UNITED STATES DEPARTMENT OF AGRICULTURE 

Rural Utilities Service 

BULLETIN 1724E-204

RD-GD-2019-95

SUBJECT: Guide Specifications for Steel Single Pole and H-Frame Structures

TO: RUS Electric Borrowers, Consulting Engineers, and RUS Electric Program Staff 

EFFECTIVE DATE: Date of Approval 

OFFICE OF PRIMARY INTEREST: Engineering Standards Branch; Electric Program 

FILING INSTRUCTIONS: This bulletin replaces Bulletin 1724E-204, “Guide Specification 

for Steel Single Pole and H-Frame Structures” issued November 17, 2016. 

AVAILABILITY: This bulletin can be accessed via the Internet at: 

https://www.rd.usda.gov/publications/regulations-guidelines/bulletins/electric

PURPOSE: This bulletin provides guidance that should assist borrowers in procuring steel 

pole and steel H-frame structures. 

 April 9, 2019

Christopher A. McLean 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-204

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ACKNOWLEDGMENTS

The following current and former members of the Transmission Line Subcommittee of the 

National Rural Electric Cooperative Association, Transmission and Distribution Engineering 

Committee provided invaluable assistance in preparing this document:

Ballard, Dominic, East Kentucky Power Coop., Winchester, KY

Beadle, Bob, North Carolina EMC, Raleigh, NC

Beckett, Thomas, TL Beckett Consulting Engineers, Marietta, GA

Bertelsen, James, Dairyland Power Cooperative, La Crosse, WI

Caldwell, Art, Georgia Transmission Corporation, Tucker, GA

Harvey, Gary, East Kentucky Power Cooperative, Winchester, KY

Johnson, Wilson, USDA, Rural Utilities Service, Electric Program, Washington, DC

Kahanek, Bil, McCord Engineering, Inc., College Station, TX

Lukkarila, Charles, Great River Energy, Maple Grove, MN

McAndrew, Jeremy, South Mississippi Electric Power Assoc., Hattiesburg, MS

Metro, Patti, National Rural Electric Cooperative Association, Arlington, VA

Nordin, Bryan, Tri-State Generation & Transmission Association, Inc., Denver, CO

Ruggeri, Erik, Power Engineers, Hailey, ID

Shambrock, Aaron, South Central Power Company, Lancaster, OH

Twitty, John, PowerSouth Energy Cooperative, Andalusia, AL

Woodruff, Paul, Great River Energy, Maple Grove, MN

Zhang, Chendi, USDA, Rural Utilities Service, Electric Program, Washington, DC 
Bulletin 1724E-204

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TABLE OF CONTENTS

Instructions......................................................................................................................... vi–xiii

Technical Specifications .........................................................................................................1-24

1 Scope ..................................................................................................................................1

2 Definitions..........................................................................................................................1

3 Codes and Standards ..........................................................................................................2

4 Conflict between Specifications, Drawings, and Referenced Documents.........................2

5 General Requirements........................................................................................................2

6 Information to be Supplied by Manufacturers .................................................................13

7 Approval, Acceptance, and Ownership............................................................................14

8 List of Attachments to this Specifications........................................................................15

Attachment A - Structure Dimensions and Other Information ........................................16

Attachment B - Design Loads......................................................................................... 18

Attachment C - Application Requirements .................................................................... 20

Attachment D - Drawings................................................................................................ 22

Attachment E - Bid Summary-Design Information, Weights, and Costs 

(Information to be Submitted with Proposal) ........................................ 24

Appendix A - Commentary

Appendix B - Examples of Attachments A and B

Appendix C - Selected SI-Metric Conversions
Bulletin 1724E-204

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ABBREVIATIONS

ACI American Concrete Institute

ANCO American Nut Company 

ANSI American National Standards Institute

ASCE American Society of Civil Engineers 

ASTM American Society for Testing and Materials

AWS American Welding Society

DFT Dry Film Thickness

D/t Diameter of a circular section to plate thickness

Eq. F Equivalency Factor

ksi kips (1000 lb.) per square inch

kV kilovolt

mph miles per hour 

LF Load factor

NESC National Electrical Safety Code

NEMA National Electrical Manufacturers Association

SSPC Steel Structure Painting Council

OHGW Overhead ground wire

psf pounds per square foot

psi pounds per square inch

UNC Unified Coarse threads

DEFINITIONS

Borrower – An entity which borrows or seeks to borrow money from or arranges financing with 

the assistance of the Rural Utilities Service through guarantees, lien accommodations or lien 

subordinations.

Rural Utilities Service (RUS) – An Agency of the United States Department of Agriculture, 

under Rural Development.

RUS Electric Program Forms – All forms and bulletins referred to in this bulletin are Rural 

Utilities Service Electric Program forms and bulletins, unless otherwise noted.

Form 198 – Equipment Contract.

INDEX:

Poles: Steel

Materials and Equipment: Guide Specifications for Steel Pole Structures

Specifications and Standards: Guide Specifications for Steel Pole Structures

Transmission Facilities: Poles (Steel)
Bulletin 1724E-204

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INSTRUCTIONS

1. PURPOSE 

The intent of this guide specification is to provide Rural Utilities Service Electric 

Program borrowers with a basis for procuring adequate single pole and H-frame steel 

transmission line structures. Use of this specification should help eliminate ambiguities 

that might arise in the evaluation process of competitively bid steel pole procurements.

Borrowers or their engineering representatives will need to complete and add to this 

specification as appropriate. Modifications to this specification may be necessary to 

consider special applications or preferences of the owner.

2. SCOPE 

This suggested purchase specification covers the technical aspects of design, materials, 

welding, inspection, delivery, and protective coatings of single circuit steel pole and steel 

H-frame structures, 115 kV to 230 kV. This specification does not include contract 

(front-end) documents or specifications for construction. The user of this specification 

should add these documents, including general conditions and any supplemental 

instructions to the bidders. This specification may be expanded to include double circuit 

structures, and structures over 230 kV.

3. INITIAL DESIGN CONSIDERATIONS 

There are engineering decisions that should be made before completing the 

specifications. Some examples include:

• Amount of foundation rotation to consider for incorporating P-delta moments; 

• Location of point of fixity;

• Embedment depths;

• Load cases to be considered in addition to those required by the National 

Electrical Safety Code (NESC);

• Deflection limitations; and

• Guy wire modulus of elasticity

4. INFORMATION TO BE COMPLETED BY THE OWNER OR OWNER’S 

REPRESENTATIVE 

Users of this guide specification should detach the instructions and appendices and 

complete the following:

a. Documents and general information to be added to the specification: A number 

of front-end documents and general information need to be added to the 

specification:
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• Form 198 Equipment Contract(Recommended for competitive bidding)

• Supplemental Instructions to Bidders

• General Conditions

When there is competitive bidding, it is recommended that Form 198 be used. 

This form covers Notice and Instructions to Bidders, Proposal, and Equipment 

Contract. For item b above, Supplemental Information, the user may want to add 

such items as Bid Submission, Bid Price and Schedule, Bid Acceptance Period, 

Bid Requirements, and Bid Data. A section on General Conditions could include 

such items as Definition of Terms, Interpretation of Bid Documents, Addenda to 

the Bid Documents, Insurance, Method of Payment (if Form 198 is not used), 

Quantities, and Tabulation of Unit Prices.

b. Requirements to the technical specifications to be added or completed by the 

owner or owner’s representative and supplied to the bidders include:

(1) Configuration Requirements and Other Information (Attachment A of the 

Specification, or equivalent, to be added)

• Structure dimensions

• Conductor support locations

• Overhead ground wire (OHGW) support location(s)

• Underbuild support location(s)

• Guy attachment locations

• General load information

Transmission pole assemblies with steel Upswept arms on single Steel 

pole are named as TUS series. On the TUS-series single pole drawing on 

Pages xi, xii and xiii in these instructions, minimum acceptable 

dimensions are recommended. Specific project designs may require 

greater values than the minimum to improve insulator swing or galloping 

performance. The distance shown on the TUS-series drawing from the top 

phase conductor attachment point to the static wire attachment point 

provides for a 30 shielding angle. For further information on the 

lightning protection, see Bulletin 1724E-200 for details. For areas of high 

isokeraunic levels, high ground resistance, or high contamination, specify 

insulators with the number of bells detailed in the second column under 

each voltage level in Tables 1 and 2 of the TUS-series drawing in these 

instructions. Drawings TM-S1 and TM-S2 in these instructions suggest 

typical structure details.

Guide drawings for H-frame structures and double circuit structures have 

not been included in this bulletin.
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(2) Structural Requirements

(a) Design loads, with and without load factors (Attachment B of the 

Specification to be added)

Minimum loads should meet appropriate NESC District Loads, 

NESC extreme wind loads, NESC extreme ice with concurrent 

winds, any extreme ice conditions and local code loads with the 

appropriate load factors. 

All structures should have sufficient strength before conductor 

stringing to withstand the extreme wind velocity multiplied by an 

appropriate gust factor. The structures should be capable of 

withstanding this load from any direction. The vertical, 

transverse, and longitudinal loads with wind on the structure and 

the dead weight of the structure for any given condition should be 

applied simultaneously.

The loads without load factors for 60F, no wind, should be 

specified so that proper arm design and/or camber design can be 

made. Loads without load factors are required so that the 

manufacturer will supply appropriate base reactions with and 

without load factors (item 6.2.d) for foundation design purposes.

(b) Pole deflection limitations, if any, Attachment C of the 

Specification, to be completed. If deflection limitations are 

required, specify the loading condition(s) without load factors, and 

acceptable means of achieving (raking, cambering, stiffening).

(c) Desired foundation type (direct embedded or anchor bolt type), 

Attachment C of the Specification, to be completed. If embedded, 

the embedment lengths should be furnished. If anchor bolt type, 

strength of the concrete should be specified. The engineer has the 

option of specifying the maximum anticipated foundation rotation 

and groundline deflection in Attachment B. If different for 

individual loading cases, indicate quantities in the loading tables

(Attachment B). 

(d) Location, orientation, slope, type, size, strength of guys, 

(Attachment A of the Specification, to be added), and modulus of 

elasticity of guys, Attachment C of the Specification.

(3) Application Requirements (Attachment C of the Specification, to be 

completed).

(a) Special Charpy requirements.
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(b) Diameter and taper limitations, if any (flat-to-flat diameter for 

other than a round cross section).

(c) Desired method of surface protection. If a special corrosion 

problem exists, this should be mentioned, along with the 

recommended solution.

(d) Preference of climbing ladders, working ladders or step bolts. 

Also, quantity of removable ladders or step bolts to be supplied 

with the total order of poles should be specified.

(e) Component weight and/or length restrictions, if any.

(f) Delivery schedule and free on board (FOB) destination, and 

owners’ contact.

(g) Miscellaneous. (Additional items such as special attachment 

requirements, grounding requirements, climbing devices, hot line 

maintenance requirements.)

(h) Structures to be tested, if any, and number of load cases for each 

structure test.

(4) Structure drawing details (Attachment D of the Specification, to be added 

by owner). 

Drawings TUS series, TM-S1, and TM-S2 on pages xi, xii, and xiii of these 

instructions are provided as guidance drawings for development of 

Attachment D of the Specification.

5. INFORMATION TO BE COMPLETED BY THE MANUFACTURER

a. The owner or owner's representative should have the following information 

completed by the bidders and submitted with the manufacturer’s proposal. 

Attachment E of the Specification is a sample bid summary which includes this 

information.

(1) Calculated shipping weight of each structure, subassemblies, and 

components, excluding anchor bolts.

(2) Calculated shipping weight of anchor bolts.

(3) Maximum groundline reactions (moments, shears, and axial loads, 

including load factors) in poles and guy wires.

(4) Anchor bolt sizes, projections, lengths, layout and locations.

(5) Type of material and finish of major components, American Society of 

Testing and Materials (ASTM) number and grade.
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(6) Description of pole shaft, including thickness, length, diameter, crosssectional geometry, and method of fastening each shaft component.

(7) Method of attaching arms, braces, hardware, and miscellaneous 

appurtenances to structure.

(8) Design exceptions.

b. Documentation which the successful bidder needs to supply for approval by 

owner or owner's representative prior to manufacture include:

(1) Final design calculations for pole shaft, base plate, anchor bolts, arms, 

and other appurtenances, including their connections for all structures.

(2) The following specific items need to be supplied:

(a) For each loading case, the total shears and axial forces, moments, 

stresses, deflections, section moduli, cross-sectional area, safety 

factors (allowable stress/actual combined stresses); the w/t's for 

polygonal and D/t's for round cross sections at all attachment 

points, at top and bottom, and at least every ten (10) feet along the 

pole shall be supplied.

(b) Guy reactions for each loading case.

(c) For the critical loading case, shears and axial forces, moments, 

stresses, section modulus, cross-sectional area, and safety factor at 

the arm connections. Deflections at the end of the arm should also 

be given.

(d) Anticipated deflection at the top of the pole and at the end of the 

arms for each pole for the no wind load case at 60F without load 

factors.

(e) For all specified loading cases, all reactions and groundline 

moments with and without the load factors.

(f) Complete design/erection reproducible drawings for each 

structure type.

(g) Identification and weight of each structure - include the weight of 

components and a bill of materials for each structure.

(h) Assembly instructions.

c. Final documentation (as built) after construction. 

d. Test reports (as requested).
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TM-S1
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SPECIFICATIONS FOR 

STEEL SINGLE POLE AND H-FRAME STRUCTURES

1. SCOPE 

This specification covers the design, materials, welding, inspection, protective coatings, 

drawings and delivery of steel transmission single pole and H-frame structures. The 

proposal submitted by the manufacturer shall include field bolts, locknuts, vangs, 

attachment provisions for arms and/or insulators, anchor bolts, base plates, and other 

necessary items to make a complete structure.

2. DEFINITIONS

Camber - Pole curvature, induce in fabrication, used to counteract predetermined pole 

deflection, such that the pole will appear straight under a specified load condition.

D/t - the ratio of the diameter of a tubular pole to the steel plate thickness.

Engineer - a registered or licensed person, who may be a staff employee or an outside 

consultant, and who provides engineering services. Engineer also includes duly 

authorized assistants and representatives of the licensed person. 

Factored load - The maximum design load which includes the appropriate load factor

specified.

Groundline - a designated location on the pole where the surface of the ground will be 

after installation of a direct embedded pole.

Load factors (LF) - a multiplier which is applied to each of the vertical, transverse and 

longitudinal structure loads to obtain a factored load.

P-delta (P-∆) moment - secondary moment created by the vertical loads acting on the 

structure when the structure deflects from its unloaded position.

Point of fixity - location on the pole at groundline or below groundline where the 

maximum moment occurs. 

Pole twist - spiral rotation of a pole section relative to the pole end. It is caused by the 

residual stress in the steel as received from the mill, the clamping force holding the tube 

shells together and the heat applied during the seam welding process.

Raking - the practice of installing a straight pole out of plumb, or at an inclined angle

w/t - Ratio of the width of the pole (flat-to-flat) to the plate thickness

UNC – Unified Coarse Threads
Bulletin 1724E-204

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3. CODES AND STANDARDS

Codes, standards, or other documents referred to in this specification shall be considered 

as part of this specification. The following codes and standards are referenced:

a. American Society of Civil Engineers (ASCE) Standard, Design of Steel 

Transmission Pole Structures, ASCE 48, latest edition.

b. American Society for Testing and Materials (ASTM), various standards, latest 

revision.

c. American Concrete Institute (ACI), Building Code Requirements for Reinforced 

Concrete, ACI 318, latest edition.

d. American Welding Society (AWS), Structural Welding Code, AWS D1.1, latest 

edition.

e. American National Standards Institute (ANSI), National Electrical Safety Code, 

ANSI C2, latest edition.

f. Society for Protective Coatings (SSPC, formerly Steel Structure Painting Council)/ 

National Association of Corrosion Engineers (NACE) Surface Preparations 

Specification, SSPC/NACE SP-6/NACE 3. 

4. CONFLICT BETWEEN THIS SPECIFICATION, DRAWINGS, AND 

REFERENCED DOCUMENTS 

In the event of conflict between this specification and the above referenced documents, 

the requirements of this specification shall take precedence. In the case of conflict 

between several referenced documents, the more stringent requirement shall be followed. 

If a conflict exits between this specification or the referenced documents and the attached 

drawings, the attached drawings shall be followed. If clarification is necessary, contact 

the owner or owner's representative. 

5. GENERAL REQUIREMENTS 

The design, fabrication, allowable stresses, processes, tolerances, and inspection shall 

conform to the ASCE Standard, Design of Steel Transmission Pole Structures (ASCE 

48), latest edition, with the following additions and/or exceptions:

a. Design

(1) Pole designs shall be prepared from the attached configuration drawings 

(Attachments A and B of this Specification) and design loads (Attachment B 

of this Specification). The structure shall be capable of withstanding all
Bulletin 1724E-204

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specified loading cases including secondary stresses from foundation 

movements and pole deflection (P-∆) when specified in Attachment B of this 

Specification but not considering the possible restraining effect of conductors 

or shield wires. The structure shall withstand the loads without failure, 

permanent distortion, or exceeding any specified deflection limitations.

(2) Wind pressures shown in the loading criteria shall be multiplied by the 

appropriate shape factor applied to the poles. Pressures in psf shall be 

computed as follows:

 p = W x Cd

Where p = pressure on projected area of the pole normal to wind, W = wind 

pressure, and Cd = shape (or drag) factor.

Shape factors for computing the wind on poles are:

(3) The maximum design unit stress shall be the minimum yield strength as 

stated in applicable ASTM specifications for the particular application and 

types of loads, including load factors.

(4) Poles shall be designed with a minimum number of joints. Field welding 

shall not be allowed as part of the design of a new pole. The shaft joints to 

be made in the field shall be slip joints or bolted flange joints. Slip joint 

length shall be at least 1-1/2 times the largest inside diameter of the female 

section. Bolted flange joints shall be used for medium angle and heavy angle 

guyed structures and X-braced H-frame structures. If approved by the owner 

or owner’s representative, a strap across the pole splice to prevent separation 

of the male and female sections of the pole may be used for X-braced Hframe structures. Approval must be obtained prior to bid.

Manufacturer shall verify slip joint fit before shipment. Joints should not 

interfere with joints, step nuts, ladder clips, or jacking nuts.

Sufficient jacking lugs and permanent orientation marks shall be provided at 

all slip joints to ensure proper alignment and complete overlap of the joint.

(5) The factored load in guys shall not exceed 65 percent of the rated breaking 

strength of the guy.
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(6) Design of anchor bolts shall be in accordance with the ACI-318, latest

Edition, Building Code Requirements for Reinforced Concrete, assuming a 

concrete strength as specified by the owner.

When anchor bolts are specified, they shall have the top 2 feet galvanized. 

Anchor bolts shall be threaded at the top end a distance equal to the baseplate 

thickness plus the thickness of two anchor bolt nuts plus 2-1/2”. Each anchor 

bolt shall include two heavy hex nuts.

Welding on anchor bolts will only be allowed in the bottom 12 inches. Only 

one length of anchor bolt shall be used on each pole. Anchor bolts/clusters 

shall be plainly marked to indicate the structure type, structure number, 

orientation, and top of concrete. 

Anchor bolts shall be designed to be shipped as a rigid cage with top and 

bottom plates holding the anchor bolts in place. The anchor bolt thread shall 

be protected during shipping. The anchor bolts shall be welded to the 

holding plate in the bottom of the cage. The top template shall be designed 

to be removable and to support the assembled cage during lifting and setting 

operations without detrimental deformations. Bolt clusters shall be designed 

to be rigid enough to withstand the normal jolts of shipping, handling and 

installation with no displacement of bolts from the proper positions within 

the cluster.

The removable template at the top shall be marked to show the centerline for 

tangent structures and the angle bisector for angle structures. Matching 

marks are to be on the base plate of the structure so proper alignment can be 

made.

(7) Minimum plate thickness for all pole components shall be 3/16 inch.

(8) Structures which are to be direct embedded shall have bearing plates and 

ground sleeves. Bearing plates shall have a diameter not more than 2 inches 

greater than the maximum pole diameter. 

Galvanized poles shall have a drain hole at the bottom. The drain hole shall 

not be more than 20% of the bottom plate surface area. When a painted finish 

is specified, poles shall be hermetically sealed. Ground sleeves shall have a 

minimum length of 3 feet for single pole structures and 4 feet for H-frames.

The ground sleeve shall have a minimum thickness of 3/16 inch and shall be 

centered at the groundline. A seal weld shall be provided around the ground 

sleeve. The ground sleeve shall not be considered in strength calculations.
Bulletin 1724E-204

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(9) Poles shall have nearly a uniform taper throughout their entire length. The 

maximum difference in tapers between two pole sections measured by the 

diameters shall be .20 inch/ft. for poles with variable taper.

(10) Poles with elliptical cross sections shall have a minor axis dimension equal to 

at least 75 percent of the major axis dimension.

(11) All unguyed angle poles or unguyed tangent deadends shall be precambered 

to remain plumb when the calculated deflection at the top of the pole exceeds 

1.5 percent of the pole height under an initial conductor tension loading of 

60°F, no wind, and no load factors. Pole height shall be the height of the 

pole from the top of the baseplate, or designated groundline, to the top. 

Tangent poles with unbalanced vertical loadings shall be precambered for the 

previously stated conditions.

(12) Arms shall be designed so the end of the arm is at the specified height under 

a loading of initial conductor tension, 60°F, no wind, and no-load factors. 

Arms shall not deflect vertically more than 12 inches at the end of the arm 

under heavy ice conditions (without any load factors applied).

Arms shall be upswept or straight, tapered, steel tubular members, of any 

cross-sectional type, which meet the dimensions shown on the attached 

drawings (Attachment D of this Specification).

Arm end plate connection details for hardware attachment shall be typical of 

those shown on the attached drawings. The arms shall be hermetically sealed 

when a painted finish is specified. Galvanized arms shall have drain holes 

where appropriate. If weathering steel is used for the arms, attachments and 

the arm shall be designed to avoid trapping or holding moisture.

(13) Lifting lugs are optional. The manufacturer shall supply all instructions for 

handling and erection of poles and arms.

(14) In the design of connections for vangs, brackets, or stiffeners attached to the 

pole shaft, care shall be taken to distribute the loads sufficiently to protect the 

wall of the pole from local buckling.

(15) Each pole shall be permanently marked on the pole shaft 60 inches above 

groundline and on the bottom of baseplate or bearing plate with the following 

identifying information: structure type, height, structure number, factored

groundline moment, owner name, and date manufactured. The method of 

identification shall be approved by the owner.

(16) Weathering steel structures shall be designed to eliminate water and refuse 

traps.
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Tubular sections shall be sealed from moisture entering the inside of the pole. 

Factory drilled pole holes shall be plugged to prevent moisture intrusion 

during shipping. For field drilled poles and factory drilled poles, 

manufacturer shall provide silicon sealant to seal all through-bolt holes. 

Nondrilled poles when assembled shall be effectively sealed to prevent 

moisture intrusion. 

Connections shall be designed to reduce the effect of pack-out by preventing 

moisture from entering the joint or by designing the connection to allow 

moisture to easily drain off.

Plastic plugs shall be installed in all nuts welded to the structure and all 

tapped holes.

(17) Application requirements: (See Attachment C of this Specification)

b. Materials

(1) All materials shall comply with the applicable requirements of ASTM 

specifications. Any modifications to ASTM specifications must be approved 

by the owner's representative prior to bidding.

(2) Poles, arms and conductor brackets shall conform with ASTM A36, ASTM 

A572, ASTM A588, ASTM A871 or ASTM A595.

(3) Base plate shall conform with ASTM A572, ASTM A588, ASTM A633, or 

ASTM A595.

(4) Anchor bolts shall conform to ASTM A615, Grade 60 or 75.

(5) Other bolts and nuts shall conform, as applicable, to ASTM A307, ASTM 

A325, ASTM A354, or ASTM A394. Locknuts shall be provided for each 

structure bolt, or American Nut Company (ANCO) type self-locking nuts 

may be used. Locknuts shall be the galvanized MF type or ANCO type.

(6) Anchor bolts, structural plate, and weld material shall meet ASCE 

requirements for Charpy tests.

(7) For galvanized structures, steel used for the pole shaft and arms shall have a 

silicon content less than .06 percent.

c. Fabrication

(1) All welding shall be in accordance with the AWS D1.1, latest edition. 

Welders shall be qualified in accordance with AWS D1.1 welding 

procedures.
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(2) One hundred percent penetration welds shall be required in, but not limited 

to, the following areas:

• circumferential welds (C-welds) joining structural members;

• longitudinal welds in the female portion of the joint

within the slip joint area;

• welds at the butt joints of back-up strips; and

• base plate to shaft weld.

• longitudinal welds within 3 inches of C-welds, flange welds, base 

welds and ends of tubes.

(3) Full penetration or equivalent 90 percent partial penetration with fillet 

overlay shall be used for arm-to-arm base, vang-to-plate shaft, and arm box 

joints.

(4) Quality and acceptability of every inch of the full penetration welds shall be 

determined by visual and ultrasonic inspection.

(5) All other penetration welds shall have 60 percent minimum penetration. 

Quality and acceptability of all welds other than full penetration welds shall 

be determined by visual inspection, supplemented by magnetic particle, 

ultrasonic or dye penetrant inspection.

(6) All weld back-up strips shall be continuous the full length of the welds. Care 

shall be exercised in the design of welded connections to avoid areas of high 

stress concentration which could be subject to fatigue or brittle fractures.

(7) Field welding shall not be permitted except with owner’s approval and the 

manufacturer’s direction in repairing a pole.

(8) All parts of the structure shall be neatly finished and free from kinks or 

twists. All holes, blocks, and clips shall be made with sharp tools and shall 

be clean-cut without torn or ragged edges.

(9) Before being laid out or worked in any manner, structural material shall be 

straight and clean. If straightening is necessary, it shall be done by methods 

that will not damage the metal.

(10) Shearing and cutting shall be performed carefully and all portions of the 

work shall be finished neatly. Copes and re-entrant cuts shall be filleted 

before cutting.
Bulletin 1724E-204

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(11) All forming or bending during fabrication shall be done by methods that will 

prevent embrittlement or loss of strength in the material being worked.

(12) Holes for connection bolts shall be 1/16 inch larger than the nominal 

diameter of the bolts. Holes in the flange plates for bolted splices shall be 

1/8 inch larger than the bolt diameter. Holes in the base plates for anchor 

bolts shall be 3/8 inch larger than the nominal diameter of the anchor bolts. 

The details of all connections and splices shall be subject to the approval of 

the owner or his representatives.

(13) Holes in steel plates which are punched must be smooth and cylindrical 

without excessive tear out or depressions. Any burrs that remain after 

punching shall be removed by grinding, reaming, etc.

(14) Holes of any diameter may be drilled in plate of any thickness. Care shall be 

taken to maintain accuracy when drilling stacks of plates.

(15) Holes may be made by use of a machine guided oxygen torch. Flame cut 

edges shall be reasonably smooth and suitable for the stresses transmitted to 

them.

(16) Field drilled holes must be approved by the owner. If the manufacturer is 

aware of the owner's intent to field drill holes, the manufacture must supply a 

galvanizing touch-up kit for galvanized poles or a silicon sealant for 

weathering steel poles. 

d. Tolerances

Manufacturing tolerances shall be limited to the following:

Pole Length One piece: ±2 inches, or ±1 inch ±1/8 inch per 10 feet of length, 

whichever is greater (i.e. - 120 foot pole shall have a length of 120 

feet ±21⁄2 inches)

Assembled pole with flange connections: same as for one piece

Assembled pole with slip joint connections: The accumulation of the 

slip joint tolerances not to exceed –6”, +12”

Pole Diameter -0 inch, +1/4 inch

Pole End Squareness ±1/2 inch per foot of pole diameter

Pole Sweep 1/8 inch per 10 feet of pole length

Pole Twist

Limit twist to 1°/10' of length, not to exceed 4°/tube segment. Overall 

structure twist shall be limited to 10° for embedded and 6° for base 

plated structures. Connections for all appurtenances to the pole shall 

account for the pole twist and should align vertically.

Slip Joint tolerances Tolerances per manufacturer’s recommendations and total pole 

length requirements above.
Bulletin 1724E-204

Page 9

Location of Groups 

of Bolt Holes from 

Top of Pole

±1.0 inches (tolerance to 

dimension ‘A’, Figure 2)

Location of 

Centerline Between 

Groups of Bolt Holes 

±1.0 inch (tolerance to 

dimension ‘B’, Figure 2)

Location of Holes 

Within a Group of 

Bolt Holes

±1/8 inch (tolerance to 

dimension ‘C’, Figure 2)

Bolt Hole Alignment Not to vary from the longitudinal pole centerline of that group of 

holes by more than 1/16 inch

Location of 

Identification Plate

±2.0 inch

e. Grounding

(1) A grounding connection shall be welded to the pole shaft, 18 inches above the 

groundline or 6 inches above the ground collar. The grounding connection 

will be either the two-hole NEMA pad, or a nut, or a threaded insert installed 

in the pole, or an approved alternative. 

(2) Grounding pad face shall not be painted or covered with other coatings. The 

grounding nut thread and grounding pad threads shall be protected from 

coatings.

(3) Threaded inserts installed for grounding shall be made of Type 316 stainless 

steel and provided with standard 1⁄2 inch, 13 UNC threads. Threads shall be 

protected from coatings.

f. Climbing Devices

(1) Design Loads

(a) Step Bolts and removable steps: The step bolts, removable steps and 

attachment to the pole shall be designed to support a minimum of a 

300-pound worker and equipment multiplied by a load factor as 

FIGURE 2

A

B

C

C POLE L
Bulletin 1724E-204

Page 10

defined in paragraph 5.f.(2). The load shall be at the outer edge of the 

step or bolt.

(b) Removable Ladders: The ladder and each attachment to the pole shall 

be designed to support a minimum of a 300-pound worker and 

equipment multiplied by a load factor as defined in paragraph 5.f.(2). 

The load shall be at the outer edge of the step or bolt. 

(2) Load Factor

A load factor of 2.0 shall be applied to the design loads in 5.6.1. These loads

shall be supported without permanent deformation. 

(3) Location

Climbing devices shall start 8 feet above groundline and extend to the pole top 

unless specified by the owner. The climbing device shall be spaced such that 

each step is 1 foot 6 inches apart and orientated to provide maximum ease of 

climbing. They shall be located to avoid interference with other attachments

g. Finishes

(1) The following finishes are acceptable: galvanizing, zinc primer and painting, 

weathering steel, and below grade coating.

(a) Galvanizing - All structures and structural components which are hotdip galvanized shall meet all the requirements of ASTM A123 or 

ASTM A153. Measures shall be taken to prevent warping and 

distortion according to ASTM A384 and to prevent embrittlement 

according ASTM A143. Poles made of ASTM A588 steel shall not be 

galvanized due to the high silicon content of the steel. One gallon of 

zinc enriched paint shall be provided with each five poles.

(b) Zinc Primer and Painting - Poles which are to be painted shall be 

hermetically sealed to prevent corrosion of interior surfaces. After 

shot or sand blasting and cleaning in accordance with the surface 

preparations specification, SSPC/NACE SP-6/NACE 3, a zinc primer 

of 3 mils dry film thickness (DFT) and two coats of finish paint, each 

3 mils DFT shall be applied to all exterior surfaces in accordance with 

the paint supplier's recommendations. One gallon each of primer and 

finish paint shall be supplied with each five poles. A guarantee against 

flaking or fading of the paint for a minimum of 5 years shall be 

provided. 

(c) Weathering Steel - Steel shall conform to ASTM A588 or A871. After 

fabrication, poles made of weathering steel shall be cleaned of oil, 
Bulletin 1724E-204

Page 11

scale, etc., in accordance with the surface preparation specification 

SSPC/NACE SP-6/NACE 3, to ensure uniform and rapid formation of 

the protective oxide layer. 

(d) Coatings for the Embedded Portion of the Pole - When poles are to be 

directly embedded, a 16 mil (minimum dry film thickness), two 

component hydrocarbon extended polyurethane coating that is 

resistant to ultraviolet light shall be applied on the exposed surface of 

the embedded portion of the pole. The coating shall extend from the 

butt to the top of the ground sleeve. Other coatings shall be approved 

by the owner prior to their use. 

(2) Bolts and nuts with yield strengths under 100,000 psi shall be hot-dip 

galvanized per ASTM A153 and ASTM A143, or mechanically coated with 

zinc in accordance with ASTM B454, Class 50. Bolting materials with yield 

strengths in excess of 100,000 psi shall not be hot-dip galvanized. Instead, 

they shall be painted with zinc enriched paint or mechanically coated with 

zinc per ASTM B454, Class 50.

(3) Compliance with coating thickness requirements shall be checked with a 

magnetic thickness gauge.

h. Inspection and Testing

(1) The owner and the owner’s designated agents shall have free entry at all 

times while work is being carried on, to all parts of the manufacturer's plant 

to inspect any part of the production of the poles covered by this 

specification.

(2) Steel members which are bent or warped or otherwise improperly fabricated 

shall be properly repaired or replaced.

(3) The cost of tests made by the manufacturer (except full scale load tests on 

poles), including cost of the certified test reports shall be considered included 

in the price.

(4) The manufacturer shall make tests in accordance with 

ASTM A370 and ASTM A673 to verify that the material used in the 

structures meets the impact properties.

(5) Mill test reports showing chemical and physical properties of all material 

furnished under this specification shall be maintained by the manufacturer for 

a period of 5 years and shall be traceable to the structure.

(6) All plates over 1-1/2 inches thick shall be ultrasonically tested to assure 

against defects which could lead to lamellar tearing.
Bulletin 1724E-204

Page 12

(7) Welders or welding operators shall be qualified in accordance with the 

provisions of AWS D1.1.

(8) The manufacturer shall make certified welding reports for each structure. 

The reports covering welding shall include all welds of each structure. Each 

weld shall be clearly identified; and the report shall consist of the method of 

testing, whether the weld is acceptable, the identification of the structure, the 

date, and the name and signature of the inspector.

i. Structure Testing

(1) The structures which are to have full-scale load tests performed on them are 

listed in Attachment C of this Specification.

(2) Details of the test procedures and methods of measuring and recording test 

loads and deflections shall be specified by the manufacturer prior to testing 

and shall be subject to the review and approval of the owner or his 

representative.

(3) Deflections shall be recorded in the transverse and longitudinal directions 

when applicable. Deflection measurements shall be taken under the no load 

condition both before and after testing.

(4) Material procurement for test poles shall be identical to material procurement 

procedures for regular production run poles.

(5) A full report listing results shall be submitted after completion of all testing. 

Copies of mill test reports shall be included in the load test report. The report 

shall also include a complete description of the load tests with diagrams and 

photographs.

(6) The owner or his representative reserves the right to be present during testing 

and shall be notified 2 weeks prior to the start of structure fabrication.

j. Shipping

(1) Each shipment shall be accompanied by a list of all parts, identifiable by 

structure type and number. Arms, bolts and miscellaneous hardware will be 

identified by the list for match up with the respective pole shaft. All parts 

required for any one structure shall be in one shipment, if possible.

(2) The owner and owner's representative shall be notified prior to shipment that 

such shipment is to take place, and they reserve the right to inspect the 

components prior to shipment. The notification shall give quantities, weight, 

name of common carrier used, and expected time of arrival.
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Page 13

(3) The anchor bolts shall be welded to the holding plate in the bottom of the 

cage. A removable template shall be used at the top of the cage and shall be 

marked to show the centerline for tangent structures and the angle bisector 

for angle structures. Matching marks are to be on the base plate so proper 

alignment can be made. Bolt clusters shall be rigid enough to withstand the 

normal jolts of shipping and handling with no displacement of bolts from the 

proper positions within the cluster.

(4) Unless otherwise agreed to by the owner, the anchor bolt cage shall be 

shipped at least 30 days prior to pole shipment. 

(5) Salt-treated wood blocking and urethane foams shall not be used when 

shipping or storing steel poles.

6. INFORMATION TO BE SUPPLIED BY THE MANUFACTURER

a. Information to be supplied with the proposal (Attachment E of this Specification).

(1) Calculated shipping weight of each structure excluding anchor bolts. 

Separate weights shall be given for arms and poles.

(2) Calculated shipping weight of anchor bolts.

(3) Factored groundline reactions in poles and guy wires.

(4) Anchor bolt size, length and locations (bolt circle diameters).

(5) Type of material of major components (ASTM number).

(6) Description of pole shaft, including thickness, length, diameter, crosssectional geometry, and method of fastening each shaft component.

(7) Data showing the design of the arm, arm connections, arm attachment plates 

and brackets.

(8) Sketches or draft drawings of structure and structure attachments.

b. Documentation to be supplied for the owner’s approval prior to fabrication

Documentation includes final design calculations for pole shaft, base plate, anchor 

bolts, arms, and other appurtenances, including their connections for all structures. 

The following information shall be supplied:
Bulletin 1724E-204

Page 14

(1) For the loading cases with load factors, the total shear, axial forces, 

moments, stresses or stress ratios, section moduli, cross-sectional areas, 

deflections w/t's for polygonal and D/t's for round cross sections at all 

splices, at arm attachment points (top and bottom), and at least every 10 feet 

along the pole.

(2) For the critical loading case, shear and axial forces, moments, stresses,

section moduli, cross-sectional areas at the arm connections, bolt stresses in 

the arm connection, and deflection at the end of the arm.

(3) Anticipated deflections at the top of the pole and at the ends of the arms shall 

be indicated for each pole for the normal, everyday loading condition of 

60°F, no wind, no load factors.

(4) For all specified loading cases, reactions and groundline moments shall be 

supplied.

(5) Detail drawings for each structure type giving weights of structure 

components, dimensions, and bill of materials.

(6) Assembly instructions and erection drawings. Slip joint lengths and 

allowable tolerances. Special handling instructions.

c. Final Documents shall be supplied to the owner for the items in Section 6.b.(5), 

after erection of all structures and prior to final payment.

d. Test Reports (as requested).

(1) Certified mill test reports for all structural material.

(2) Certified welding reports for each structure.

(3) Impact property test reports showing that the material used in the structures 

meets the impact properties.

(4) Test reports on coating thickness.

(5) Report of structure testing, when required, including photographs, diagrams, 

load trees, etc.

7. APPROVAL, ACCEPTANCE, AND OWNERSHIP

a. Final designs must be approved by the owner or owner's representative before 

material ordering and fabrication. Material ordering and fabrication prior to 

approval will be at supplier's risk. It is understood that award of this contract does 

not constitute acceptance of design calculations submitted with the bid, if 

corrections are required in the final structure designs due to manufacturer's errors, 

omissions, or misinterpretations of the specifications, the quoted price shall not 

change. Approval of the drawings and calculations by the owner or the owner’s 

representative does not relieve the supplier of responsibility for the adequacy of the 
Bulletin 1724E-204

Page 15

design, correctness of dimensions, details on the drawings, and the proper fit of 

parts.

b. After delivery, the poles will be inspected and shall be free of dirt, oil blisters, flux, 

black spots, dross, tear-drop edges, flaking paint or zinc; and in general, shall be 

smooth, attractive, and unscarred. Poles not meeting this requirement shall be 

repaired or replaced by the fabricator at no additional cost to the owner.

c. All final drawings shall become the property of the owner, who shall have full 

rights to reproduce drawings and use them as the owner sees fit, including 

submitting them to other vendors for the purpose of obtaining bids on future steel 

pole purchases.

8. LIST OF ATTACHMENTS TO THIS SPECIFICATION

• Attachment A, Structure Dimensions and Other Information (to be completed by 

the engineer)

• Attachment B, Design Loads (to be completed by the engineer)

• Attachment C, Application Requirements (to be completed by the engineer)

• Attachment D, Drawings (to be completed by the engineer)

• Attachment E, Bid Summary-Design Information, Weights, and Costs

(to be completed by the manufacturer and submitted with proposal)
Bulletin 1724E-204

Page 16

Attachment A. Structure Dimensions and Other Information (To be completed by engineer)
Bulletin 1724E-204

Page 17

BLANK PAGE
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Page 18

Attachment B. Design Loads (To be completed by engineer)
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BLANK PAGE
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Page 20

Attachment C. Application Requirements

1. Pole deflection limitations

a. Means of achieving.......................... ____________

b. Amount of....................................... ____________

c. Loading conditions for..................... ____________

2. Foundation type.......................................... ____________

a. Design concrete compressive strength (psi)..__________

b. Maximum anticipated foundation rotation 

 measured from the vertical axis(degrees)

 and maximum anticipated deflection at the

 groundline (inches)......................... ____________

3. Special Charpy requirements..................... ____________

4. Maximum diameter (flat-to-flat) at 

groundline (inches)..................a. Tangent: ____________

 b. Angle: ____________

 c. Deadend: ____________

5. Maximum taper (inches/foot) based on total

 difference between top and bottom diameters. ____________

6. Guy wire modulus of elasticity.................. ____________

7. a. Surface protection desired.................. ____________

 b. If painted, color desire.................... ____________

8. a. Climbing device desired..................... ____________

 b. Quantity of removable ladders or step bolts. ____________

9. Unguyed angle poles to be raked or

 precambered..................................... ____________

10. Unguyed tangent deadends to be raked 

or precambered.................................. ____________

11. Grounding plate or nut.......................... ____________
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Page 21

Attachment C. Application Requirements

(Cont’d)

12. Component weight restrictions................... ____________

13. Pole length restrictions........................ ____________

14. Delivery schedule............................... ____________

15. Free on board destination....................... ____________

16. Structures to be tested:

Structure Type Load Cases to be Tested

a.

b.

c.

17. Miscellaneous
Bulletin 1724E-204

Page 22

Attachment D. Drawings (To be added by owner)
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BLANK PAGE
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Page 24

Attachment E. Bid Summary-Design Information, Weights, and Costs

(To be completed by the manufacturer and submitted with proposal)

Attachment E

(See Hard Copy for Attachment E, 

Bid Summary-Design, Weights , and Costs )
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Page 25

BLANK PAGE

Bulletin 1724E-204

Appendix A

Page 1

APPENDIX A

COMMENTARY
Bulletin 1724E-204

Appendix A

Page 2

APPENDIX A

COMMENTARY ON GUIDE SPECIFICATIONS

FOR STEEL POLE STRUCTURES

1. General

The necessity of a clear bid specification for the purchase of steel poles is very important 

to the bid evaluation process and the acquisition of structurally adequate poles. The 

specification should contain sufficient requirements and information so that all bids can 

be evaluated equally and so that the fabricator clearly understands what is expected.

The basis of the technical specification is the American Society of Civil Engineers 

(ASCE) standard on Design of Steel Transmission Pole Structures, with additions and/or 

exceptions made to the specification. There are several items in the specification which 

need further explanation. The section references in the commentary refer to the section 

in the Specifications.

2. Section 5.a - Design Requirements

Loads - Section 5.a. (1)

The primary loads for transmission pole structures are weather loads and erection loads. 

Erection loads in the handling of the steel poles are determined by the manufacturer and 

included in the manufacturer’s design. Erection loads incurred in the construction of the 

line should be determined by the owner and specified in the loading trees. Weather loads 

must be clearly specified by the owner. The location and direction of loads should be 

indicated in a loading agenda or loading trees, and should have units of Newton’s, 

pounds, or kips (or for uniform wind loads on the structure, Pascal’s, lb./ft.

2, or kips/ft.2). 

The specifying of loads in the form of general environmental criteria such as wind 

velocity or radial thickness of ice, is insufficient. Not only is there difficulty in 

evaluating bids, but there also is a greater possibility of error in calculated design loads.

ASCE Publication on the Guidelines for Electrical Transmission Line Structural 

Loadings, (Manual 74), describes different load conditions. Load factors for NESC light, 

medium, and heavy loading districts should be at least equal to those given in the latest 

edition of NESC for Grade B construction. Load factors for extreme ice and extreme 

wind should be at least 1.1. The load factors suggested for extreme conditions are made 

with the idea that testing of the structure will be to the calculated loads with a load factor 

of 1.0. Extreme wind loads for recurrence intervals greater than 50 years should also be 

considered. An appropriate gust factor should be applied to the wind velocity when 

considering wind on the structure. Arms should be able to sustain a minimum working 

load of 500 pounds for a lineman in addition to conductor and insulator design loads.
Bulletin 1724E-204

Appendix A

Page 3

The normal load for 60F no wind should be given as one of the loading cases so that 

davit arms and/or camber of a pole can be properly designed.

P-delta (P-) Moments

The specification requires the fabricator to include in its analysis the secondary moment 

due to the unbalanced vertical load. Whenever there is a transverse or longitudinal load, 

the pole will deflect in the direction of the load. As a result, the vertical loads are no 

longer in its original position. The vertical loads have moved over as the pole deflects, 

causing additional moments (sometimes called P- moments). This specification 

requires this deflection related moment to be included in the analysis. The deflection and 

resulting P- moment should be calculated for the loads (including load factors) indicated 

in the loading agenda.

Foundation Rotation and Deflection

This specification allows the user the option of specifying a foundation rotation, either as 

a maximum for all load cases or as a certain amount for each load case. For purposes of 

bidding and design, the owner or owner’s engineer also has the option to simply specify a 

fixed base with no foundation rotation or deflection.

When specifying the maximum value for the foundation rotation and deflection for all 

load cases, the engineer establishes performance requirements for the steel pole and 

foundation. In determining this value, aesthetics, phase-to-structure clearances, phase-toground clearances, or even the ability to replumb a structure should be considered.

The specifying of a rotation and deflection for each load case is a refinement in analysis 

and design which allows the user to match types and probability of loads with foundation 

response. For instance, under a 50-year extreme wind load, one may allow more 

foundation deflection and rotation than under NESC heavy loading district loads.

In the case where foundation rotation-deflection is specified, the manufacturer should 

include such effects in calculations of final deflected pole stresses (P- effects). The 

rotation and deflections when specified should be for the respective loads with load 

factors.

Longitudinal Loads

Because steel poles are flexible structures, there may be a reduction in induced moments 

in a pole under some types of longitudinal loads due to the restraining effect of the 

overhead ground wires. Traditionally, static longitudinal loads are specified due to the 

complexity of calculating the influence of structure flexibility. Reducing these loads 

because of the restraining effects of the static wires presents certain difficulties in bid 

evaluation.
Bulletin 1724E-204

Appendix A

Page 4

In order to be certain that steel pole bids can be evaluated on an equal basis, this 

specification requires that all longitudinal loads specified in the loading agenda are not to 

be reduced due to flexibility of the structure. If the owner wishes to take advantage of 

structure flexibility, then the owner's engineer should estimate structure and line 

parameters. The “reduced” longitudinal design loads should then be specified on the 

loading trees.

This approach is better than having the steel pole manufacturers account for structure 

flexibility since: (1) not all manufacturers have the capability to perform such an 

analysis, (2) the owner or owner’s engineer will have to evaluate the manufacturer's 

design anyway, and (3) plan and profile drawings would have to be included in the 

contract documents so that proper evaluation of the effect of longitudinal loads between 

deadends can be made.

Shape Factors - Section 5.a.(2)

Shape factors (drag coefficients) have been established for various pole cross sections so 

that manufacturers will be designing on the same basis. These drag coefficients are a 

function of wind velocity, diameter, and shape of the member. If the user modifies this 

section of the specification in order to reflect more refined drag coefficients, the user 

should be certain to provide all additional information needed to clearly and precisely 

define the loads.

Guy Wires - Section 5.a.(5)

Any time a steel pole structure is guyed, the guy type, size, modulus of elasticity and guy 

slope or angle must be specified by the owner. The manufacturer needs this information 

to properly analyze the structure. This specification limits the load in the guy to 

65 percent of its ASTM rated breaking strength. The manufacturer should design the 

pole and guy wire(s) as a system. The manufacturer may wish to reduce pole capacity by 

using a larger than specified guy wire size. This action should be avoided unless the 

owner approves the use of a larger guy size, and subsequent anchor changes. 

In design, the loads with the respective load factors are applied at appropriate locations 

on the guyed structure. 

The guy modulus of elasticity can increase from a minimum value at the time of 

manufacture, to a maximum value which results from periodic stretching and relaxing 

during the load cycles. Ranges from 19,000 ksi to 28,000 ksi have been stated. The 

ASCE 48 Design of Steel Transmission Pole Structures has suggested a guy wire 

modulus of elasticity of 23,000 ksi be used by the pole designer whenever it is not 

specified.
Bulletin 1724E-204

Appendix A

Page 5

Ratio of Minor to Major Axis - Section 5.a.(10)

Longitudinal loads are sometimes difficult to determine. In order to reduce the chances 

of a cascading failure in a tangent structure, this specification requires the minor axis of 

an elliptical or rectangular section to be not less than 75 percent of the major axis. This 

requirement will provide inherent longitudinal strength for steel pole tangent structures. 

In most instances, this inherent longitudinal strength is naturally provided in the design 

process.

Wind Induced Vibrations

Members of all types of transmission structures may occasionally be subject to wind 

induced vibrations.

The manufacturer should detail each structure using good design practices considering 

this possibility. If vibrations are experienced, the owner should add additional damping 

to the structure. Damping may be particularly important on structures which are to be 

installed without conductors for an extended period of time.

Direct Embedded Steel Poles - Section 5.a.(8) 

There may be problems associated with requiring a base/bearing plate for direct 

embedded poles where soil conditions require the use of driller’s mud during the 

augering process. When installing the pole, the pole may float and it is impossible to set 

it in the foundation unless the water is removed from the hole, which may cause the sides 

of the hole to collapse. Specifying galvanized poles with a 6 to 12-inch diameter hole in 

the base plate may be necessary. Once crushed rock is placed in the bottom of the hole, 

the pole lowered, the drillers mud and water can be pumped out of the hole as the pole is 

set. The remaining water in the pole will drain out of the bottom of the pole through the 

crushed rock. If weathering steel poles are used and a hole is placed in the bearing plate, 

the embedded portion of the pole should be coated inside and outside.

Use of direct embedded steel poles should be evaluated for the first two spans outside of 

a substation or generating plant. The large amount of copper used in a substation 

grounding grid may create a galvanic corrosion cell, with the steel of the pole sacrificing 

itself. Anodes or extra subsurface protection may be needed.

3. Section 5.b - Materials

Charpy Requirements - Section 5.b.(6)

A Charpy test is a notch-bar impact test used to compare notch sensitivities of materials. 

The impact values cannot be converted into energy figures for use directly in engineering 

design. The impact value from the notch-bar impact test is used only as a comparison 

test. For example, if a type of steel has been found to have a good notch toughness in
Bulletin 1724E-204

Appendix A

Page 6

service and its impact value is known, it is assumed that other types of steel having the 

same impact value will also have the same notch toughness. The ASCE design standard 

for steel poles has established impact values for the Charpy notch-bar impact test. These 

values are a function of yield stress, plate or bar thickness, and temperature.

Notch-bar impact tests are used to help determine if a normally ductile material might 

behave in a brittle manner. Three main factors which influence if a material will behave 

in a brittle or ductile manner are triaxiality, strain rate, and temperature. Ductile 

materials tend to become more brittle as triaxiality increases, strain rate increases, or 

temperature decreases. Since brittle materials require far less energy for fracture than 

ductile materials of the same strength, one can realize the importance of the Charpy test 

for steel poles used on transmission lines.

The tendency is to reduce temperature requirements of the Charpy test for structures to be 

in service in warm climates such as Louisiana or Florida. This is not recommended. 

However, for locations in which temperatures may be extremely low, lower temperature 

values may need to be specified.

The ASCE design standard specification contains Charpy requirements for structural 

plate, anchor bolts, and weld materials. The material used for making welds is required 

to meet the impact requirements for the lowest toughness requirements of the plates being 

joined.

4. Section 5.c - Fabrication (no comments)

5. Section 5.d - Finishes

Weathering Steel

There are environments where weathering steel is not recommended in a bare, uncoated 

condition because the protective, tight oxide will not form properly. These environments 

include: (1) atmospheres containing concentrated corrosive industrial fumes, (2) marine 

locations subject to salt-water spray or salt-laden fogs, or (3) applications where the steel 

may be continuously submerged in water (salt or fresh)or buried (bare) in soil. Use of 

weathering steel poles near roads that are salted during the winter should be avoided.

In general, weathering steel is intended for and is most often used in a bare, uncoated 

condition. However, those surfaces that will not be boldly exposed to the weather or 

subjected to a wet-dry cycle should be protected from corrosion. Flat, horizontal surfaces 

are particularly vulnerable. Also, in areas where ground cover will grow to a height 

where it will contact the pole and rub the protective weathering steel coat off, or in areas 

where the vegetation will keep the pole moist, the steel surface should be protected from 

corrosion by application of a coating. For direct embedded steel poles, the polyurethane 

coating may have to be extended above the top of the ground sleeve to protect the 

weathering steel pole from moisture entrapped by vegetation or rubbing by groundcover.
Bulletin 1724E-204

Appendix A

Page 7

If the pole is to be embedded in concrete, the interface between the pole, concrete, and 

the atmosphere should be protected in such a way as to prevent water leakage between 

the concrete and steel. Otherwise, moisture would remain and possibly cause corrosion 

at the same rate as carbon steel.

Blast cleaning after fabrication of a weathering steel pole will help to assure a cleaner, 

more uniform, weathering appearance in a shorter period of time.

Grounding 

When poles are direct embedded, this specification requires a polyurethane coating to be 

applied to the exterior surface of the embedded portion of the pole. This coating will 

tend to insulate the pole from the ground and as such, supplemental grounding is 

necessary. When the pole is galvanized and there is no coating on the embedded portion 

of the pole, the pole may be used as the pole ground. If the foundation is a concrete 

caisson, a separate ground should be installed. 

Use of copper or copper clad ground wire and rods should be avoided with direct 

embedded poles.

Additional Protection

The owner or owner's representative should determine if the embedded poles should be 

protected by anodes. If it is necessary, requirements for sacrificial anodes and their 

installation should be incorporated in the construction specification.

6. Section 5.h - Inspection And Testing (no comments)

7. Section 5.i - Structure Testing

An option is available in the specification for full-scale testing of a structure or structures. 

For a manufacturer which has been designing and fabricating steel poles with the same 

processes for a number of years, the need for testing of a steel pole is questionable. 

Structure testing may be appropriate in cases where there are unusual requirements, new 

fabrication techniques, or where there are numerous tangent structures of the same or 

similar design.

8. Section 5.j - Shipping 

The owner may wish to order 5 percent overage of all fastening hardware.

Lumber treated with salts (Ammoniacal copper arsenate, ACA, Ammoniacal copper zinc 

arsenate, ACZA, and Chromated copper arsenate, CCA) to retard “decay or fire” will 

chemically attack the steel. Urethane foam or some foams containing fire retardants

should also not be used in packaging and shipping. When these materials become wet, 

they become very corrosive.
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Appendix A

Page 8

9. Section 6 - Information To Be Supplied By The Manufacturer With The Proposal 

In order to properly evaluate bids, the specification requires certain information to be 

supplied with the bid. This information may be supplied on the preliminary drawings 

from the bidder. If the forms in Attachment B are used, one will be able to quickly 

review the information on the forms and simultaneously compare the information from 

the different manufacturers.

10. Section 7 - Approval, Acceptance, and Ownership (no comments)
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Appendix B

Page 1

APPENDIX B

EXAMPLES OF ATTACHMENTS A & B

OF THE SPECIFICATIONS 
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Appendix B

Page 2

Attachment A Example

(See Hard Copy of Attachment A Example)
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Appendix B

Page 3

Attachment B Example

(See Hard Copy of Attachment B Example)

BLANK PAGE

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Appendix C

Page 1

APPENDIX C

SELECTED SI-METRIC CONVERSIONS
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Appendix C

Page 2

Selected SI-Metric Conversions

AREA

 To Convert From To Multiply By

circular mil (cmil) square meter (m2) 5.067075 E-10

square centimeter (cm2) square meter (m2) *1.000 E-04

square foot (ft2) square meter (m2) *9.290304 E-02

square inch (in2) square meter (m2) *6.451600 E-04

square kilometer (km2) square meter (m2) *1.000 E+06

square mile (mi2) square meter (m2) 2.589988 E+06

FORCE

 To Convert From To Multiply By 

kilogram force (kgf) Newton (N) *9.806650

kip Newton (N) 4.448222 E+03

pound force (lbf) Newton (N) 4.44822

FORCE PER LENGTH

 To Convert From To Multiply By

kilogram force per

meter (kgf/m) Newton per meter (N/m) *9.806650

pound per foot(lb/ft) Newton per meter (N/m) 1.459390 E+01

DENSITY

 To Convert From To Multiply By

pound per cubic inch (lb/in3) kilogram per cubic 2.767990 E+04

meter (kg/m3)

pound per cubic foot (lb/ft3) kilogram per cubic 1.601846 E+01

LENGTH

 To Convert From To Multiply By

foot (ft) meter (m) 3.048 E-01

inch (in) meter (m) *2.540 E-02

kilometer (km) meter (m) *1.000 E+03

mile (mi) meter (m) *1.609344 E+03

*Exact Conversion
Bulletin 1724E-204

Appendix C

Page 3

Selected SI-Metric Conversions (Cont.)

LOAD CONCENTRATION

 To Convert From To Multiply By 

pound per square inch (lb/in2) kilograms per square meter (kg/m2) 7.030696 E+02

pound per square foot (lb/ft2) kilograms per square meter (kg/m2) 4.788026

ton per square foot (ton/ft2) kilograms per square meter (kg/m2) 9.071847 E+02

PRESSURE

 To Convert From To Multiply By 

kip per square inch (kip/in2) Pascal (Pa) 6.894757 E+06

kip per square foot (kip/ft2) Pascal (Pa) 4.788026 E+04

Newton per square meter (N/m2) Pascal (Pa) *1.000

pound per square foot (lb/ft2) Pascal (Pa) 4.788026 E+01

pound per square inch (lb/in2) Pascal (Pa) 6.894757 E+03

BENDING MOMENT

 To Convert From To Multiply By 

kilogram force meter (kgf-m) Newton meter (N-m) *9.806650

kip-foot (kip-ft) Newton meter (N-m) 1.355818 E+02

pound-foot (lb-ft) Newton meter (N-m) 1.355818

VELOCITY

 To Convert From To Multiply By 

foot per second(ft/s) meter per second (m/s) *3.048 E-01

kilometer per hour (km/h) meter per second (m/s) 2.777778 E-01

mile per hour(mi/h) meter per second (m/s) 4.437030 E-01

meter per hour(m/h) meter per second (m/s) 2.777778 E-04

*Exact Conversion.