCS OCF OHGW PL RI REA ROW RUS SHPO SML SPCC T2 TVI TW USC USDA USDI USGS Forest Service Fish and Wildlife Service Institute of Electrical and Electronics Engineers, Inc Mechanical and Electrical Land and Water Conservation Fund Act National Environmental Protection Act National Electrical Safety Code National Pollutant Discharge Elimination System National Park Service Natural Resource Conservation Service Overload Capacity Factor Overhead Ground Wire Public Law Radio Interference Rural Electrification Administration Right-of-Way Rural Utilities Service State Historical Preservation Officers Specified Mechanical Load Spill Prevention Control and Countermeasure Twisted Pair Aluminum Conductor Television Interference Trapezoidal Wire United States Code United States Department of Agriculture United States Department of Interior United States Geological Survey FOREWORD Numerous references are made to tables, figures, charts, paragraphs, sections, and chapters Unless stated otherwise, the tables, figures, charts, etc referred to are found in this bulletin When the reference is not in this bulletin, the document is identified by title and source ACKNOWLEDGEMENTS Figures 9-6 and 9-7 of this bulletin are reprinted from IEEE Std 524-1992, “IEEE Guide to the Installation of Overhead Transmission Line Conductors, Copyright 1992 by IEEE The IEEE disclaims any responsibility or liability resulting from the placement and use in the described manner Figures 4-2, 4-4, 5-2, 5-5 and 11-1 and the table on reference heights (page 4-3) of this bulletin are reprinted from IEEE/ANSI C2-2002, National Electrical Safety Code, Copyright 2002 by IEEE The IEEE disclaims any responsibility or liability resulting from the placement and use in the described manner Figures 11-2a to 11-2d, E-1, E-2, E-3, E-4, and Tables E-2 and E-3 of this bulletin are reprinted from ASCE7-2002, “Minimum Design Loads for Buildings and Other Structures,” American Society of Civil Engineers, Copyright 2003 For further information, refer to the complete rest of the manual (http://www.pubs.asce.org/ASCE7.html?99991330) Bulletin 1724E-200 Page iv LIST OF TABLES Table Number Table Name Brief Comment Page Routing 3-2 3-1 Line Routing Considerations 3-2 Summary of Potential Major Federal Permits Federal permits or Licenses That May Be Required 3-6 4-1 RUS Recommended Design Vertical Clearances of Conductors Above Ground, Roadways, Rails, or Water Surface Vertical clearance 4-6 4-2 RUS Recommended Design Vertical Clearances from Other Supporting Structures, Buildings and Other Installations Vertical clearance 4-8 4-3 RUS Recommended Design Vertical Clearances in Feet Between Conductors Where the Conductors of One Line Cross Over the Conductors of Another and Where the Upper and Lower Conductor Have Ground Fault Relaying Vertical clearance 4-12 5-1 RUS Recommended Design Horizontal Clearances from Other Supporting Structures, Buildings and Other Installations Horizontal clearance 5-2 5-2 Typical Right-of-Way Widths Right-of-way 5-7 6-1 RUS Recommended Vertical Separation in Feet Between Phases of the Same or Different Circuits Attached to the Same Structure Vertical separation of conductors 6-3 7-1 RUS Recommended Minimum Clearances in Inches at Conductor to Surface of Structure or Guy Wires Clearances for insulator 7-4 swing 7-2 Insulator Swing Angle Values in Degrees Angles of swing 8-1 Recommended RUS Insulation Levels at Sea Insulation Level (Suspension at Tangent and Small Angle Structures) 7-6 8-2 Bulletin 1724E-200 Page v Table Number LIST OF TABLES (Continued from previous page) Table Name Brief Comment Page 8-2 Recommended RUS Insulation Levels at Sea Insulation Level (Posts at Tangent and Small Angle Structures) 8-3 8-3 Reduced Shielding Angle Values Shield angles 8-5 8-4 Suggested Leakage Distances for Contaminated Areas Leakage distances 8-10 8-5 Summary of Recommended Insulator Loading Limits Insulator load limits 8-11 9-1 Recommended Minimum Conductor Sizes Min conductor sizes 9-5 9-2 Constants to be Added to the Total Load on a Wire for NESC District Loads Constants 9-8 9-3 Recommended RUS Conductor and Overhead Ground Wire Tension and Temperature Limits Tension and temp limits 9-9 9-4 Direction of Deviation of Sags from Predicted Values when Actual and Assumed (Design) Ruling Span Values are Significantly Different Ruling span and sags 9-12 11-1 NESC Loading Districts Loading Districts 11-2 11-2 Wire Velocity Pressure Exposure Coefficient (kZ) Wire kZ 11-3 11-3 Wire Gust Response Factor, GRF Wire GRF 11-3 11-4 Combined Factor kZ*GRF for Common RUS Wire Heights Wire kZ*GRF 11-4 11-5 Structure kZ, GRF , and Combined kZ GRF Factor kZ, and GRF for structures 11-4 11-6 RUS Recommended Overload Factors and Strength Factors to be Applied to NESC District Loads Load factors and strength factors 11-11 Bulletin 1724E-200 Page vi Table Number LIST OF TABLES (Continued from previous page) Table Name Brief Comment Page 11-7 RUS Recommended Overload Factors and Strength Factors to be Applied to Extreme Wind Loads Load factors and strength factors 11-12 12-1 Classification of Soils Based on Field Tests Soil description 12-2 12-2 Presumptive Allowable Bearing Capacities, ksf Bearing capacity 12-7 12-3 Suggested Ranges of Presumptive Ultimate Bearing Capacities, psf Bearing capacity 12-7 13-1 Designated Stresses for Poles Wood characteristics 13-3 13-2 Designated Stresses for Crossarms Wood characteristics 13-3 13-3 Crossbrace Capacities X-brace 13-15 14-1 Application of Overload and Strength Factors for Guyed Structures (Guys and Anchors) Overload factors 14-2 14-2 RUS Recommended Minimum Clearances in Inches from Conductor to Surface of Structure or to Guy Wires Clearance to guys 14-3 15-1 Strengths for ANSI C135.1 Machine Bolts, Double Arming Bolts and Double End Bolts Bolt strengths 15-9 15-2 Strengths of ASTM A325 Heat Treated, High Strength Bolts Bolt strengths 15-11 15-3 Galvanic Table of Various Metals Galvanic table 15-12 16-1 RUS Recommended Minimum Vertical Clearances to Distribution or Communication Underbuild on Transmission Lines in Feet Clearance to underbuild 16-3 C-1 Flashover Data for Porcelain String 5-3/4” x 10” Standard Suspension Insulators C-2 C-2 Flashover Data For Suspension Polymers (ANSI C29.12-1997) C-3 C-3 Approximate Weights and Lengths of Insulator Strings Using Standard 5-3/4” x 10” Suspension Bells with a Ball Hook C-4 BULLETIN 1724E-200 Page L-2 SELECTED SI-METRIC CONVERSIONS (Continued) LINEAR DENSITY To Convert From pound per foot (lb/ft) pound per inch (lb/in) To kilogram per meter (kg/m) kilogram per meter (kg/m) Multiply by 1.488164 1.785797 E + 01 LOAD CONCENTRATION To Convert From pound per square inch (lb/in2) pound per square foot (lb/ft2) ton per square foot (ton/ft2) To kilogram per square meter (kg/m2) kilogram per square meter (kg/m2) kilogram per square meter (kg/m2) Multiply by 7.03069 E + 01 4.882428 9.071847 E + 02 MASS To Convert From pound (avoirdupois) (lb) To kilogram (kg) Multiply by 4.535924 E - 01 PRESSURE To Convert From kip per square inch (kip/in2) kip per square foot (kip/ft2) newton per square meter (N/m2) pound per square foot (lb/ft2) pound per square inch (lb/in2) To Multiply by pascal (Pa) 6.894757 E + 06 pascal (Pa) 4.788026 E + 04 pascal (Pa) *1.000 pascal (Pa) 4.788026 E + 04 pascal (Pa) 6.894757 E + 03 BENDING MOMENT To Convert From kilogram force meter (kgf-m) kip-foot (kip-ft) pound-foot (lb-ft) *Exact Conversion To Multiply by newton meter (N-m) newton meter (N-m) newton meter (N-m) *9.806650 1.355818 1.355818 Bulletin 1724E-200 Page L-3 SELECTED SI-METRIC CONVERSIONS, (Continued) VELOCITY To Convert From foot per second (ft/s) kilometer per hour (km/h) mile per hour (mi/h or mph) meter per hour (m/h) To Multiply by meter per second (m/s) meter per second (m/s) meter per second (m/s) meter per second (m/s) *3.048 2.777778 4.470400 2.777778 E - 01 E - 01 E - 01 E - 04 VOLUME To Convert From cubic foot (ft ) cubic inch (in3) cubic kilometer (km3) cubic millimeter (mm3) To Multiply by cubic meter (m ) cubic meter (m3) cubic meter (m3) cubic meter (m3) 2.831685 1.638706 *1.000 *1.000 E - 02 E - 05 E + 09 E - 09 TEMPERATURE To Convert From Degrees Fahrenheit ºF Degrees Celsius ºC XºC = 9/5 X + 32 XºF = - 5/9(X – 32) BULLETIN 1724E-200 Page L-4 Blank page Bulletin 1724E-200 Page M-1 Subject INDEX Page Numbers A AAC Aluminum conductor (1350 H-19) AAAC (6201 conductor) AACSR conductor ACAR conductor ACSR conductor ACSR/AW conductor ACSR/SD conductor ACSR/TW ACSS Aeolian vibration Ampacity, conductor Anchors logs plate power screw Armor rods Authorizations AWAC conductor Axial loading, for guyed structures 9-2 9-2 9-4 9-2, 9-3 9-1, 9-2 9-2 9-3 9-4 9-4 9-3, 9-13, 9-14, 15-6 to 15-7 9-5, D-2, D-3 14-2, 14-9 14-9 14-9 14-9 15-1, 15-3, 15-6, 15-7 3-5 9-3 14-4 to 14-8 B Backfill Backswing Bearing capacity Bisector guys Bolt hole, moment reduction due to Buckling Buckling, calculation of buckling loads Building, clearance over Bundled conductors 12-8 7-5 12-6, 12-7 14-1, 14-4, 14-7 F-20, F-21 14-4 to 14-7 14-5 to 14-7, 14-12 4-4, 4-6 to 4-8 15-8 C Calculation of a ruling span Checklist, review of plan and profile Clamp top clamps Clearance at crossings between transmission and underbuild distribution conductors examples of, calculations 9-10 10-15 15-2 10-10, 4-9 to 4-13 16-2, 16-3, 16-4 4-9, 4-10, 4-11, 5-7, 6-5, 6-6, 7-5 Bulletin 1724E-200 Page M-2 Subject INDEX for lines along roads in rural districts for lines over buildings for lines over railroads for lines over swimming pools for sag template horizontal insulator swing minimum horizontal clearance of conductors to objects over water side hill to grain bins to guys to objects under line to rail cars to swimming pools to tall vehicles under differential ice loading vertical, between conductors of different lines at noncrossing situations vertical, between conductors where one line crosses over another vertical, conductors to ground vertical, conductors to ground (underbuild distribution), vertical clearance to underbuild Climbing space Communication underbuild Conductor AAC (1350 H-19 aluminum) AAAC-6201 AACSR ACAR ACSR ACSR/AW ACSR/SD (self-damping) ACSR/TW ACSS ampacity tables AWAC bundled corrosion considerations design for vibration Page Numbers 4-3 4-4, 4-8 4-4, 4-5, 4-6, 4-7 4-5, 4-8 4-4 5-1 to 5-3, Chapter Chapter 13 5-1 to 5-7 4-4, 4-6, 4-7 10-13 5-2 to 5-5 14-3, 7-1, 7-4 4-6, 4-7, 4-8, Chapter 4-4, 4-5 4-5, 4-6, 4-7 4-3 6-6, 6-7 4-10, 4-11 4-9 to 4-13 4-1, 4-2, 4-6, 4-7 16-1, 16-2 16-2, 16-3, 16-6 16-4 16-2, 16-3 9-2 9-2 9-4 9-2, 9-3 9-1, 9-2 9-2 9-3 9-4 9-4 D-2 9-3 15-8 9-4 9-13, 9-14 Bulletin 1724E-200 Page M-3 Subject INDEX design tensions determination of conductor sags and tensions economic considerations extreme ice tension extreme wind tension final unloaded tension initial unloaded tension mechanical loading tables minimum size motion hardware ruling span of related hardware sagging of selection of size selection of type standard loaded tension stringing of swing angle temperature thermal consideration twisted pair (T-2) vibration voltage drop considerations of Contamination, insulation Contraflexure for H-frames Corrosion of hardware Corrosion considerations, conductor Crossarm braces Crossarm data moment capacities crossarm loading chart Crossarm fittings Crossarm, wood, designated stresses Crossbraces Cushioned suspension unit Page Numbers 9-7, 9-8, 9-9 9-15 to 9-16 9-5, 9-6 9-7, 9-8, 9-9 9-7, 9-8, 9-9 9-7, 9-9 9-7, 9-9 B-2 to B-9 9-5 15-6 to 15-8 9-10 to 9-12 15-1 to 15-8 9-18 to 9-19 9-5, 9-6 9-4, 9-5 9-7, 9-8, 9-9 9-17 5-1, 5-6, Chapter 7, 7-3, 7-5, 7-6 4-2, 4-9, 5-1, 16-2 9-5 9-4 9-13, 9-14 9-5 8-7 to 8-10 13-13, 13-14, H-3 15-12 9-4 13-15, 13-16, 13-17 G-2 G-3 15-8, 15-9, 15-10 13-3 13-14, 13-15 9-14, 15-2, 15-6 D Dampers Deadend clamps Deflection, structure Design data summary 9-14, 15-7 15-3, 15-4 5-1, 5-6, 5-8 to 5-11 13-4 to 13-8 2-1 Bulletin 1724E-200 Page M-4 Subject INDEX Design data summary book, suggested outline Design data summary form Design data summary form, instructions for filling out Determining conductor sags and tensions Page Numbers A-10, A-11 A-3, A-4 A-5 to A-9 9-12 to 9-16 E Easements Embedment depths Embedment depths of wood poles Embedment depths of steel/concrete poles Environmental criteria Establishing a ruling span Excessive insulator swing Extreme ice Extreme ice and wind Extreme ice, conductor tension Extreme winds, velocity pressure exposure coefficients gust response factors for 3-3, 3-4, 3-5 to 3-8 12-2 to 12-6 12-2 to 12-4 12-5, 12-6 3-1, 3-5 to 3-8 9-10 to 9-12 7-9, 10-10, 10-11 11-2 11-2, E-4 to E-7 9-8, 9-9 11-2 to 11-7, 11-12 11-3 11-3, 11-4 F Fasteners Fault clearing Field survey, soil Final unloaded conductor tension Fittings Footing resistance Foundation stability 15-8, 15-11 4-1 12-2 9-7, 9-9 15-5, 15-10, 15-11 8-6, 8-7 Chapter 12, 12-3 to 12-7 G Gain plate Galloping Grid gains Gust response factor wire structure Guy attachments Guy strands, strength Guyed structures Guys 15-10 6-7, 6-8, 6-9, 15-8 15-10 11-3, 11-4 11-4 15-11 H-4 10-14, Chapter 14, 16-5, 16-6 Bulletin 1724E-200 Page M-5 Subject bisector clearance to for steel and concrete poles for wood poles force in head and back hold-down (uplift) in-line rated breaking strength of strength factors INDEX Page Numbers 14-1, 14-4, 14-7 14-3, 7-4 14-6 14-6, 14-7 14-2 14-1, 14-4 10-11, 15-8 14-7, 10-13 H-4 14-2, 11-11, 11-12 H Hardware armor rods bolts clamp top clamps conductor motion conductor-related hardware corrosion of crossarm fittings cushioned suspension units dampers deadend clamps fasteners fittings gain plate grid gains guy attachment reinforcing plate spacer fitting splices strain yokes structure-related suspension clamps swing angle brackets tied supports Head and back guys High wind (insulator swing) clearance Hold down guys (uplift) Horizontal clearance recommendations Horizontal separation Horizontal separation recommendations 9-14, 15-1, 15-7 15-9, 15-11, H-4 15-2 9-13, 9-14, 15-6 to 15-8 15-1 to 15-8 15-12 15-10 9-14, 15-2, 15-6 9-9, 9-14, 15-7 15-3, 15-4 15-8, 15-9 15-5, 15-10 15-10 15-10 15-11 15-10 15-10 15-4 15-4 15-8 to 15-12 15-1, 15-2, 15-6 15-10, 15-11 15-2 14-1, 14-4 7-2, 7-3, 7-4 10-11 Chapter 5, 5-1 to 5-7 6-1 6-1, 6-2 Bulletin 1724E-200 Page M-6 Subject INDEX Horizontal span, definition Horizontal span, max as limited by structure strength single pole structures H-frames Page Numbers 7-6, 7-7 13-4 to 13-9 13-12 to 13-27 I Ice loading Ice loading, differential Initial unloaded conductor tension In-line guys Insulation footing resistance high altitude considerations standard RUS levels tables for Insulation contamination Insulator greasing Insulator washing Insulator lengths Insulator load limits porcelain and non-ceramic post, pin, suspension Insulator orientation Insulator swing, charts effect on design excessive formulae for Insulator string flashover data Insulator swing clearance Insulator swing values Insulator weights, suspension Insulators, corrosion of electrical characteristics of horizontal post (porcelain and non-ceramic) horizontal post (special considerations) lengths, suspension load limits of mechanical considerations of post and pin mechanical considerations of suspension porcelain vertical post and pin mounted on 11-2 6-6, 6-7, 11-8 9-7, 9-9 14-7, 10-13 Chapter 8-6, 8-7 8-3, 8-4, 8-5 8-2, 8-3 C-2, C-3 8-7 to 8-10 8-10 8-10 C-4 8-11 to 8-14 8-11 to 8-14 8-8, 8-9 Chapter 7, 10-10, 10-11, 15-8 7-6, 7-8, 7-9, 7-11 to 7-14 7-6 7-9 7-8, 7-9 8-2, 8-3, C-2, C-3 7-1 to 7-5 7-5, 7-6, J-2 to J-3 C-4 15-12 8-2, 8-3 8-1, 8-3, 8-11, 8-12 8-12 C-4 8-11 8-11, 8-12, 8-13 8-11 to 8-14 8-11, 8-12, 8-13 Bulletin 1724E-200 Page M-7 Subject crossarms post suspension types weights, suspension INDEX Page Numbers 8-1 to 8-3, 8-9, 8-12, 8-13 8-1 to 8-3, 8-9, 8-11, 8-12, 8-13 8-1 C-4 L Licenses Lightning Lightning flashover mechanism Line routing considerations Line survey Loading, axial (for guyed structures) Loads extreme wind combined ice and wind (NESC) combined ice and wind (50 yr) ice NESC district loads longitudinal loads Longitudinal loads Longitudinal structure strength 3-5 to 3-8 8-5 to 8-7 8-5 3-1, 3-2 3-3, 3-4 14-4 to 14-9 11-2 to 11-7, 11-12 11-1, 11-2 11-2, E-4 to E-7 11-2 11-1, 11-2 11-8 11-8 10-13, 11-8 M Meteorological data wind velocities and pressures annual extreme winds annual extreme ice/wind maps thunderstorm days per year Moderate wind (insulator swing) clearance Moment capacities for wood poles Moment reduction due to bolt hole E-2 11-2 to 11-4, 11-5 to 11-7 E-4 to E-7 E-8 7-1 to 7-4 F-3, F-5 to F-19 F-20, F-21 N NESC loading districts No wind (insulator swing) clearance O 11-1, 11-2 7-1, 7-3, 7-4 Bulletin 1724E-200 Page M-8 Subject INDEX Offset clipping Overhead ground wire sags and clearances selection of type and size tension limits Overload factors Page Numbers 9-18, 9-19 8-5, 8-6, 9-6 to 9-9, 10-4, 6-3, 6-7 9-7 9-8, 9-9 11-9 to 11-12, 14-2 P Permits Percy Thomas formula Photogrammetry Plan-profile drawings, preparation of Pole, moment capacities Pole classes Pole embedment depth Pole stability direct embedded, wood direct embedded, steel and concrete Pole top assembly, H-frame Pole, weight Poles, wood, designated stresses Post insulator Preservative treatment 3-5 to 3-8 6-4 3-3, 3-4 3-4, Chapter 10 10-1 to 10-4 F-5 to F-19 F-4 12-1 to 12-6 12-2, 12-3, 12-4 12-5 to 12-6 13-15 to 13-18 F-22 13-3 8-1 to 8-3, 8-11, 8-12, 8-13 13-3 R Rail cars, clearance to Reconnaissance and preliminary survey Reference component and tall Vehicles/boats Rerouting RI and TVI Right-of-way calculated width clearing typical width width width for a line directly next to a road width for two or more structures on a single right-of-way Roads, clearances for lines along roads in rural districts Route selection 4-4, 4-5, 4-6, 4-7 3-3 4-3 3-4, 3-5 I-2 to I-6 3-3, 3-5 5-7 to 5-12 3-5 5-7 5-7 5-9 5-10 4-3 3-1, 3-2, 3-3 Bulletin 1724E-200 Page M-9 Subject INDEX Route survey Ruling span calculation of effects of a wrong establishment of Page Numbers 3-3, 3-4, 10-1 9-10, 9-11, 9-12, 10-5, 10-6, 10-13 9-10 9-11, 9-12 9-11 S Sag, overhead ground wire Sag and tension relationships Sag template, curves Sagging of conductors Section properties, (structural) Selection of conductor size Selection of conductor type Self-damping conductor Separation, horizontal between transmission and underbuild distribution conductors Separation, minimum vertical Separation between lines as dictated by minimum clearance between conductors carried on different lines Separation between lines as dictated by minimum clearance of conductors from one line to the supporting structure of another Shielding angle Side hill clearance Single pole structures, a method of structural analysis of Site survey Soil, bearing capacity construction backfill Soils, description of types Spaces and ways accessible to pedestrians only Span, definition of horizontal, definition maximum, as limited by structure strength for single pole structures maximum, as limited by structure strength for H-frame structures 6-7 9-15 10-4 to 10-7 10-5 to 10-7 9-18, 9-19 H-2 9-5, 9-6 9-4 9-3 6-1, 6-2 16-1, 16-2, 16-3, 16-4 6-1 to 6-3 5-10 5-11 8-5, 8-6 10-13 13-4 to 13-8 12-1 12-6, 12-7 12-6, 12-7 12-8 12-2 4-3, 4-6, 4-7 7-7, 10-10, 10-11, 10-12 7-7 13-4 to 13-8 13-12 to 13-27 Bulletin 1724E-200 Page M-10 Subject INDEX maximum, as limited by clearance to underbuild maximum, as limited by conductor separation maximum, as limited by conductor separation under differential ice loading maximum, as limited by galloping maximum possible vertical Splices Standard loaded conductor tension Strain yokes Strength factors Strength of pole top assembly, H-frames Stringing of conductors Structure, designated stresses, wood Structure deflection Structure related hardware Structure spotting Structure strength, longitudinal Structure uplift (H-frame) Structures, general design considerations for steel/concrete general design considerations for wood guyed H-frames, a method of analysis of single pole, a method of analysis of Suspension clamps Suspension insulators Swimming pools, lines over Swing angle bracket Page Numbers 16-3, 16-4 6-1, 6-2, 6-4, 6-5 6-6, 6-7 6-7, 6-8, 6-9 9-14 10-8, 10-10, 10-11, 10-12 15-4 9-7 15-4 11-10, 11-11, 11-12 13-15 to 13-18 9-17 13-3 5-1, 5-6, 5-8 to 5-11, 13-4 to 13-7 15-8 to 15-12 10-7 to 10-14 10-13, 11-8 12-8 Chapter 13 13-2 13-3 Chapter 14, 10-13 13-12 to 13-27 13-4 to 13-12 15-1, 15-2, 15-6 8-1, 8-2, 8-11, 8-12, 8-13 4-5, 4-8 15-10, 15-11 T T2 Conductor Temperature, conductor Thermal considerations, conductor Thunderstorm days, map Tied Supports TVI and RI 9-4 4-2, 4-9, 4-10, 5-1, 16-2 9-5 E-8 15-2 I-2 to I-6 Bulletin 1724E-200 Page M-11 Subject INDEX Page Numbers U Underbuild, addition to existing transmission line clearance between transmission and underbuild distribution conductor distribution neutrals horizontal separation from transmission conductor sag template curves strength requirements vertical clearance to ground Uplift Chapter 16 16-1 16-1, 16-2, 16-3 16-4 16-1, 16-2 10-4 to 10-7 Chapter 11, 16-1 16-1, 16-2, 16-3 10-11, 10-12, 10-13, 12-8, 13-20, 13-21 V V-braces Vehicles, tall, clearance to Velocity pressure exposure coefficient structure wire Vertical separation minimum Vertical span, definition maximum vertical span limited by structure strength for single pole structures maximum limited vertical span limited by structure strength for H-frames Voltage, maximum operating 13-15 to 13-18 4-3 11-4 11-3,11-4 6-1, 6-2 6-3 10-8, 10-10 7-7, 10-10, 10-11 13-9 to 13-12 13-15 to 13-19 4-1 W Wind, annual extreme winds Wind, annual extreme wind and ice Wind, velocities and pressures Wood, preservative treatment Wood, designated stresses for Wood, stress limitations 11-2 to 11-4, 11-5 to 11-7 E-4 to E-7 11-3, 11-4, E-2 13-3 13-3 13-3 Bulletin 1724E-200 Page M-12 Blank Page ... SUBJECT: Design Manual for High Voltage Transmission Lines TO: All Electric Borrowers, Consulting Engineers and RUS Electric Staff EFFECTIVE DATE: Date of Approval OFFICE OF PRIMARY INTEREST: Transmission. .. recommended for transmission lines capable of clearing line-to-ground faults and voltages up to 230 kV For 230 kV, the tables apply for switching surges less than or equal to 2.0; for higher switching... engineers performing design work for RUS borrower transmission lines The guide should be particularly helpful to relatively inexperienced engineers beginning their careers in transmission line design