UNITED STATES DEPARTMENT OF AGRICULTURE

Rural Utilities Service

BULLETIN 1724E-153 

RD-GD-2001-39

SUBJECT: Electric Distribution Line Guys and Anchors

TO: RUS Electric Borrowers and RUS Electric Staff

EFFECTIVE DATE: Date of Approval 

OFFICE OF PRIMARY INTEREST: Distribution Branch, Electric Staff Division

FILING INSTRUCTIONS: This bulletin replaces REA Bulletin 61-5, “Guide for the 

Design of Guys and Anchors for Grade C Distribution Construction,” and Chapter V-5 of 

REA Bulletin 160-2, “Mechanical Design Manual for Overhead Distribution Lines.” 

Discard Bulletin 61-5. File this new bulletin with 7 CFR 1724. 

AVAILABILITY: This bulletin is available on the Rural Utilities Service website at 

page at http://www.usda.gov/rus/electric/index.htm. 

PURPOSE: This guide bulletin provides information needed to properly design guying 

for conductors attached to wood distribution poles. To this end, the bulletin contains 

data, equations, and sample calculations. The bulletin also contains information 

regarding standard RUS anchor and guying assemblies and their component parts to 

assist the user in the proper selection and installation of these assemblies. 

April 25, 2001 

Blaine D. Stockton Date

Assistant Administrator 

Electric Program

Disclaimer: The contents of this guidance document does not have the force and effect of law and is not 

meant to bind the public in any way. This document is intended only to provide clarity to the public 

regarding existing requirements under the law or agency policies. 
Bulletin 1724E-153

Page 2

TABLE OF CONTENTS

1. Introduction ...................................................................................................................... 4

2. Anchors, Anchoring, and Soils........................................................................................ 5

3. Guy Wires ......................................................................................................................... 7

4. RUS Guy Assemblies and Hardware.............................................................................. 7

5. Loading on Poles and Guy Assemblies........................................................................... 9

6. NESC (1997 Edition) Guying Requirements.................................................................11

7. Determine Weakest Component Part........................................................................... 11

8. Installation of Guy and Anchor Assemblies................................................................. 11

9. Equations for Loading Moments on Pole......................................................................13

10. Calculation of Horizontal Loads on Guy Assemblies...................................................14

11. Calculation of Permitted Loads on Guy Assemblies................................................... 15

12. Calculation of Minimum Guy Lead...............................................................................17

13. Methodology for Multiple Guys.....................................................................................18

14. Example Guy Assembly Calculation .............................................................................18

15. Determination of Pole Class to Support Vertical Loads............................................. 22

Exhibit A: Conductor Loadings (1997 NESC)......................................................................... 27

Exhibit B: Extreme Wind Loadings (1997 NESC) ................................................................. 28

Exhibit C: Contributors............................................................................................................. 29

TABLE OF TABLES

Table 2-1: RUS Standard Distribution Anchor Assemblies.......................................... 5

Table 2-2: Soil Classifications.......................................................................................... 6

Table 3-1: Guy Wire Strength Data ................................................................................ 7

Table 4-1: RUS Guying Assembly Units......................................................................... 8

Table 4-2: Standard Washers – Loads Allowed............................................................. 8

Table 5-1: Overload Factors for Poles, Guys, Anchors, Etc. ........................................ 9
Bulletin 1724E-153

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INDEX:

ANCHORS:

Calculations 

Guide for Design

DESIGN, SYSTEM:

Guys and Anchors Guide

GUYING AND ANCHORING:

Guide for Design

MATERIALS AND EQUIPMENT:

Guys and Anchors Design Guide

ABBREVIATIONS

ACSR Aluminum conductor, steel reinforced 

ANSI American National Standards Institute

BIL Basic Impulse Insulation Level

IEEE Institute of Electrical and Electronic Engineers, Inc. 

NESC National Electrical Safety Code

RUS Rural Utilities Service

UNITS OF MEASURE

m meter or meters (metric base unit of length) 

in inch or inches (1 inch = 0.0254 meters)

in2 square inches (1 square inch = 0.0006452 square meters) 

ft foot or feet (1 foot = 0.3048 meters)

ft2 square feet (1 square foot = 0.092903 square meters)

cmil circular mils (1 circular mil = 5.067075 x 10 –10 square meters)

kcmil 1,000 circular mils (1 kcmil = 5.067075 x 10 –6 square meters) 

g gram or grams (metric base unit of weight)

kg kilogram or kilograms (1,000 grams = 1 kilogram) 

lbs pounds (1 pound = 0.45359 kilograms)

ft-lbs foot-pounds (feet x pounds), (a measure of torque or angular force)
Bulletin 1724E-153

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ELECTRIC DISTRIBUTION LINE GUYS AND ANCHORS

1. INTRODUCTION

1.1 Guyed Structures: Guys and anchors are installed at distribution line deadends, line 

angles and at points of unbalanced conductor tensions. Unbalanced conductor tensions 

occur where the conductor size is changed or where there is an appreciable change in the 

ruling span. A guy assembly needs to be designed to hold the entire horizontal 

component of the load being applied on the structure in the opposite direction of the guy 

assembly. A wood pole is used as a strut and supports the vertical components of all 

loads on the pole including the vertical forces due to the tension contributed by the guy.

While a pole may have sufficient strength to withstand side strain of angles up to

5 degrees for small conductors, it is usually advisable to install a guy and anchor to 

prevent the pole from leaning. The use of pole keys in place of guys should be avoided 

wherever possible. RUS highly discourages the use of push-brace poles in lieu of 

downguys and anchors.

1.2 Scope of Bulletin: This guide bulletin lists all of the standard RUS distribution guy 

and anchor assemblies and their permitted loads and holding power, respectively. The 

bulletin also discusses the component parts of guy assemblies and their strengths. 

Installation guidelines are provided for guy and anchor assemblies.

Within this bulletin are the derivation of the equations required to calculate: loading 

moments, guy resisting forces for several guying situations, guy loads, minimum guy 

leads, and required pole class to support vertical loads. Example problems using these 

equations are also presented.

1.3 National Electrical Safety Code: The bulletin references rules and presents selected 

strength and overload factors required by the 1997 Edition of the National Electrical 

Safety Code (NESC) for certain guy calculations. At the time this bulletin was written, 

the 1997 Edition was the latest edition of the NESC. Periodically the NESC is updated 

and revised. Users of this bulletin should use the rules and data, as may be revised and 

renumbered, from the most recent edition of the NESC. Copies of the NESC may be 

obtained from the Institute of Electrical and Electronic Engineers, Inc., (IEEE) at the 

following address:

IEEE Customer Service

445 Hoes Lane, PO Box 1331

Piscataway, NJ 08855-1331
Bulletin 1724E-153

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2. ANCHORS, ANCHORING, AND SOILS

2.1 Types of Anchor Assemblies: Selection of the proper type of anchor assembly 

depends upon the soil conditions where the anchor is to be installed. (See Table 2-2: Soil 

Classification). Many utility systems standardize on one or two sizes of anchors of the 

types most suitable for the soil conditions found in their service areas. The surface area 

and holding power of the anchor assemblies depicted in RUS specifications and drawings 

for distribution line construction are shown in the following tables:

Table 2-1: RUS Standard Distribution Anchor Assemblies

Anchor Type RUS Designation Minimum Area 

(square inches)

Designated 

Maximum Holding 

Power (lbs) *

Expanding

F1.6 90 6,000

F1.8 100 8,000

F1.10 120 10,000

F1.12 135 12,000

Screw 

(Power 

Installed)

F2.6 90 6,000

F2.8 100 8,000

F2.10 120 10,000

F2.12 135 12,000

Plate

F3.6 90 6,000

F3.8 100 8,000

F3.10 120 10,000

F3.12 135 12,000

Swamp

Helix Diameter 

(inches)

F6.6 10 6,000

F6.8 12 8,000

F6.10 15 10,000

Service

Anchor Type

F4.1 Expanding 2,500

F4.2 Screw 2,500

* Note: The “designated maximum holding power” assumes the use of the proper 

anchor rod type and diameter and proper installation in Class 5 soils.

Expanding anchors are the most commonly used anchors on rural distribution lines. 

Screw (power installed) anchors are most commonly used when loose soils are known to 

be prevalent near the ground line with firmer soil underneath. Likewise, swamp anchors 

are needed to penetrate firm soil under swamps and wetlands. Plate anchors are most 

commonly used when heavy conductors are installed on rural distribution lines. Service 

anchors are usually used to guy service drops and secondary conductors.
Bulletin 1724E-153

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2.1.1 Rock anchors are to be installed and used where solid rock is encountered. Only 

one guy is to be attached to a rock anchor. Where more than one guy is required, 

separate anchors are to be installed for each guy at a minimum of 2 feet apart and, where 

practical, in a direct line with the conductors. The holding power of rock type anchors is 

highly variable and depends on type of rock, installation procedures and the grout used.

2.1.2 Log type anchors are acceptable for use on RUS distribution systems. The 

materials and construction details for these types of anchors can be found in RUS 

Bulletin 1728F-810, “Electric Transmission Specifications and Drawings, 34.5kV 

through 69 kV.”

2.2 Anchor Strength Requirements: Table 261-1A of the 1997 NESC specifies strength 

factors (equal to 1.0 for both Grade B and Grade C construction) with which the 

established holding power of anchors are to be multiplied. Rule 264 of the 1997 NESC 

requires that an anchor and rod assembly have an ultimate strength not less than that of 

the guy(s) attached to it.

2.3 Soil Classifications: The following table defines the commonly accepted soil classes 

and their descriptions.

Table 2-2: Soil Classifications

CLASS ENGINEERING DESCRIPTION

0 Sound hard rock, unweathered

1 Very dense and/or cemented sands; 

coarse gravel and cobbles

2 Dense fine sand; very hard silts and

clays

3 Dense clayed sand, sand, gravel;

very stiff to hard silts and clays

4 Medium dense sandy gravel; very stiff

to hard silts and clays

5 Medium dense coarse sand and sandy gravels;

stiff to very stiff silts and clays

6 Loose to medium dense fine to coarse sand;

firm to stiff clays and silts

7 Loose fine sand; alluvium; loess;

soft-firm clays; varved clays; fill

8 Peat; organic silts; inundated silts; fly ash
Bulletin 1724E-153

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3. GUY WIRES

The following table illustrates the most common sizes and types of stranded guy wire 

used for guying conductors on distribution lines. The last column of the table shows the 

maximum load permitted on a guy wire which is 90 percent of its rated breaking strength 

per the strength factors (for both Grade B and Grade C construction) specified in

Table 261-1A of the 1997 Edition of the NESC. Guy wires and guy assemblies need to 

be able to hold all of the horizontal forces (loads) acting on the pole multiplied by the 

appropriate overload factors found in Section 25 of the 1997 NESC.

Table 3-1: Guy Wire Strength Data

Type Strand Size

Breaking 

Strength 

(lbs)

Permitted Load 

(0.9 x Rated 

Strand Breaking 

Strength) (lbs)

Siemens Martin Steel

1/4 in 3,150 2,835

3/8 in 6,950 6,255

7/16 in 9,350 8,415

High Strength Steel

1/4 in 4,750 4,275

3/8 in 10,800 9,720

7/16 in 14,500 13,050

Aluminum Clad Steel

6 M 6,000 5,400

8 M 8,000 7,200

10 M 10,000 9,000

12 M 12,500 11,250

A more complete list of stranded guy wires is included in section “y” of RUS Information 

Publication 202-1, “List of Materials Acceptable for Use on Systems of RUS 

Electrification Borrowers.”

4. RUS GUY ASSEMBLIES AND HARDWARE

4.1 RUS Guy Assemblies: Standard RUS distribution guying assemblies include both 

the guy wire and the hardware to connect the guy wire to the pole. For analysis purposes, 

this bulletin discusses the guy wires and the pole attachment hardware separately and 

refers to the pole attachment hardware as the guying assembly. Table 4-1: RUS Guying 

Assembly Units presents the RUS standard distribution guy assemblies included in 

Bulletin 1728F-803, “Specifications and Drawings for 24.9/14.4 kV Line Construction.” 

Multiple downguys consist of two or more guy assemblies installed in parallel and 

attached to one or more anchors as may be needed. The last two columns on the right 

side of Table 4-1 itemize the permitted loads allowed by RUS standards on each guy 

assembly. The permitted loads shown are the calculated strengths of the assemblies, as 

designated by RUS, multiplied by the strength factor of 0.85 as required in the 1997 

NESC. All wind and conductor tension loads acting on guy assemblies need to be 

multiplied by the appropriate overload factors as found in Section 25 of the 1997 NESC.
Bulletin 1724E-153

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Table 4-1: RUS Guying Assembly Units

Guying Assembly Type RUS

Designation

Permitted Loads (lbs) *

Horizontal @ 45

Degrees

Single Down Guy (Through Bolt) E1.1 5,000 7,100

Single Overhead (Through Bolt) E1.02 6,600 -

Single Down Guy – Heavy Duty 

(Through Bolt) E2.1 7,400 10,500

Single Down Guy (Wrapped Type) E3.1 11,900 16,800

Single Down Guy – Large Conductors 

(Pole Band Type) E4.1L 8,500 12,000

* Permitted load is the lesser of loads shown or permitted load of guy wire (See Table 

3-1: Guy Wire Strength Data).

Permitted loads are designated capacities multiplied by 0.85, the 1997 NESC 

strength factor.

Greater permitted loads (strengths) are required for guy angles less than 45 degrees.

4.2 Hardware: The following hardware is needed, in certain specific combinations, to 

attach guy wires to distribution poles:

 Machine bolts and washers (with nuts and locknuts), or thimble eye bolts and/or 

thimble eye nuts;

 Guy attachments (guy hook or pole band type, or guy hooks and guy plates); and

 Guy deadends (types include: 3-bolt clamp, U-bolt clamp, offset guy clamp, and 

automatic and formed deadends).

4.3 Washers: An area of concern with guy attachment hardware is the crushing of wood 

pole fibers where the washer under the bolt head is in contact with the pole. This washer 

usually carries the full horizontal component of the working load of the guy assembly. 

RUS standards allow no more than 910 pounds per square inch of compression for 

washers abutting wood poles and crossarms. Table 4-2: Standard Washers – Loads 

Allowed, shows the maximum compression load allowed by RUS standards for washers 

abutting wood poles. (The area of the bolt hole is subtracted from the total surface area 

of the washer.)

Table 4-2: Standard Washers – Loads Allowed

Washer Size and Type Approximate Area 

(square inches)

Load Allowed 

Abutting Pole (lbs)

2-1/4 in. Square, Flat 4.6 4,200

3 in., Square, Curved 8.6 7,800

4 in. Square, Curved 15.6 14,200
Bulletin 1724E-153

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5. LOADING ON POLES AND GUY ASSEMBLIES

5.1 Conductor Tension and Wind/Ice Loading: Guy-anchor assemblies, in conjunction 

with poles, need to support the sum of the following loads:

 Conductor tension loads,

 Maximum wind/ice loads on the conductors (as defined by NESC Loading Districts),

 Extreme wind loads (only when top of pole is 60 feet or more above ground),

 Wind loads on the supporting structure (pole), and,

 Wind loads on the material and equipment attached to the structure.

All of the above-calculated loads need to be multiplied by the appropriate overload factor 

as specified in Section 25 of the 1997 NESC. The tables in Exhibit A and Exhibit B at 

the end of this bulletin provide the information required to calculate wind/ice loading for 

each NESC loading district and on bare conductors commonly installed on distribution 

lines. The greater of either the (1) wind/ice loads or, (2) extreme wind loads, but not 

both, need to be added to the sum of the loads. The wind load on materials and 

equipment attached to a pole can usually be ignored.

5.2 NESC Overload Factors: The following table of overload factors has been adapted 

from Table 253-1 of the 1997 NESC:

Table 5-1: Overload Factors for Poles, Guys, Anchors, Etc. 

(Use with Table 261-1A Strength Factors)

Overload Factors

Grade B Grade C

Rule 250B Loads

Vertical Loads 1.50 1.50

Transverse Loads

Wind 2.50 2.20

Wire Tension 1.65 1.30

Longitudinal Loads

In General 1.10 No Requirement

At Deadends 1.65 1.30

At Deadends (for guys) 1.65 1.10

5.3 Pole Loading: Guyed poles may be considered to act as struts and need to support 

the vertical component of the loads cited in Section 5.1 plus any additional vertical 

component of forces that may be induced by the guys. It is assumed that a pole will 

adequately hold transverse (horizontal) loads not in line with the guy(s). However,

unguyed transverse loads may cause the pole to lean, thus, the installation of additional 

guys (sideguys) may be desirable.
Bulletin 1724E-153

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5.4 Application of Loading per Type of Guy Assembly: Standard RUS distribution 

construction utilizes dead-end, line angle bisector, and occasionally overhead types of 

guys. The loads that guy assemblies need to hold for the different types of guying 

arrangements are discussed below.

5.4.1 Single dead-end guy assemblies are installed in line with the conductors they 

(horizontally) support on the opposite side of the pole. Dead-end guy assemblies need to 

support conductor tension loads and the maximum wind/ice (or extreme wind) loads on 

the conductors. These loads are calculated and then multiplied by the appropriate NESC 

overload factors. For calculation purposes:

 Wind loads are assumed to be horizontal and perpendicular to the conductors (which 

is considered to be the worst case wind/ice loading condition);

 Wind/ice loads are added to the conductor tension loads in line with the guy 

assembly; and

 Wind loading on the pole and the attached equipment and material is not added to the 

sum of the loads.

5.4.2 Double dead-end assemblies consist of two dead-end assemblies that are each 

guyed in the opposite direction of the conductors. The tension and wind/ice loads are 

calculated independently for each guying assembly using the same procedure as 

discussed for single dead-end assemblies. Likewise, at double dead-end assemblies on 

tangent poles, the loads and guying requirements are determined independently for each 

set of conductors attached to the pole. In the case of tangent dead-end assemblies, only 

the difference of the two loads needs to be guyed. Thus, the calculations assume guy 

assemblies in two directions, however only (preferably) one guy assembly needs to be 

installed.

5.4.3 Junction poles and tap poles usually have one or more single dead-end guy 

assembly(s). The calculations required to determine the loading and strength 

requirements for the guys are performed independently for each set of conductors 

attached to the pole using the same methodology and assumptions discussed in Section 

5.4.2.

5.4.4 Bisector guy assemblies are installed at line angles where there is no change in 

conductor tension. The conductor may be attached to the pole with a pole-top angle 

assembly or a double dead-end assembly up to approximately 30 degrees. The guy 

assembly(s) is installed in line with the bisector of the line angle. The total loading on a 

bisector guy assembly is the vector sum of the following:

 The transverse conductor loading tension,

 The wind/ice (or extreme wind) loading on all attached line conductors, and

 The wind loading on the pole, and, if critical, the wind loading on the materials and 

equipment on the pole.
Bulletin 1724E-153

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The wind direction is assumed to be parallel with the direction of the line angle bisector. 

The appropriate NESC overload factors have to be applied to all of the above loads.

6. NESC (1997 EDITION) GUYING REQUIREMENTS

6.1 Grade of Construction: As a minimum, guys and anchors are to be of the same 

grade of construction as the conductors which they (horizontally) support. For standard 

RUS distribution construction, a minimum of NESC Grade C construction is required in 

accordance with 7 CFR Part 1724. However, guys and anchors which support 

distribution lines and communications circuits attached to or underbuilt on transmission 

line structures (poles) are to be designed and constructed to Grade B construction 

requirements. The NESC may also require Grade B construction for other specific 

situations and locations. Section 24 of the 1997 NESC sets forth the requirements and 

exceptions for grades of construction.

6.2 Strength Requirements: Section 26 of the 1997 NESC sets forth the strength 

requirements and strength factors for guys and anchors. Table 261-1A (to be used with 

the overload factors of Table 253-1) requires a strength (multiplication) factor of 0.85 be 

applied to the pole attachment hardware and 0.9 be applied to guy wires for Grade C 

construction.

7. DETERMINE WEAKEST COMPONENT PART

Determination of the weakest component part of a guying-anchoring system, as may be 

derated by application of the necessary NESC strength factors (and perhaps age), is 

essential in proper line design and the use of guys and anchors. The strength or holding

power of the combined guy and anchor is only as strong as its weakest component part. 

Each factor listed below needs to be analyzed separately and compared to ascertain that 

even the weakest component part of the guying system is stronger than the induced load.

 Holding power of anchors (see Sections 2.1 and 2.2)

 Soil classification (see Sections 2.3 and 8.3)

 Strength of guy wires (see Section 3)

 Maximum permitted load for guy assemblies, hardware and washers (see Sections 

4.1, 4.2, and 4.3, respectively)

8. INSTALLATION OF GUY AND ANCHOR ASSEMBLIES

8.1 Guy Assemblies: Guy and anchor assemblies need to be installed before conductors 

are installed. These assemblies should be located as far as possible from highways, 

driveways and paths where they might pose an obstacle to expected traffic. If possible, 

guy wires should be installed such that the angle formed between the guy and the pole is 

45 degrees or more. (45 degrees occurs when the height of guy attachment is equal to the 

length of the guy lead [the distance from the pole to the anchor rod], i.e., a 1 to 1 ratio.)
Bulletin 1724E-153

Page 12

8.2 Guy Markers: Rule 264E of the 1997 NESC requires a conspicuous guy marker be 

installed where a guy is exposed to vehicle or pedestrian traffic. RUS specifies, on the 

assembly drawings in Bulletin 1728F-803, a guy marker be installed on all down guys.

8.3 Anchor Assemblies: In RUS Bulletin 1728F-803, under “Construction Specifications 

for Anchoring,” RUS specifies the following for standard distribution lineconstruction:

 “All anchors and rods shall be in line with the strain and shall be installed so that 

approximately 6 inches of the rod remains out of the ground. In cultivated fields or 

other locations, as deemed necessary, the projection of the anchor rod above earth 

may be increased to a maximum of 12 inches to prevent burial of the rod eye. The 

backfill of all anchor holes must be thoroughly tamped the full depth.

 After a cone anchor has been set in place, the hole shall be backfilled with coarse 

crushed rock for 2 feet above the anchor and tamped during the filling. The 

remainder of the hole shall be backfilled and tamped with dirt.

 The maximum load with overload factors transferred to the anchor should not exceed 

the designated maximum holding power given in the design parameters on the anchor 

assembly drawing. The rating is coordinated with the maximum holding power of 

average, Class 5, soil conditions.

 When the anchor is used in poorer soils, the holding power of the anchor should be 

derated. A suggested guide is to derate by 25 percent in Class 6 soil and by

50 percent in Class 7 soil. For Class 8 soil it is usually necessary to use swamp 

anchors or power driven screw anchors which can penetrate the poor soil into firmer 

soil.”

8.4 Grounding of Guy Wires: Rules 92C2, 93C5, and 215C2 of the 1997 NESC specify 

the requirements for the grounding of guy wires. With only a few exceptions, all guy 

wires are required to be grounded by being bonded to each other and bonded to the 

system neutral. RUS specifies that an anchor-bonding clamp be installed between all 

down guys and anchors. RUS considers it to be non-standard construction when guy 

wires are not effectively bonded and grounded. RUS recommends the installation of 

stainless steel or galvanized steel ground rods, or the replacement of existing copper 

ground rods with stainless steel or galvanized steel ground rods, instead of isolating down 

guys to mitigate the cathodic corrosion of anchors.

8.5 BIL Levels and Raptor Protection: RUS strongly recommends that a minimum 

basic impulse insulation level (BIL) of 300 kV be maintained on all distribution pole tops 

to mitigate the possibility of lightning flashovers. Furthermore, RUS recommends that a 

minimum of 24 inches of vertical separation be maintained between energized conductors 

and (grounded) guys to lessen the danger of electrocution to raptors. Both of the above 

objectives can be achieved with the installation of guy strain insulators, when needed, as 

shown on RUS standard construction drawing “E5.1G”. Guys still need to be grounded 

by bonding them to one another and to the system neutral below the guy strain insulator.
Bulletin 1724E-153

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K 

9. EQUATIONS FOR LOADING MOMENTS ON POLE

The total ground line moment, Mg (measured in ft-lbs), on a pole equals the sum of all the 

load moments applied to the pole due to wind on the conductors, the pole, and the 

equipment, plus tension loads imposed by the conductors. Thus:

Mg = ShMc + Mt + Mp + Me EQ 9-A

Where:

Sh = Horizontal wind span (1/2 the sum of adjacent spans) (ft)

Mc = Summation of moment loads due to wind on each conductor 

expressed as moment per unit length of span (ft-lb/ft)

= Fow{Σ(WcHc)}cos(θ/2) EQ 9-B

Mt = Summation of moments due to the tension in each conductor, if 

there is a line angle (ft-lb)

= 2Fot{Σ(TcHc)}sin (θ/2) EQ 9-C

Mp = The moment due to wind on the pole (ft-lb)  2Ct + Cg 

= Fow Wp



 c

 Hp

2

EQ 9-D

Me = The moment due to wind on the material and equipment on the 

structure (ft-lb)

And where:

Fow = NESC overload factor for wind loads

Fot = NESC overload factor for longitudinal (tension) loads

Hp = Height of pole above ground (ft)

Hc = Height of each conductor attachment above groundline (ft)

Wc = Wind load per unit length of each conductor (lb/ft)

Wp = Wind load per unit area surface of pole (lb/ft2

)

Tc = Tension in each conductor (lb)

θ = Line angle at pole

Ct = Pole circumference at top (in)

Cg = Pole circumference at ground line (in)

Kc = Calculation constant = 72π

One or more of the force moment components may be omitted from Equation 

EQ 9-A if its contribution is insignificant as compared to the other force

components. The moment due to wind on the material and equipment on the pole,
Bulletin 1724E-153

Page 14

Me, can usually be omitted because the cross-sectional area of the equipment and 

material multiplied by the wind force is very small compared to the other forces 

acting on the pole. Other legitimate omissions are discussed in Section 10.

10. CALCULATION OF HORIZONTAL LOADS ON GUY ASSEMBLIES

10.1 Total Horizontal Load: The total horizontal load on a guy assembly is determined 

by dividing the total ground line moment Mg (see EQ 9-A) by the height of the guy 

attachment above the ground using the following equation:

Mg

Gh = H

EQ 10-A

g

Where:

Gh = Horizontal component of loads on guy assembly (lbs)

Mg = Summation of ground line moments of load forces (ft-lbs) (EQ 9-A)

Hg = Height of guy attachment (or average of multiple guy attachments) 

above the groundline (ft)

Substituting EQ 9-A for Mg into Equation EQ 10-A yields:

G  Sh Mc + Mt + M p + Me  EQ 10-B

h =  

 Hg 

The terms use in EQ 10-B are defined in Section 9. The computation is simplified and 

the results are conservative if, in the calculation of Mc (EQ 9-B), the cosine of θ/2 is set 

at 1.0 for all values of θ. This practice is recommended for manual calculations. Also, if 

insignificant, the wind loading on the pole’s material and equipment, Me, can be deleted.

10.2 Horizontal Loads on Bisector Guy Assemblies: Equation 10-B is used to calculate 

the horizontal loads exerted on bisector guy assemblies. Note that the NESC overload 

factors have been applied. The horizontal permitted load of the guy assembly to be used 

(see Table 4-1: RUS Guying Assembly Units) needs to be greater than the total horizontal 

loads of Gh calculated in EQ 10-B. The angle θ, (used when substituting EQ 9-B and EQ 

9-C into Mc and Mt above, respectively), is the line angle. It is assumed that the wind 

blows in a direction parallel to the bisector guy.

10.3 Horizontal Loads on Dead-End Guy Assemblies: Equation 10-B is used as the 

basis to calculate the horizontal loads exerted on dead-end guy assemblies. As explained 

in Section 5.4.1, the calculated loads acting on a guyed dead-end pole consist of the 

longitudinal conductor tension linearly added to the wind/ice (or extreme wind) loading
Bulletin 1724E-153

Page 15

on (perpendicular to) the conductors. This methodology simulates the worst case 

condition. Thus, the cos(θ/2) in Equation EQ 9-B and the sin(θ/2) in EQ 9-C are each set 

to unity (1.0). The equation used to calculate the horizontal loads on a single dead-end 

guy assembly is:

G =  Sh Mc + Mt

 EQ 10-C

h  

 Hg 

Where:

Mc = Fow [Σ(WcHc)] EQ 10-D

Mt = Fot [Σ(TcHc)] EQ 10-E

Sh = 1⁄2 the span length of the conductor deadending on the pole (ft) 

(The remaining terms are defined in Section 9 in Equation EQ 9-A)

However, under some circumstances, the wind (only) loading on the pole and the 

attached material and equipment may be greater than the wind/ice loading on the 

conductors. In such cases it is assumed that the wind direction is the same as the 

conductor longitudinal tension. Therefore, the following equation is used to calculate the 

horizontal loads on a single dead-end guy assembly.

G =  Mt + M p + Me  EQ 10-F

h  

 Hg 

The terms in the above equation are also defined in Section 9. The horizontal permitted 

load of the guy assembly to be used (see Table 4-1: RUS Guying Assembly Units) needs 

to be greater than the total horizontal load, Gh, calculated by either method above.

10.4 Other Dead-End Guy Assemblies: At double dead-ends, multiple dead-ends, 

junction poles, and tap poles, the total horizontal loads, and subsequently the guying 

requirements, need to be determined independently for each dead-end assembly on the 

pole. The horizontal loads acting on each guy assembly are calculated using the above 

assumptions and Equation EQ 10-C or Equation EQ 10-F for each dead-end assembly.

11. CALCULATION OF PERMITTED LOADS ON GUYASSEMBLIES

The total load on the guy attachment hardware, the guy wire and the anchor assembly is 

calculated by using the following equation.

Gr = Gh

sin φ EQ 11-A
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H 2 + L 2

g g

Where:

Gr = Total guy load (lbs) (on guy assembly, guy wire, and anchor assembly)

Gh = Total horizontal load on guy assembly (lbs) (Equation EQ 10-A)

φ = Guy wire angle with respect to pole (degrees)

The loads applied to the guy and anchor assembly have previously been multiplied by the 

appropriate NESC overload factors in the calculation of Gh in Equation EQ 10-B. 

However, the NESC strength factors have not been applied in Equation EQ 11-A. 

According to Table 261-A of the 1997 NESC, the load, Gr , calculated in Equation

EQ 11-A should be multiplied by 0.85, 0.9, and 1.0 to yield the permitted loads for guy 

assemblies, guy wires, and anchor assemblies, respectively. Note that RUS has already 

multiplied the designated loads for anchors, guy wires, and guy assemblies by the above 

strength factors and listed the resulting permitted loads in Table 2-1: RUS Standard 

Distribution Anchor Assemblies, Table 3-1: Guy Wire Strength Data, and Table 4-1: 

RUS Guying Assembly Units, respectively.

The permitted loads (capacities) of guy assemblies and guy wires and the holding power 

of anchors each need to be greater than total load, Gr, calculated in Equation EQ 11-A, to

adequately support the conductor tension and wind loads and meet the requirements of 

the 1997 NESC.

Since the down guy assembly forms a right triangle:

F 2 = H 2 + L 2 and sinφ = Lg

g g g

g

Where:

Lg = Guy lead, or distance from pole to anchor rod (ft)

Hg = Height of guy attachment above ground (ft)

Fg = Length of guy wire (ft)

Then:

sinφ = Lg

And Equation EQ 11-A can also be written as:

EQ 11-B

Gr = Gh

g

F

H g

2 + L 2

g

L
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Assuming a 1:1 guy slope, or φ is equal to 45°, the resultant guy load or tension is:

Gr = 1.414 Gh EQ 11-C

12. CALCULATION OF MINIMUM GUY LEAD

While it is recommended that a 1:1 guy slope be used wherever possible, in some 

instances it is necessary to determine the minimum allowable guy lead for various guy 

and anchor arrangements.

The minimum allowable guy lead to the average anchor position is given by:

  Gh 

Lga = H g tanarcsin  EQ 12-A   Gu Fg





  

Where:

Lga = Minimum allowable guy lead (ft)

Hg = Guy attachment height (ft)

Gh = Horizontal load at guy attachment point (lbs) (Equation EQ 10-A)

Gu = Least of: guy wire breaking strength, designated strength of guy 

assembly, or total anchor holding power (each in lbs)

Fg = NESC strength factor ( Table 261-A of 1997 NESC)

If the permitted loads of RUS anchors, guy wires, and guy assembles are used (Table 2-1: 

RUS Standard Distribution Anchor Assemblies, Table 3-1: Guy Wire Strength Data, and 

Table 4-1: RUS Guying Assembly Units, respectively), then Fg should be set to 1.0 

because RUS has already included the 1997 NESC strength factors in the aforementioned 

tables.

Minimum guy leads should be used only when it is not possible to obtain a 1:1 or greater 

guy slope. Always use the longest possible guy wire lead length to obtain the maximum 

strength from the guy assembly. It is common practice to increase calculated minimum 

leads from six inches to one foot to allow for wind loading on structure accessories and 

for construction tolerances. Short guy leads and the resulting greater downward loads on 

the bolt holding the guy assembly to the pole may cause the pole to split.
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13. METHODOLOGY FOR MULTIPLE GUYS

Multiple guys and anchors are required where the strength of one guy assembly or one 

anchor is not adequate for the load. Multiple guys may be placed two or more in line 

with the longitudinal tension according to RUS construction specifications, or if required 

by field conditions, spread apart with the anchors installed side-by-side. The 

recommended minimum separation between anchors is 5 feet in soils and 2 feet in rock.

Multiple guy attachments on a pole are relatively short distances apart for most 

distribution structures. If this is the case, then the simplest method for calculating guy 

loads is to assume that all of the guys are just one assembly, attached to the pole at one 

point and attached to one anchor. The pole attachment is assumed to be the average 

height above ground of all of the actual guy attachments. The anchor is assumed to be 

the average distance from the pole of all of the actual anchor locations. The calculations 

are then made for a single guy and anchor using the equations given previously.

To determine the minimum guy leads required for multiple guys, calculate the total load 

at the average guy attachment point. Then divide this load by the number of guys and 

calculate the required guy lead to the average anchor location.

14. EXAMPLE GUY ASSEMBLY CALCULATION

14.1 Given Information: Assume that a RUS standard VC3.2L (25 kV, Suspension 

Angle, Large Conductors), three-phase, pole-top assembly needs to be constructed at a 

line angle (θ) of 30 degrees. The assembly is installed on a class 40-5 Southern Yellow 

Pine pole. The phase conductors are 266.8 kcmil (26/7) ACSR with a 1/0 (6/1) ACSR 

neutral. One-half the sum of the adjacent spans (Sh) is 400 feet. Four (4) standard RUS 

down guy assemblies and two (2) standard RUS anchor assemblies are to be used to hold 

the conductor loads. NESC Grade C construction is to be used and the pole is situated in 

the NESC light loading district.

14.2 Statement of Problem: Determine the loads that the guy and anchor assemblies 

need to hold, and subsequently determine the adequate standard RUS assemblies that 

should be used for the above theoretical construction.

14.3 Tabulation of Data:

Pole Data:

Lp = 40 ft (height of pole)

Hp = 34 ft (height above ground) 

Lg = 6 ft (bottom to ground line) 

Ct = 19 in (circumference at top)

Cg = 31 in (circumference at ground line)

Kc = 72π (calculation constant)
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(1997) NESC Data: (See Section 9)

Wp = 9 lbs/ft2 (Table 250-1)

Fow = 2.2 (Table 253-1)

Fot = 1.3 (Table 253-1)

Fg = 0.9 (Table 261-1A)

Conductor Data

Conductor Wc (lbs/ft) Wv, (lbs/ft) Tc, lbs (40 % Ultimate Strength)

266.8 kcmil 0.4815 0.3673 4,500

1/0 0.2985 0.1452 1,750

Conductor Attachment Heights: (VC3.2L), (Center of brackets from top of pole)

Top (A) Phase = 1.0 ft ( = 33 ft from groundline)

Middle (B) Phase = 5.0 ft ( = 29 ft from groundline)

Bottom (C) Phase = 9.0 ft ( = 25 ft from groundline)

Neutral = 13.0 ft ( = 21 ft from groundline)

Guy Assembly Attachment Heights: (VC3.2L), (From top of pole)

Top Phase = 2.5 ft ( = 31.5 ft from groundline)

Middle Phase = 6.5 ft ( = 27.5 ft from groundline)

Bottom Phase = 10.5 ft ( = 23.5 ft from groundline)

Neutral = 14.5 ft ( = 19.5 ft from groundline)

Average guy attachment height:

Hg = 31.5 + 27.5 + 23.5 + 19.5

4

Hg = 25.5 ft

14.4 Wind Moment Load on the Pole Surface:

(Use Equation EQ 9-D)

M = (F )(W

)

(2Ct + Cg )

H 2

p ow p   p

 Kc 

= (2.2)(9)((2)(19) + 31)  (34) 2



 72π 

= 6,982 lb-ft
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14.5 Wind Moment Load on the Conductors:

(Use Equation EQ 9-B)

Mc = Fow [Σ(HcWc)] cos θ/2

Phase HcWc

A (33.0)(0.4815)

B (29.0)(0.4815)

C (25.0)(0.4815)

= 15.89

= 13.96

= 12.04

ft − lb / ft 

ft − lb / ft 

ft − lb / ft

N (21.0)(0.2985) = 6.27 ft − lb / ft

∑(HcWc ) = 48.16 ft − lb / ft

Mc = (2.2)(48.16)(cos 15°)

= 102.34 ft-lb/ft

14.6 Total Horizontal Moment Load Due to Conductor Tensions:

(Use Equation EQ 9-C)

Mt = (2)(Fot)[Σ(HcTc)]sin(θ/2)

Phase HcTc

A (33.0) (4500) = 148,500 ft-lb

B (29.0) (4500) = 130,500 ft-lb

C (25.0) (4500) = 112,500 ft-lb

N (21.0) (1750) =

Σ HcTc =

36,750 ft-lb

428,250

Mt = (2)(1.3)(428,250)(sin 15°)

= 288,182 ft-lb

14.7 Total Horizontal Load on Guy Assemblies:

(Use Equation 10-B)

Gh = (400)(102.34) + 288,182 + 6,982

25.5

= 13,180 lbs.

14.8 Total Load on Guy Assemblies: The total load on the guy assemblies, assuming an 

average 1:1 guy slope, is calculated with Equation EQ 11-C.

Gr = (1.414)(13,180) = 18,639 lbs
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14.9 Average Load on Each Guy Assembly: The average load on each guy assembly, 

using 4 down guys and assuming each has a 1 to 1 guy slope is:

18,639 = 4,660 4

lbs

14.10 Permitted Loads on, and Required Strength of Guy Assemblies: The average 

load calculated above (which has been previously multiplied by the appropriate NESC 

overload factors), should not exceed the permitted load on each guy assembly. The 

permitted load on a guy assembly is determined by multiplying its designated strength by 

its appropriate NESC strength factor of 0.85 as found in Table 261-1A of the 1997 

NESC. (See Section 4.1.) Conversely, the required strength of the guy assembly is 

determined by dividing the total (in this case, average) load by the appropriate NESC 

strength factor. Thus, for this example,

required (or designated) strength is:

4,660 = 5,482

0.85 lbs (at 45 degrees)

14.11 Selection of Guy Assembly: Based on the calculations above, the guy assembly 

has to have a permitted load (strength) of 4,660 pounds at 45 degrees or equivalently, a 

designated strength of 5,482 pounds. Any of the standard RUS down guy assemblies, as 

listed in Table 4-1: RUS Guying Assembly Units, are adequate to hold the conductor 

tension and wind loads as calculated above. However, for large conductor applications, 

such as used in this example, RUS recommends the use of heavy-duty guy assemblies, 

specifically E2.1 with a permitted load of 10,5000 pounds at 45 degrees.

14.12 Permitted Loads on, and Strength of Guy Wires: Similar to guy assemblies, the 

permitted load (strength) of each guy wire also has to be equal to or greater than the 

average load of 4,660 pounds at 45 degrees calculated above. The designated strength of 

the guy wire is also determined by dividing the (average) total load by the NESC strength 

factor of 0.90 as found in Table 261-1A of the 1997 NESC. Therefore, for the guywires;

required (or designated) strength is:

4,660 = 5,178 lbs.

0.90

14.13 Selection of Guy Wires: 3/8 inch Siemens-Martin Steel guy wires, with a 

permitted load of 6,255 pounds (see Table 3-1: Guy Wire Strength Data) would be 

adequate for the loads calculated above. Because the guy wires are holding large 

conductors, RUS recommends that 7/16 inch Siemens-Martin Steel guy wire (permitted 

load equals 8,415 pounds) be used.

14.14 Permitted Load on Anchors: The required holding power of each anchor is 9,320 

pounds (18,639 pounds divided by 2) assuming that that the total load is equally split 

between the anchors. The permitted loads on anchors is equal to their designated 

maximum holding power because the strength factor (Table 261-1A of the 1997 NESC) 

for anchor is 1.0.
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14.15 Selection of Anchors: Any of the standard RUS anchor assemblies rated at 10,000 

pounds or more (see Table 2-1: RUS Standard Distribution Anchor Assemblies) may be 

used. However, anchors rated at 12,000 pounds or more are recommended in this case as 

a measure of safety and to better match the larger guy assemblies and guy wires that are 

recommended.

14.16 Minimum Average Guy Lead: Determine the minimum average guy lead, 

assuming the following recommended RUS standard assemblies are used:

 Guy assemblies – E2.1 (permitted load = 4 x 10,500 = 42,000 lbs)

 Guy wire – 7/16 inch Siemens-Martin (permitted load = 4 x 8,415 = 33,660lbs)

 Plate anchors – F3.12 (permitted load = 2 x 12,000 = 24,000 lbs)

From the calculations, the anchors are the limiting component part of this example 

guying arrangement, and thus is used in the design calculations. Use Equation EQ 12-A 

to determine the minimum average guy lead.

  13,182 

Lga = (25.5) tanarcsin

(24,000) 

 = 16.76 ft

  

Note that the average guy attachment height of 25.5 feet was previously calculated in 

Section 14.3. Also, the NESC strength factor was not used in the denominator in the 

above equation because it had already been applied to the anchor to yield its permitted 

load. After adding 0.5 foot tolerance and rounding up the next whole foot, the minimum 

lead becomes:

Lga = 18 ft

The spacing between anchors should not be less than 5.0 feet, i.e., each anchor should be

2.5 feet from the average lead length calculated above and in line with the line angle 

bisector. If the guy lead lengths need to be further reduced, then select guy assemblies, 

guy wires, and/or anchor assemblies with greater permitted loads, or increase the number 

of anchors. The calculation is then repeated. However, RUS does not recommend guy 

lead lengths of less than 15 feet because on the tendency of the pole to split where the 

through bolt holds the guy assembly.

15. DETERMINATION OF POLE CLASS TO SUPPORT VERTICAL LOADS

15.1 Column Strength of Poles: The column strengths of poles at guyed locations 

should be examined for their ability to sustain loads due to the vertical weight of the 

conductors, equipment, and the vertical component of the load supported by the guys. A 

guyed pole acts as a column sustaining these axial loads. A pole acting as a column 

becomes unstable when the axial force becomes large enough to cause largelateral
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2

 

deflections which might significantly add to the moment loads contributed by conductors, 

ice, and equipment installed on the pole.

15.2 Assumptions and Safety Factor: The American Institute of Timber Construction 

suggests that the critical section of a guyed pole is one-third the distance from the point 

of guy attachment to the groundline. In column strength calculations this section is 

assumed to be where the pole strength is most critical. A minimum factor of safety of 1.5 

(based on Table 253-1 of the 1997 NESC) should be applied to the loads in the 

computations because of the various assumptions that need to be made.

15.3 Critical Vertical Load: In general, the critical axial load for a pole acting as a 

column is calculated by using the following formula:

πEA 2

Pcr

Where:

= EQ 15-A

Fv Ka (Ku H gb )

Pcr = Critical buckling axial load (lbs)

E = Modulus of elasticity of wood ( = 1,800,000 lbs/in2

)

A = Cross section area of pole at two-thirds of the distance from the groundline 

to the bottom guy attachment (in2)

Ka = Conversion constant ( = 576 /ft2 )

Hgb= Height of bottom guy attachment above ground (ft)

Ku = The theoretical coefficient of unbraced length

= 0.7 for bisector guying

= 2.0 for dead-end guying

Fv = Safety Factor ( = 1.5 minimum)

To determine the area of the pole at the critical point, A, solve the following equation:

A = 1  (C  b − Ct )(H p − 0.667Hgb ) 

2

+ Ct 

EQ 15-B 4π  Lp − Lb



Where:

Cb = Circumference of pole 6 feet from the butt (in)

Ct = Circumference of pole at top, (in)

Hgb= The distance from groundline to the bottom guy (ft)
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Hp = Pole height above ground, (ft)

Lb = Bottom of pole to ANSI classification point (= 6 ft)

Lp = Pole height (ft)

15.4 Actual Vertical Loads: The actual vertical loads on the pole are the vertical 

(vector) component of the loads on the guy wire(s) plus the weight of the conductors plus 

the weight of the material and equipment installed on the pole. Gv, the vertical 

component of the load contributed by guy wire is calculated using the following 

equation:

G = (Sh )(M c ) + Mt + M p + Me

v L

EQ 15-C

g

Where:

Mc, Mt, Mp and Me are groundline moments as defined in Section 9 (ft-lb)

Lg = Length of guy lead (ft)

Sh = 1/2 the sum of adjacent spans (ft)

All overload factors should be set equal to 1.0 when performing the calculations to 

determine Gv in Equation EQ 15-C. (If groundline moments have previously been 

calculated using overload factors, such as in Equation EQ 10-A, then it is only necessary 

to divide these previously calculated moments by the overload factors.) The moment due 

to wind on the material and equipment on the pole, Me, is included in the calculations 

only if the material and equipment has sufficient cross-section area to have appreciable 

impact on the wind moment.

Wc, the vertical load (lbs) due to the weight of the conductors is calculated using the 

following equation:

Wc = (Sv)(Σ Wv) EQ 15-D

Where:

Sv = Distance between the low point of sags of the adjacent spans (ft)

Wv = Loaded vertical force (weight) of conductors per unit length (lb/ft)

Where spans are relatively short, the error will be small if the horizontal wind span, Sh, is 

substituted for Sv. The weight of crossarms, braces, insulators, and the pole above the 

bottom guy attachment point can usually be neglected in calculations for distribution

poles.
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



t





15.5 Required Pole Class: Pcr was defined in Section 15.3 as the critical buckling axial 

load of a pole. If (Gv+Wc)≤Pcr, then the selected pole class is adequate; otherwise the 

pole class needs to be increased until (Gv+Wc)≤Pcr istrue.

15.6 Example Calculation for Vertical Loads: Determine the critical axial load for the 

guyed pole in the example problem in Section 14. Use the previous data provided, the 

results of the previous calculations and the following data regarding a standard 40 foot, 

Class 5, Southern Yellow Pine pole.

Pole Data:

Fb = 8,000 lb/in2 (designated fiber stress)

Hp = 34 ft (height above ground)

Hgb = 19.5 ft (height to bottom guy attachment)

Lg = 6 ft (bottom to ground line)

Lb = 6 ft (bottom to ANSI classification point)

Ct = 19 in (circumference at top)

Cb = 31 in (circumference at ANSI classification point)

Cg = 31 in (circumference at ground line)

Using Equation EQ 15-B:

A = 1  (Cb − Ct )(H p − 0.667H gb ) 

+ C 



4π  Lp − Lb



A = 1 (31−19)(34 − 0.667×19.5)  2

+ 19

4π  40 − 6 

= 55.49 in2

Using Equation 15-A:

πEA 2

Pcr =

Fv Kc (Ku H gb )

Pcr = (π)(1,800,000)(55.49)2

(1.5)(576)(0.7×19.5)2

= 108,161 lbs

2

2
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Use Equation EQ 15-D, substitute Sh for Sv, and solve for Wc: 

Wc = (400) [(3 x 0.367) + (1 x 0.145)] = 498 lbs

Use Equation 15-C and solve for Gv. Use the values of Mc, Mt and Mp previously used

in the guy strength calculations, but divide each value by the appropriate overload 

capacity factor to reduce the factor to one.

G v =  ( 400





)( 102

2 .2

. 43 ) +288182

1 .3

+

6982

2 .2

 ÷ 6



Gv = 40,579 lbs

Gv + Wc = 40,579 + 498 = 41,077 lbs

Therefore, the pole has adequate strength for vertical axial loads.

The calculations immediately above will demonstrate that for most distribution guy 

designs, axial loading will not be a problem if a 1:1 guy slope is used and the poles are 

equal to or one class larger than the normal tangent pole class. Computations should be 

made where unusually tall poles require guying. Generally, reducing a guy lead by onehalf will approximately double the axial load; using one-fourth of the normal guy lead 

will increase the pole’s axial load by a factor of approximately four.
EXHIBIT A: CONDUCTOR LOADINGS (1997 NESC)

Light Medium Heavy

Name Size Strand

Swanate 4 7/1 0.0670 0.1928 0.1622 0.2247 0.2523 0.5379 0.5379 0.4190 0.9818 2,360 0.257 0.0411

Sparrow 2 6/1 0.0913 0.2370 0.1934 0.2673 0.2720 0.5814 0.5989 0.4387 1.0423 2,850 0.316 0.0608

Sparate 2 7/1 0.1067 0.2438 0.2060 0.2855 0.2750 0.5964 0.6199 0.4417 1.0611 3,640 0.325 0.0654

Raven 1/0 6/1 0.1452 0.2985 0.3819 0.3467 0.2993 0.6580 0.7036 0.4660 1.1439 4,380 0.398 0.0968

Quail 2/0 6/1 0.1831 0.3353 0.4320 0.3998 0.3157 0.7094 0.7719 0.4823 1.2102 5,310 0.447 0.1221

Pigeon 3/0 6/1 0.2309 0.3765 0.4917 0.4647 0.3340 0.7723 0.8539 0.5007 1.2899 6,620 0.502 0.1537

Penguin 4/0 6/1 0.2911 0.4223 0.5629 0.5439 0.3543 0.8491 0.9520 0.5210 1.3853 8,350 0.563 0.1939

Waxwing 266.8 18/1 0.2894 0.4568 0.5907 0.5565 0.3697 0.8681 0.9789 0.5363 1.4162 6,880 0.609 0.2210

Partridge 266.8 26/7 0.3673 0.4815 0.6556 0.6446 0.3807 0.9486 1.0774 0.5473 1.5084 11,300 0.642 0.2436

Merlin 336.4 18/1 0.3653 0.5130 0.6798 0.6557 0.3947 0.9653 1.1015 0.5613 1.5363 8,680 0.684 0.2789

Linnet 336.4 26/7 0.4630 0.5408 0.7619 0.7649 0.4070 1.0664 1.2222 0.5737 1.6501 14,100 0.721 0.3070

Pelican 477.0 18/1 0.5180 0.6105 0.8506 0.8488 0.4380 1.1551 1.3350 0.6047 1.7656 11,800 0.814 0.3955

Hawk 477.0 26/7 0.6570 0.6435 0.9696 1.0015 0.4527 1.2990 1.5014 0.6193 1.9241 19,500 0.858 0.4354

Osprey 556.5 18/1 0.6040 0.6593 0.9441 0.9550 0.4597 1.2599 1.4614 0.6263 1.8900 13,700 0.879 0.4612

Dove 556.5 26/7 0.7660 0.6953 1.0845 1.1319 0.4757 1.4278 1.6533 0.6423 2.0737 22,600 0.927 0.5083

Kingbird 636.0 18/1 0.6910 0.7050 1.0372 1.0610 0.4800 1.3645 1.5864 0.6467 2.0131 15,700 0.940 0.5275

Grosbeak 636.0 26/7 0.8750 0.7425 1.1976 1.2605 0.4967 1.5548 1.8014 0.6633 2.2197 25,200 0.990 0.5808

Drake 795.0 26/7 1.0940 0.8310 1.4238 1.5162 0.5360 1.8081 2.0938 0.7027 2.5086 31,500 1.108 0.7264

Tern 795.0 45/7 0.8960 0.7973 1.2493 1.3042 0.5210 1.6044 1.8678 0.6877 2.2904 22,100 1.063 0.6674

6201 Aluminum Alloy Conductors

Azusa 123.3 7 0.1157 0.2985 0.3701 0.3172 0.2993 0.6361 0.6741 0.4660 1.1195 4,460 0.398 0.0968

Anaheim 155.4 7 0.1459 0.3353 0.4156 0.3626 0.3157 0.6807 0.7347 0.4823 1.1789 5,390 0.447 0.1221

Amherst 195.7 7 0.1857 0.3765 0.4689 0.4175 0.3340 0.7347 0.8067 0.5007 1.2495 6,790 0.502 0.1537

Alliance 246.9 7 0.2318 0.4223 0.5317 0.4846 0.3543 0.8003 0.8927 0.5210 1.3337 8,560 0.563 0.1939

Butte 312.8 19 0.2936 0.4815 0.6140 0.5709 0.3807 0.8862 1.0037 0.5473 1.4432 11,000 0.642 0.2456

Canton 394.5 19 0.3703 0.5408 0.7054 0.6722 0.4070 0.9858 1.1295 0.5737 1.5668 13,330 0.721 0.3099

Darien 559.5 19 0.5252 0.6435 0.8806 0.8697 0.4527 1.1804 1.3696 0.6193 1.8031 18,800 0.858 0.4394

Elgin 652.4 19 0.6124 0.6953 0.9765 0.9783 0.4757 1.2878 1.4997 0.6423 1.9314 21,800 0.927 0.5124

Flint 740.8 37 0.6754 0.7433 1.0543 1.0612 0.4970 1.3718 1.6025 0.6637 2.0345 24,400 0.991 0.5818

Greeley 927.2 37 0.8704 0.8310 1.2534 1.2926 0.5360 1.5993 1.8702 0.7027 2.2979 30,500 1.108 0.7282

0.0” ice, 9 Lb Wind 0.25” Ice, 4 Lb Wind 0.50” ice, 4 Lb Wind

K=0.05 K=0.20 K=0.30

Vert. Trans. Total Vert. Trans. Total Vert. Trans. Total Ultimate Diam. X-Area

Lb/Ft Lb/Ft Lb/Ft Lb/Ft Lb/Ft Lb/Ft Lb/Ft Lb/Ft Lb/Ft Strength In. Sq. In.

ACSR Conductors

Bulletin 1724E-153

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EXHIBIT B: EXTREME WIND LOADINGS (1997 NESC)

13 Lbs 16 Lbs 21 Lbs 26 Lbs 31 Lbs 6 Lbs

Vert. 

Lb/Ft

Trans. 

Lb/Ft

Total 

Lb/Ft

Trans. 

Lb/Ft

Total 

Lb/Ft

Trans. 

Lb/Ft

Total 

Lb/Ft

Trans. 

Lb/Ft

Total 

Lb/Ft

Trans. 

Lb/Ft

Total 

Lb/Ft

Trans. 

Lb/Ft

Swing 

Angle

Name Size Strand

ACSR Conductors

Swanate 4 7/1 0.0670 0.2784 0.2864 0.3427 0.3492 0.4498 0.4547 0.5568 0.5608 0.6639 0.6673 0.1285 78.35

Sparrow 2 6/1 0.0913 0.3423 0.3543 0.4213 0.4311 0.5530 0.5605 0.6847 0.6907 0.8163 0.8214 0.1580 59.98

Sparate 2 7/1 0.1067 0.3521 0.3679 0.4333 0.4463 0.5688 0.5787 0.7042 0.7122 0.8396 0.8463 0.1625 65.71

Raven 1/0 6/1 0.1452 0.4312 0.4550 0.5307 0.5502 0.6965 0.7115 0.8623 0.8745 1.0282 1.0384 0.1990 53.88

Quail

Pigeon

2/0

3/0

6/1

6/1

0.1831

0.2309

0.4843

0.5438

0.5177

0.5908

0.5960

0.6693

0.6235

0.7080

0.7823

0.8785

0.8034

0.9083

0.9685

1.0877

0.9857

1.1119

1.1548

1.2968

1.1692

1.3172

0.2235

0.2510

50.67

47.39

Penguin 4/0 6/1 0.2911 0.6099 0.6758 0.7507 0.8051 0.9853 1.0274 1.2198 1.2541 1.4544 1.4833 0.2815 44.04

Waxwing 266.8 18/1 0.2894 0.6598 0.7204 0.8120 0.8620 1.0658 1.1043 1.3195 1.3509 1.5733 1.5996 0.3045 46.46

Partridge 266.8 26/7 0.3673 0.6955 0.7865 0.8560 0.9315 1.1235 1.1820 1.3910 1.4387 1.6585 1.6987 0.3210 41.15

Merlin

Linnet

336.4

336.4

18/1

26/7

0.3653

0.4630

0.7410

0.7811

0.8262

0.9080

0.9120

0.9613

0.9824

1.0670

1.1970

1.2618

1.2515

1.3440

1.4820

1.5622

1.5264

1.6293

1.7670

1.8626

1.8044

1.9193

0.3420

0.3605

43.11

37.90

Pelican 477.0 18/1 0.5180 0.8818 1.0227 1.0853 1.2026 1.4245 1.5158 1.7637 1.8382 2.1028 2.1657 0.4070 38.16

Hawk 477.0 26/7 0.6570 0.9295 1.1383 1.1440 1.3192 1.5015 1.6389 1.8590 1.9717 2.2165 2.3118 0.4290 33.14

Osprey 556.5 18/1 0.6040 0.9523 1.1277 1.1720 1.3185 1.5383 1.6526 1.9045 1.9980 2.2708 2.3497 0.4395 36.04

Dove

Kingbird

556.5

636.0

26/7

18/1

0.7660

0.6910

1.0043

1.0183

1.2630

1.2306

1.2360

1.2533

1.4541

1.4312

1.6223

1.6450

1.7940

1.7842

2.0085

2.0367

2.1496

2.1507

2.3948

2.4283

2.5143

2.5247

0.4635

0.4700

31.18

34.22

Grosbeak 636.0 26/7 0.8750 1.0725 1.3842 1.3200 1.5837 1.7325 1.9409 2.1450 2.3166 2.5575 2.7030 0.4950 29.50

Drake 795.0 26/7 1.0940 1.2003 1.6241 1.4773 1.8383 1.9390 2.2263 2.4007 2.6382 2.8623 3.0643 0.5540 26.86

Tern 795.0 45/7 0.8960 1.1516 1.4591 1.4173 1.6768 1.8603 2.0648 2.3032 2.4713 2.7461 2.8886 0.5315 30.68

6201 Aluminum Alloy Conductors

Azusa 123.3 7 0.1157 0.4312 0.4464 0.5307 0.5431 0.6965 0.7060 0.8623 0.8701 1.0282 1.0347 0.1990 59.83

Anaheim 155.4 7 0.1459 0.4843 0.5058 0.5960 0.6136 0.7823 0.7957 0.9685 0.9794 1.1548 1.1639 0.2235 56.86

Amherst 195.7 7 0.1857 0.5438 0.5740 0.6693 0.9641 0.8785 0.8975 1.0877 1.1031 1.2968 1.3098 0.2510 53.80

Alliance 246.9 7 0.2318 0.6099 0.6525 0.7507 0.7856 0.9853 1.0122 1.2198 1.2417 1.4544 1.4728 0.2815 50.53

Butte

Canton

312.8

394.5

19

19

0.2936

0.3703

0.6955

0.7811

0.7549

0.8644

0.8560

0.9613

0.9050

1.0302

1.1235

1.2618

1.1612

1.3150

1.3910

1.5622

1.4216

1.6055

1.6585

1.8626

1.6843

1.8990

0.3210

0.3605

47.55

44.23

Darien 559.5 19 0.5252 0.9295 1.0676 1.1440 1.2588 1.5015 1.5907 1.8590 1.9318 2.2165 2.2779 0.4290 39.24

Elgin 652.4 19 0.6124 1.0043 1.1762 1.2360 1.3794 1.6223 1.7340 2.0085 2.0998 2.3948 2.4718 0.4635 37.12

Flint 740.8 37 0.6754 1.0736 1.2684 1.3213 1.4839 1.7343 1.8611 2.1472 2.2509 2.5601 2.6477 0.4955 36.27

Greeley 927.2 37 0.8704 1.2003 1.4827 1.4773 1.7147 1.9390 2.1254 2.4007 2.5536 2.8623 2.9917 0.5540 32.48

Bulletin 1724E-153Page 28
Bulletin 1724E-153

Page 29

EXHIBIT C: CONTRIBUTORS

The following members of the Overhead Distribution Lines Subcommittee of the 

National Rural Electric Cooperative Association, Transmission and Distribution 

Engineering Committee provided invaluable assistance in preparing this document.

Byrne, James; Poudre Valley REA, Fort Collins, CO 

Glidewell, Allan; Southwest Tennessee EMC, Brownsville, TN

Gray, Weldon; Concho Valley Electric Cooperative, San Angelo, TX 

Hodge, Jon; Trinity Valley Cooperative, Athens, TX

Hoffman, Tom; Agralite Electric Cooperative, Benson, MN 

Lindsly, Gregory; Dixie EMC, Baton Rouge, LA

Nelson, Brian; Intercounty Electric Cooperative Assn., Licking, MO 

Rosenthal, Terry; Laclede Electric Cooperative, Lebanon, MO 

Smith, Gene; SGS Witter Inc., Lubbock, TX

Suggs, Thomas Jr.; Middle Tennessee EMC., Murfreesboro, TN 

Bohlk, James; Rural Utilities Service, U.S.D.A., Washington, D.C.