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O5.3.2008

Solid Sawn-Wood Crossarms & Braces – Specifications & Dimensions

A MERICAN N ATIONAL S TANDARD

FOR

T ELECOMMUNICATIONS

The Alliance for Telecommunication Industry Solutions (ATIS) is a technical planning and standards development organization that is committed to rapidly developing and promoting technical and operations standards for the communications and related information technologies industry worldwide using a pragmatic, flexible and open approach. Over 1,100 participants from over 300 communications companies are active in ATIS’ 22 industry committees and its Incubator Solutions Program. < http://www.atis.org/ >

AMERICAN NATIONAL STANDARD Approval of an American National Standard requires review by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made towards their resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretations should be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute.

Notice of Disclaimer & Limitation of Liability The information provided in this document is directed solely to professionals who have the appropriate degree of experience to understand and interpret its contents in accordance with generally accepted engineering or other professional standards and applicable regulations. No recommendation as to products or vendors is made or should be implied. NO REPRESENTATION OR WARRANTY IS MADE THAT THE INFORMATION IS TECHNICALLY ACCURATE OR SUFFICIENT OR CONFORMS TO ANY STATUTE, GOVERNMENTAL RULE OR REGULATION, AND FURTHER, NO REPRESENTATION OR WARRANTY IS MADE OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR AGAINST INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS. ATIS SHALL NOT BE LIABLE, BEYOND THE AMOUNT OF ANY SUM RECEIVED IN PAYMENT BY ATIS FOR THIS DOCUMENT, WITH RESPECT TO ANY CLAIM, AND IN NO EVENT SHALL ATIS BE LIABLE FOR LOST PROFITS OR OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES. ATIS EXPRESSLY ADVISES ANY AND ALL USE OF OR RELIANCE UPON THIS INFORMATION PROVIDED IN THIS DOCUMENT IS AT THE RISK OF THE USER. NOTE - The user’s attention is called to the possibility that compliance with this standard may require use of an invention covered by patent rights. By publication of this standard, no position is taken with respect to whether use of an invention covered by patent rights will be required, and if any such use is required no position is taken regarding the validity of this claim or any patent rights in connection therewith.

O5.3.2008, Solid Sawn-Wood Crossarms & Braces – Specifications & Dimensions Is an American National Standard developed by the Accredited Standards Committee O5. Published by Alliance for Telecommunications Industry Solutions 1200 G Street, NW, Suite 500 Washington, DC 20005 Copyright © 2008 by Alliance for Telecommunications Industry Solutions All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. For information contact ATIS at 202.628.6380. ATIS is online at < http://www.atis.org >. Printed in the United States of America.

ANSI O5.3.2008

American National Standard for Wood Poles and Wood Products

SOLID SAWN-WOOD CROSSARMS & BRACES – SPECIFICATIONS & DIMENSIONS

Secretariat Alliance for Telecommunications Industry Solutions

Approved July 15, 2008 American National Standards Institute, Inc.

Abstract This standard consists of specifications covering solid sawn-wood crossarms and braces manufactured from coastal Douglasfir grown in the West Coast region and from dense Southern pine.

ANSI O5.3.2008

FOREWORD The information contained in this Foreword is not part of this American National Standard (ANS) and has not been processed in accordance with the American National Standards Institute’s (ANSI’s) requirements for an ANS. As such, this Foreword may contain material that has not been subjected to public review or a consensus process. In addition, it does not contain requirements necessary for conformance to the standard. This standard was developed by Accredited Standards Committee O5 on Specifications for Wood Poles (ASC O5) under the sponsorship of the Alliance for Telecommunications Industry Solutions (ATIS). This Committee was organized in December 1924 and has produced revisions of this pole specification from time to time as required or deemed beneficial. This standard supersedes American National Standard O5.3-2002. ANSI guidelines specify two categories of requirements: mandatory and recommendation. The mandatory requirements are designated by the word shall and recommendations by the word should. Where both a mandatory requirement and a recommendation are specified for the same criterion, the recommendation represents a goal currently identifiable as having distinct compatibility or performance advantages. Suggestions for improvement of this standard will be welcome. They should be sent to ASC O5 Secretariat, c/o ATIS, 1200 G Street, NW, Suite 500, Washington, DC 20005. This standard was processed and approved for submittal to ANSI by Accredited Standards Committee O5 on Specifications for Wood Poles. Committee approval of the standard does not necessarily imply that all Committee members voted for its approval. At the time it processed and approved this standard, the ASC O5 membership was comprised of the following: Nelson Bingel, Chairman Colin McCown, Vice Chairman Steve Barclay and Jean-Paul Emard, ATIS Secretariat and Editors Chad Underkoffler, ATIS Chief Editor S. Terrell, O5 Technical Editor

Name of Representative

Organization Represented

E.D. Williams

A.W. Williams Inspection Co., Inc.

Edward D. Williams Jr.

A.W. Williams Inspection Co., Inc.

Jeffrey D. Linville

American Institute of Timber Construction

R. Michael Caldwell, P.E.

American Institute of Timber Construction

Ron Goff, P.E.

American Institute of Timber Construction

Dean Matthews

American Wood Preservers Institute

Mike Dilbeck

American Wood Protection Association

Les Lonning

American Wood Protection Association

Colin McCown

American Wood Protection Association

Robert C. Patterson, P.E.

American Wood Protection Association

Craig McIntyre

American Wood Protection Association

James J. Healey

American Wood Protection Institution

Borjen Yeh

APA – The Engineered Wood Association

Shannon Terrell

Brooks Manufacturing Co.

Dwayne Carter

Brooks Manufacturing Co.

Gouri Bhuyan, Ph.D.

Canadian Electricity Association

Mary Joe Rodgers

Comcast

JR Gonzales

Comcast

Dave D’Hooge

Edison Electrical Institute

Randy Hopkins

Edison Electrical Institute

Reed Rosandich, P.E.

Edison Electrical Institute

Rob Nelson

EDM International

Lee R. Gjovik

Gjovik Consulting, Inc.

ii

ANSI O5.3.2008 Name of Representative

Organization Represented

Nelson G. Bingel, III

IEEE

Robert O. Kluge

IEEE

Robert C. Peters

IEEE

Andrew Kudick

Intec Services

Robert A. Reisdorff

Laminated Wood Systems, Inc.

H. Michael Barnes

Mississippi Forest Production Lab

H. Martin Rollins

North American Wood Pole Council

James Carter

National Rural Electric Coop Association

Nick Klein

National Rural Electric Coop Association

Bill Latunen

North West Pole & Piling Shippers Association

Jeffrey J. Morrell

Oregon State University

Larry Slavin

Outside Plant Consulting Services

Todd Brown

Rocky Mountain Pole and Treating Association

H. Robert Lash

Rural Utilities Services

Vahid Zakeri

San Diego Gas & Electric

Arthur D. Peralta

Southern California Edison

Robby S. Brown

Southern Pine Inspection Bureau

Ron Cauley

Southern Pressure Treaters Association

Hollis Ervin

Southern Pressure Treaters Association

Joseph Wheat

Southern Pressure Treaters Association

Robert Meyer

State University of New York – Forestry – Syracuse

Trevor Bowmer

Telcordia Technologies

Donald A. Devisser

West Coast Lumber Inspection Bureau

Gerald Paulson

Western Area Power Administration

Karen Rowe

Western Area Power Administration

Tim Durbin

Western Red Cedar Pole Association

Steve Kracht

Western Red Cedar Pole Association

Randy Baileys

Western Wood Preservers Institute

Stephen F. Smith

Western Wood Preservers Institute

Craig Fohlich

Wood Preservation Canada

Henry Walthert

Wood Preservation Canada

iii

ANSI O5.3.2008

TABLE OF CONTENTS PART I -- GENERAL REQUIREMENTS ................................................................................................................................................... 1 1

SCOPE & ORGANIZATION .............................................................................................................................................................. 1 1.1 1.2

SCOPE............................................................................................................................................................................................. 1 GENERAL ORGANIZATION OF THE STANDARD ................................................................................................................................... 1

2 NORMATIVE REFERENCES ................................................................................................................................................................ 1 3

DEFINITIONS ...................................................................................................................................................................................... 2

4

MARKING ............................................................................................................................................................................................ 6 4.2.1 Species Designation ..................................................................................................................................................................... 6 4.2.2 Preservative Designation............................................................................................................................................................. 6

5

TREATMENT .......................................................................................................................................................................................... 7

6

STORAGE............................................................................................................................................................................................. 7

7

QUALITY CONTROL......................................................................................................................................................................... 7

8

REJECTION ......................................................................................................................................................................................... 8

PART II -- DOUGLAS-FIR: SPECIFICATIONS FOR CROSSARMS & BRACES............................................................................... 9 9

SCOPE OF PART II............................................................................................................................................................................. 9

10

OPTIONS & LIMITATIONS (REQUIREMENTS) ..................................................................................................................... 9

11

MATERIAL REQUIREMENTS .................................................................................................................................................... 9 11.1 11.2 11.3 11.4 11.5 11.6 11.7

12

PROHIBITED DEFECTS .................................................................................................................................................................... 10 SEASONING ................................................................................................................................................................................... 10 COMMUNICATION CROSSARMS ...................................................................................................................................................... 10 POWER CROSSARMS & COMMUNICATION DEAD END CROSSARMS ................................................................................................... 10 HEAVY-DUTY TRANSMISSION CROSSARMS ..................................................................................................................................... 13 HEAVY-DUTY BRACES ................................................................................................................................................................... 13 KNOT-SIZE LIMITATIONS ............................................................................................................................................................... 13 MANUFACTURING REQUIREMENTS.................................................................................................................................... 14

12.1 12.2 12.3 12.4

WORKMANSHIP............................................................................................................................................................................. 14 DIMENSIONS, DRILLING DETAILS, AND TOLERANCES ...................................................................................................................... 15 EDGES .......................................................................................................................................................................................... 15 INCISING ....................................................................................................................................................................................... 16

13

SEASONING .................................................................................................................................................................................. 16

14

DESIGNATED FIBER STRENGTH ........................................................................................................................................... 16

PART III -- DENSE SOUTHERN PINE: SPECIFICATIONS FOR CROSSARMS ............................................................................. 19 15

SCOPE OF PART III .................................................................................................................................................................... 19

16

OPTIONS & LIMITATIONS (REQUIREMENTS) ................................................................................................................... 19

17

MANUFACTURING REQUIREMENTS.................................................................................................................................... 19 17.1 17.2 17.3

WORKMANSHIP............................................................................................................................................................................. 19 DIMENSIONS, DRILLING DETAILS, AND TOLERANCES ...................................................................................................................... 19 EDGES .......................................................................................................................................................................................... 20

iv

ANSI O5.3.2008 18

LIMITATIONS .............................................................................................................................................................................. 20 18.1 18.2 18.3 18.4 18.5 18.6 18.7 18.8 18.9 18.10 18.11 18.12 18.13 18.14 18.15 18.16 18.17

CHECKS ........................................................................................................................................................................................ 20 COMPRESSION WOOD .................................................................................................................................................................... 20 CRACKS ........................................................................................................................................................................................ 20 CROSSGRAIN................................................................................................................................................................................. 21 ADVANCED DECAY (DOTE OR ROT) ................................................................................................................................................ 21 DENSITY ....................................................................................................................................................................................... 21 KNOTS .......................................................................................................................................................................................... 21 PITH CENTERS ............................................................................................................................................................................... 21 RED HEART ................................................................................................................................................................................... 21 SAPWOOD ................................................................................................................................................................................ 21 SEASONING .............................................................................................................................................................................. 21 SHAKES ................................................................................................................................................................................... 22 SPLITS ..................................................................................................................................................................................... 22 TORN GRAIN ............................................................................................................................................................................ 22 WANE ...................................................................................................................................................................................... 22 WARP ...................................................................................................................................................................................... 22 WORM HOLES .......................................................................................................................................................................... 22

19

SEASONING .................................................................................................................................................................................. 22

A

GRADING RULES FOR SOUTHERN PINE CROSSARM STOCK............................................................................................ 24

B

TEST SETUP FOR EVALUATION OF CROSSARM BENDING MOR ..................................................................................... 25

C

ADJUSTING TEST RESULTS TO OBTAIN FIBER STRENGTH .............................................................................................. 28

D

BIBLIOGRAPHY ............................................................................................................................................................................... 29

E

REQUIREMENTS FOR CONSIDERATION OF FOREIGN SPECIES INTO O5.3 .................................................................. 30 E.1 E.2

SCOPE........................................................................................................................................................................................... 30 REQUIREMENTS ............................................................................................................................................................................ 30

TABLE OF FIGURES FIGURE 1 - FEATURES OBSERVED DURING GRADING ............................................................................................................................................ 3 FIGURE 2 - CROSSARM SECTIONS ........................................................................................................................................................................ 5 FIGURE 3 - KNOT LIMITATIONS IN HEAVY-DUTY CROSSARMS (SIDE VIEW OF CENTRAL SECTION) ........................................................................ 13 FIGURE 4 - RECOMMENDED DIMENSIONS FOR CROSSARMS WITH ARMS HAVING 2, 4, 6, AND 8 PIN HOLES ............................................................ 17 FIGURE 5 - SAMPLE OF SPECIFICATION PREPARED BY USER ................................................................................................................................ 18 FIGURE 6 - CROSSARM EDGES ........................................................................................................................................................................... 18 FIGURE 7 - TEST SETUP FOR EVALUATION OF CROSSARM BENDING MOR........................................................................................................... 25

TABLE OF TABLES TABLE 1 - DOUGLAS-FIR KNOT-SIZE LIMITATIONS FOR COMMUNICATION AND POWER CROSSARMS [NOT TO EXCEED 12 FEET (3.7M)] [NEITHER FACE TO EXCEED 5-3/4 INCHES (14.6CM) AND THE SUM OF THE ADJACENT FACES NOT TO EXCEED 9-1/2 INCHES (24.1CM)]...................... 12 TABLE 2 - DOUGLAS-FIR KNOT AND WANE LIMITATIONS FOR HEAVY-DUTY CROSSARMS .................................................................................... 14 TABLE 3 - DOUGLAS-FIR KNOT-SIZE LIMITATIONS FOR HEAVY-DUTY BRACES .................................................................................................... 15 TABLE 4 - KNOT-SIZE LIMITATIONS IN SOUTHERN PINE CROSSARMS .................................................................................................................. 20 TABLE 5 - FACTORS FOR DETERMINING FIBER STRENGTH VALUES ...................................................................................................................... 28

v

AMERICAN NATIONAL STANDARD

ANSI O5.3.2008

American National Standard for Wood Poles and Wood Products --

Solid Sawn-Wood Crossarms & Braces – Specifications & Dimensions

PART I -- GENERAL REQUIREMENTS 1

SCOPE & ORGANIZATION

1.1

Scope

This standard consists of specifications covering solid sawn-wood crossarms and braces manufactured from coastal Douglas-fir (Pseudotsuga menziesii - variety menziesii) grown in the West Coast region (i.e., from the summit area of the Cascade Mountains of Washington, Oregon, California, and British Columbia, Canada); and from dense Southern pine of the following species: longleaf pine (Pinus palustris), shortleaf pine (Pinus echinata), loblolly pine (Pinus taeda), and slash pine (Pinus elliottii). The specifications are intended to cover communications crossarms, power crossarms, heavy-duty crossarms, and heavy-duty braces. Crossarms are intended primarily for use as beams. Heavy-duty crossarms may also be used as struts or columns in braced H-frames. Braces are used for tension, compression-bracing, or both.

1.2

General organization of the standard

This standard is divided into three parts: (1) Part I: General requirements and options that are applicable to all crossarms and braces covered in this standard are specified in Part I; (2) Part II: Specific requirements and options relating to crossarms and braces manufactured from Douglas-fir are specified in Part II; and (3) Part III: Specific requirements and options relating to crossarms and braces manufactured from dense Southern pine are specified in Part III.

2 NORMATIVE REFERENCES The following standards contain provisions which, through reference in this text, constitute provisions of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this American National Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.

ANSI O5.3.2008 ASTM D9-05, Standard terminology relating to wood and wood-based products.1) ASTM D198-05a, Standard methods of static tests of lumber in structural sizes.1) ASTM D2915-03, Standard practice for evaluating allowable properties for grades of structural lumber.1) AWPA U1-07, User specification for treated wood.2) AWPA M6-07, Brands used on forest products.2) SPIB, Grading Rules – 2002 Edition, Southern Pine Inspection Bureau.3) SPIB, Special Product Rules for Structural, Industrial and Railroad Freight Car Lumber.3) WCLIB, Standard Grading Rules No. 17: West Coast Lumber Inspection Bureau4)

3

DEFINITIONS

The following definitions are essentially in agreement with those given in ASTM D9-05, WCLIB Standard Grading Rules No. 17, or SPIB Grading Rules, and shall apply to the terms used in this standard. 3.1 brashness: Commonly, the tendency of the wood to fail suddenly under stress, and to break at relatively small deflection across the grain, with little or no splintering. It is also called brittleness. Possible causes of brashness include heat degradation or the presence of decay. Three characteristics indicative of the brashness of a piece are: a) Exceptionally low specific gravity or weight, as compared to average weight for its species; b) An especially small proportional amount of latewood; and c) Fibers with thin walls. 3.2 check: Lengthwise grain separation, usually occurring across or through the growth rings, as a result of seasoning. This is shown in Figure 1. 3.3 close grain grade: A Douglas-fir grade (WCLIB Standard Grading Rules No. 17, paragraph 204-b) requiring an average of approximately 6, but not more than approximately 30, annual growth rings per inch (2.5cm) on either one end or the other of a piece, measured as shown in Figure 1, Rate of growth, as shown in WCLIB Standard Grading Rules No. 17, paragraph 204-d. Pieces averaging 5 rings or more than 30 rings per inch (2.5cm) are accepted as close grain if they average 1/3 or more summerwood.

_____ 1)

Available from American Society of Testing and Materials (ASTM), < http://www.astm.org >.

2)

Available from American Wood Protection Association (AWPA), < http://www.awpa.com >.

3)

Available from Southern Pine Inspection Bureau (SPIB), < http://www.spib.org >.

4)

Available from West Coast Lumber Inspection Bureau (WCLIB), < http://www.wclib.org >.

2

ANSI O5.3.2008

Figure 1 - Features observed during grading

3.4 compression failures: Localized buckling of fibers, produced by the compression of wood along the grain beyond its ultimate capacity. 3.5 compression wood: Abnormal wood growth that frequently occurs on the underside of leaning coniferous trees. It is denser and harder than normal wood, and is characterized by relatively wide growth rings, usually eccentric, and includes what appears to be an exceptional proportion of latewood. In compression wood the contrast in color between earlywood and latewood is usually less than in normal wood. Compression wood is low in strength for its weight and shrinks excessively along the grain compared to normal wood. 3.6 crack: A break or fracture across the grain of the wood. 3.7 crossgrain: Fibers in wood that are not parallel with the long axis of the piece. 3.8 decay: A disintegration of wood substance due to the action of wood-destroying fungi, resulting in loss of strength. Also called dote or rot. 3.8.1 advanced (typical) decay: The older stage of decay in which the disintegration is readily recognized because hardness and other strength properties are reduced. Decided discoloration 3

ANSI O5.3.2008 or bleaching of the rotted wood may be apparent. Unsound red heart is a typical example of advanced decay. 3.8.2 firm red heart: A stage of incipient decay, characterized by a reddish color in the heartwood. 3.8.3 incipient decay: The early stage of decay that has not proceeded far enough to soften or otherwise perceptibly impair the hardness of the wood. Although the wood is invaded and some of its properties may have deteriorated, no visible change has occurred, with perhaps the exception of minor discoloration. Incipient decay can occur in living trees. 3.9 dense material grade: A Douglas-fir grade (WCLIB Standard Grading Rules No. 17, paragraph 204c) requiring an average of approximately 6 or more annual growth rings per inch (2.5cm) and, in addition, 1/3 or more summerwood on either one end or the other of a piece, measured as shown in Figure 1, Rate of growth, in WCLIB Standard Grading Rule No. 17, paragraph 204-d. The contrast in color between the summerwood and springwood must be distinct. Pieces averaging less than 6 annual rings per inch (2.5cm) but not less than 4 are accepted as dense if averaging 1/2 or more summerwood. 3.10 density: Mass (weight) of wood per unit volume. Strength is related to density. Higher working strengths can be assigned to wood when lightweight pieces are eliminated, by specifying limits for rate of growth and minimum percentages of summerwood. See rate of growth. See close grain grade and dense material grade for Douglas-fir. See Annex A for Southern pine. 3.11 dote: See decay. 3.12 earlywood: That portion of the growth ring that is formed during the early part of the season's growth. It is usually less dense, lighter in color, and weaker mechanically than latewood. The term is preferred to springwood. 3.13 equilibrium moisture content (EMC): Moisture content at which the wood is neither gaining nor losing moisture at a given temperature and relative humidity. 3.14 heart center: The pith or center core of the tree. “Free of heart centers” (FOHC) means “without pith” (side-cut). 3.15 heartwood: The inner portion of wood between the pith and the sapwood, composed entirely of nonliving cells. It is usually darker in color and more durable than the sapwood. Heartwood and sapwood are comparable in strength. 3.16 knot: A portion of a branch or limb that has become incorporated in a piece of lumber. The shape of the knot depends on the angle through which the branch was cut. Least diameters determine the size unless otherwise stated. Terms used to describe knots include: 3.16.1 decayed knot: A knot that is softer than the surrounding wood, containing advanced decay. 3.16.2 firm knot: A knot that is solid across its face, containing incipient decay. 3.16.3 fixed knot: A knot that will hold its place in dry lumber under ordinary conditions, but can be moved by pressure, not easily pushed out. 3.16.4 intergrown knot: A knot whose growth rings are partially or completely intergrown on one or more faces with the growth rings of the surrounding wood. 4

ANSI O5.3.2008 3.16.5 knot cluster: Two or more knots grouped together as a unit with the fibers of the wood deflected around the entire unit. A knot cluster is distinct from a group of single knots, in which each is a unit. 3.16.6 loose knot: A knot not held firmly in place by growth or position, that cannot be relied upon to remain in place. 3.16.7 sound knot: A knot that is solid across its face, is as hard as the surrounding wood, and shows no indications of decay. It may vary in color from the natural color of the wood to reddish brown or black. 3.16.8 spike knot: A knot cut lengthwise or diagonally through the long axis of the branch. In a crossarm, the cross-sectional view of the knot appears on one surface of the arm, and the longitudinal view appears on an adjacent surface. The size of a spike knot is considered to be the distance across the end-grain of the knot, between the edge of the arm and a line parallel to the edge. 3.16.9 tight knot: A knot that is so fixed by growth, shape, or position that it will firmly retain its place in the piece. 3.17 latewood: That portion of the annual growth ring that is formed during the latter part of the yearly growth period. It is usually denser, darker in color, and stronger mechanically than earlywood. This term is preferred to summerwood. 3.18 intentionally left blank. 3.19 nail plate: A galvanized metal plate placed on the end-surfaces to prevent split-widening. 3.20 pitch pocket: An opening between growth rings that usually contains, or has contained, resin. 3.21 pith: The small core in the structural center of a log. See heart center. 3.22 rate of growth: The amount of tree growth each year, expressed as the number of growth rings per inch (2.5cm) (see Figure 1). 3.23 red heart: See decay. 3.24 rot: See decay. 3.25 sapwood: The outer portion of wood next to the bark, usually lighter in color than the heartwood, and containing some living cells while the tree is alive. If left untreated, sapwood is as strong as heartwood, but is not naturally durable. 3.26 sections: For ease of description, crossarms are divided into sections as shown in Figure 2.

Figure 2 - Crossarm sections

5

ANSI O5.3.2008 3.27 shake: A lengthwise separation along the grain, the greater part of which occurs essentially between, or through, the growth rings. This is shown in Figure 1. 3.28 skip: An unsurfaced area on dressed lumber. 3.29 split: A lengthwise separation of the wood from one surface to the other. This is shown in Figure 1. 3.30 springwood: See earlywood. 3.31 summerwood: See latewood. 3.32 wane: Bark, or the lack of wood from any cause, on the surface of lumber. 3.33 warp: Any variation from a true or plane surface, including bows, crooks, twists, cups, or any combination thereof, as these terms are defined in WCLIB Standard Grading Rules No. 17, Paragraph 752, and in SPIB Grading Rules, Paragraph 752.

4

MARKING

4.1 All crossarms and braces shall be legibly and permanently marked or branded in characters 3/8 inch (1cm) or larger. Marking or branding shall not be deeper than 1/8 inch (0.3cm) and shall be applied to a wide face. NOTE – All crossarms shall be marked to indicate the top of the arm because greater defects are permitted on the bottom than on the top. Upside-down installation may thus result in less strength. Also, rounded edges offer less resistance to insulated wires that may be pulled over the crossarms during installation. [See 12.3(a) and 17.3 for specifications.]

4.2 Markings or brandings shall include the following information: a) Manufacturer’s name or symbol; b) Year of manufacture; c) Wood species (see 4.2.1); d) Preservative designation as indicated in AWPA Standard M6-07 (see 4.2.2); e) Preservative retention in pounds per cubic foot of preservative. 4.2.1 Species Designation Designation

Species

DF

Douglas-fir

SP

Southern pine*

*The term "Southern pine" (SP) may be used to designate any of the dense pine species named in 1.1.

4.2.2 Preservative Designation Designation C

Preservative Creosote

6

ANSI O5.3.2008 N

Copper Naphthenate

PA

Pentachlorophenol in petroleum (Type A)

PC

Pentachlorophenol in light hydrocarbon solvent (Type C)

SA

Acid Copper Chromate (ACC)

SG

Alkaline Copper Quat, Type C (ACQ-C)

SK

Chromated Copper Arsenate, Type C (CCA-C)

ST

Copper Boron Azole, Type A (CBA-A)

SU

Copper Azole, Type B (CA-B)

SZ

Ammoniacal Copper Zinc Arsenate (ACZA)

4.2.3 Example. (This information may be in some other form or order, if authorized by the purchaser.) ABC Co. 86

(manufacturer and year of manufacture)

DF .6 PC

(species, retention, and preservative)

5 TREATMENT Crossarms and braces are normally treated with a wood preservative to provide protection against insect attack and damage from decay. Suitable preservatives, conditioning and treating requirements, treatment results, and methods for determining the results of treatment are described in AWPA Standard U1-07, and shall be specified as applicable on the purchase order, or the contract, or both. It is intended that specific requirements for the treatment of crossarms and braces with preservative shall be selected from this standard, or from other appropriate standards, and that the requirements shall be included in the purchasing agreement.

6

STORAGE

6.1 For storage of longer than two months, crossarms and braces shall be stacked above ground with enough room to provide adequate ventilation, on preservative-treated or non-decaying skids, in a welldrained area. The stacks should be protected from the sun and weather to minimize checking and physical distortion. If inspected members are to be held in storage for more than 24 hours after they are fabricated but before treatment, they shall be stored under cover. Untreated arms or braces shall be protected from the weather if shipped in open rail cars or other open vehicles. 6.2 Treated crossarms and braces shall be stacked on skids in closed piles, preferably under cover.

7

QUALITY CONTROL

7.1 Inspection and determination of conformance to requirements shall be performed by the manufacturer at the place of manufacture. Inspection may also be performed by the purchaser (or purchaser's representative) at the place of manufacture, the treating plant, or the delivery destination. The supplier shall provide to the purchaser, or to the purchaser's representative, such access as is reasonable and necessary to determine that the material conforms to all specified requirements, and 7

ANSI O5.3.2008 shall furnish all necessary apparatus, labor, and other facilities for making the tests called for without cost to the purchaser. 7.2 Inspection by the purchaser or purchaser’s representative, or waiving of inspection, shall in no way relieve the supplier of the obligation to furnish material in accordance with all specified requirements. 7.3 Inspection for all lumber defects and approved tests for moisture content shall be made before treatment. Reinspection may be made at the discretion of the purchaser or purchaser’s representative following preservative treatment.

8

REJECTION

Crossarms and braces determined not to be in accordance with specified requirements shall be rejected.

8

ANSI O5.3.2008

PART II -- DOUGLAS-FIR: SPECIFICATIONS FOR CROSSARMS & BRACES SCOPE OF PART II

9

This part of the standard consists of specifications for the material and manufacture of Douglas-fir wood crossarms and braces.

10

OPTIONS & LIMITATIONS (REQUIREMENTS)

Attention is directed to both options and limitations (requirements) in the specifications for crossarms and braces of Douglas-fir. When there are options, selection should be made by the purchaser from those available, and should be specified by the purchaser. Depending on use, specifications on limiting characteristics for crossarm types, with minimum crosssection dimensions as noted, are covered in the following subclauses of the standard: Crossarm Type

Finished Cross-section

Subclause

All types

–

11; 11.1-11.2

Communication crossarms

Minimum: 3-1/4 inches (8.3cm) x 4-1/4 inches (10.8cm)

11.3

Power crossarms

Minimum: 3-1/4 inches (8.3cm) x 4-1/4 inches (10.8cm)

11.4

Heavy-duty crossarms

Either dimension exceeds: 5-3/4 inches (14.6cm) and the sum of adjacent faces exceeds 9-1/2 inches (24.1cm)

11.5

Heavy-duty braces

Minimum: 2-3/4 inches (7cm) x 3-3/4 inches (9.5cm)

11.6

Options may be found in the following: Option

Portion of Standard

Cross-section dimension and length

12.2

Incising and depth

12.4

Marking

4

Drilling

12.2

Treatment and preservative

5

Maximum moisture content

11.2 & 13

Seasoning method

13

Other manufacturing requirements are covered in clause 12.

11

MATERIAL REQUIREMENTS

The lumber used shall be of coastal Douglas-fir (Pseudotsuga menziesii – variety menziesii) grown in the West Coast region from the summit area of the Cascade Mountains of Washington, Oregon, California, and British Columbia, Canada. It shall conform to the limitations detailed in this clause for the specific 9

ANSI O5.3.2008 uses. West Coast Lumber Inspection Bureau (WCLIB) Standard Grading Rules No. 17 shall govern in all cases where specific limitations are not stated. Paragraphs from the grading rules are listed under use categories.

11.1

Prohibited defects

The following defects are prohibited: a) Compression wood; b) Compression failure; c) Advanced decay; d) Insect damage5); e) Knot clusters; f)

Low density or brashness;

g) Shakes.

11.2

Seasoning

This is covered in clause 13. ♦ Moisture content, maximum average: 19%. ♦ Moisture gradient, maximum: 5% from center to surface.

11.3

Communication crossarms

Limitations shall conform to those specified in WCLIB Standard Grading Rules No. 17, Paragraph 170a, except as noted: a) Knots: As indicated in Table 1; b) Warp (including bow, cup, crook, and twist): Shall be limited to Medium, as defined in WCLIB Grading Rules No. 17, Paragraph 752, but not in two directions; c) Splits: Not permitted; and d) Checks: On properly seasoned arms, single face checks shall not exceed an average penetration of 1/4 the depth from any face and are limited to 10 inches (25.4cm) long on the top face, and 1/3 the arm length on the other faces. Checks shall not be repeated in the same line of grain in adjacent pin holes. The sum of the average depths of checks occurring in the same plane on opposite faces shall be limited to 1/4 the face depth.

11.4

Power crossarms & communication dead end crossarms

Limitations shall conform to those specified in WCLIB Standard Grading Rules No. 17, Paragraph 170a, except as noted: _____ 5)

Except as permitted in Paragraph 170 of WCLIB Standard Grading Rules No. 17.

10

ANSI O5.3.2008 a) Knots: As indicated in Table 1; b) Warp (including bow, cup, crook, and twist): Shall be limited to Medium, as defined in WCLIB Grading Rules No. 17, Paragraph 752, but not in two directions; c) Splits: Not permitted; and d) Checks: Refer to 11.3(d).

11

ANSI O5.3.2008 Table 1 - Douglas-fir knot-size limitations for communication and power crossarms [not to exceed 12 feet (3.7m)] [neither face to exceed 5-3/4 inches (14.6cm) and the sum of the adjacent faces not to exceed 9-1/2 inches (24.1cm)] Average Knot Diameter (in) Close grain3) Dense Material3)

Class of Knot and Location Round knots1) Single knot, maximum diameter Center Section Top half Lower half End sections

3/4 (1.9cm) 1 (2.5cm) 1-1/4 (3.2cm)

1 (2.5cm) 1-1/4 (3.2cm) 1-1/2 (3.8cm)

Sum of diameters in a 6-inch length, maximum Center section Top half Lower half End sections

1-1/2 (3.8cm) 2 (5.1cm) 2-1/2 (6.4cm)

2 (5.1cm) 2-1/2 (6.4cm) 3 (7.6cm)

Knots intersecting pinholes, max. Center section End sections

5/8 (1.6cm) 1 (2.5cm)

5/8 (1.6cm) 1 (2.5cm)

Loose knots or knot holes2) Center section Top half

Not greater than half the dimensions of round knots given above

Lower half

Not greater than dimensions for round knots given above

Spike knots or spike knot voids Top face

Not over 3/4 inch (1.9cm) wide or 3/8 inch (1cm) deep Shall be graded as equivalent displacement of the structural wood per round knot data above

Elsewhere

NOTES 1 The average diameters above shall be used where a knot shows on two faces. Where a knot shows on one face only, the diameters can be increased 25%. 2 Loose knots and knot holes shall drain water. 3 See clause 3 for requirements of close grain grade and dense material grade for selection of knot size limits.

12

ANSI O5.3.2008

NOTES: 1) 2)

No knot shall exceed 1 inch (2.5cm) in diameter in these two sections. No knot in this section shall exceed ¾ inch (1.9cm) in diameter.

Figure 3 - Knot limitations in heavy-duty crossarms (side view of central section)

11.5

Heavy-duty transmission crossarms

Limitations shall conform to those specified in WCLIB Standard Grading Rules No. 17, Paragraph 169a, except as noted: a) Knots: As indicated in Table 2; b) Warp (including bow, cup, crook, and twist): Shall be limited to Medium, as defined in WCLIB Grading Rules No. 17, Paragraph 752, but not in two directions; c) Splits: Very short; and d) Checks: Single or opposite each other, with a sum total equal to approximately 1/4 the thickness.

11.6

Heavy-duty braces

Limitations shall conform to those specified in WCLIB Standard Grading Rules No. 17, Paragraph 169a, except as noted: a) Warp (including bow, cup, crook, and twist): Shall be limited to Medium, as defined in WCLIB Grading Rules No. 17, Paragraph 752, but not in two directions; b) Knots: As indicated in Table 3; c) Slope: The slope of the grain shall be no more than 1 in 15, exclusive of normal deviation around knots; d) Splits: Very short; and e) Checks: Refer to 11.5(d).

11.7

Knot-size limitations

11.7.1 For heavy-duty crossarm sizes not listed in Table 2, knot-size limitations are listed in WCLIB Paragraph 169a.

,

11.7.2 No knot shall be closer than its own diameter to the pole-mounting holes. 11.7.3 The maximum knot-hole size permitted shall be: 1/2-inch (1.3cm) holes in widths of 4 inches (10.2cm) to 8 inches (20.3cm); and 3/4-inch (1.9cm) holes in widths of 8 inches (20.3cm) and wider. 13

ANSI O5.3.2008 11.7.4 No knot shall exceed 1 inch (2.5cm) in diameter in the two upper-center sections, as shown in Figure 3.

12

MANUFACTURING REQUIREMENTS

12.1

Workmanship

All crossarms and braces shall be of first-quality workmanship, as described in WCLIB Grading Rules No. 17, Paragraph 722, Standard “E” manufacture. Crossarms and braces shall be dressed on four sides, although medium skips on one side are permissible. Splintering around holes resulting from bits breaking through shall be kept to a minimum.

Table 2 - Douglas-fir knot and wane limitations for heavy-duty crossarms Maximum knot size (in) Wide face (Two Sides) Crossarm size (in)

Narrow face (Top and Bottoms) (in)

Edge (in)

Along centerline (in)

Wane (in)

2-5/8 x 7-1/2 (6.7cm x 19.1cm)

5/8 (1.6cm)

1-3/8 (3.5cm)

1-7/8 (4.8cm)

1/2 (1.3cm)

2-5/8 x 9-1/2 (6.7cm x 24.1cm)

5/8 (1.6cm)

1-3/4 (4.4cm)

2-1/4 (5.7cm)

5/8 (1.6cm)

3-5/8 x 7-1/2 (9.2cm x 19.1cm)

3/4 (1.9cm)

1-3/8 (3.5cm)

1-7/8 (4.8cm)

1/2 (1.3cm)

3-5/8 x 8-1/2 (9.2cm x 21.6cm)

3/4 (1.9cm)

1-3/4 (4.4cm)

2-1/4 (5.7cm)

5/8 (1.6cm)

3-5/8 x 9-1/2 (9.2cm x 24.1cm)

3/4 (1.9cm)

1-3/4 (4.4cm)

2-1/4 (5.7cm)

5/8 (1.6cm)

3-5/8 x 11-1/2 (9.2cm x 29.2cm)

3/4 (1.9cm)

2 (5.1cm)

2-1/2 (6.4cm)

3/4 (1.9cm)

4-5/8 x 5-1/2 (11.7cm x 14cm)

1 (2.5cm)

1-1/4 (3.2cm)

1-1/4 (3.2cm)

3/8 (1cm)

5-1/2 x 7-1/2 (14cm x 19.1cm)

1-1/4 (3.2cm)

1-3/8 (3.5cm)

1-7/8 (4.8cm)

1/2 (1.3cm)

14

ANSI O5.3.2008 Table 3 - Douglas-fir knot-size limitations for heavy-duty braces Specific brace sizes Maximum knot diameter

12.2

General brace sizes

Brace cross-section (in)

Narrow face (in)

Wide face (in)

Brace cross-section (in)

Maximum knot diameter (in)

2-3/4 x 3-3/4 (7 x 9.5cm)

1/2 (1.3cm)

3/4 (1.9cm)

2 to 3 (5.1 to 7.6cm)

1/2 (1.3cm)

3-3/8 x 4-3/8 (8.6 x 11.1cm)

3/4 (1.9cm)

1 (2.5cm)

3-1/8 to 4 (7.9 to 10.2cm)

3/4 (1.9cm)

3-3/8 x 5-3/8 (8.6 x 13.7cm)

3/4 (1.9cm)

1-1/4 (3.2cm)

4-1/8 to 5 (10.5 to 12.7cm)

1 (2.5cm)

3-3/4 x 5-3/4 (9.5cm x 14.6cm)

3/4 (1.9cm)

1-1/4 (3.2cm)

5-1/8 to 6 (13 to 15.2cm)

1-1/4 (3.2cm)

3-5/8 x 7-1/2 (9.2 x 19.1cm)

3/4 (1.9cm)

1-1/2 (3.8cm)

6-1/8 to 8 (15.6 to 20.3cm)

1-1/2 (3.8cm)

3-5/8 x 9-1/2 (9.2 x 24.1cm)

3/4 (1.9cm)

1-3/4 (4.4cm)

8-1/8 to 10 (20.6 to 25.4cm)

1-3/4 (4.4cm)

Dimensions, drilling details, and tolerances

The dimensions and drilling details of crossarms or braces shall conform to specifications or drawings supplied by the purchaser. If tolerances for all dimensions and drilling details are not otherwise specified, they shall be in accordance with the drawings and associated Tables of Figure 4. Figure 5 shows a sample drawing demonstrating important features that should be specified to a manufacturer.

12.3

Edges

Edges in crossarms and braces shall be eased as follows: a) Crossarm Edges: The top of the brand (on the side surface) shall be oriented to the top of the arm (see 4.1). The edges shall be as shown in Figure 6. NOTE – Rounded edges on tops of arms serve two purposes. First, they indicate the top of the arm to the inspectors and linemen. This is necessary because greater defects are permitted on the bottom than on the top. Upside-down installation may thus result in lower effective strength. Second, a rounded edge, as shown, offers a minimum of resistance to insulated wires that may be pulled over the crossarm during erection.

b) Brace Edges: All brace edges shall be eased with a minimum radius of 1/8 inch (0.3cm).

15

ANSI O5.3.2008

12.4

Incising

Incising is of value as a means of reducing severe checking, since the incisions may relieve some circumferential stresses. During treatment, incisions provide additional paths for preservative flow, thereby improving treatment. Incisions shall be reasonably clean-cut and their spacing pattern and depth shall be such as to assure uniform penetration of the preservative to the required depth throughout the incised surfaces. The recommended minimum depth of incisions is 1/4 inch (0.6cm) on all faces. Deeper incisions will assure deeper penetration but may possibly damage crossarms. However, there may be times when deeper penetration and maximum retentions and the resultant longer life will be considered more important than maximum strength.

13

SEASONING

13.1 All solid sawn crossarms or braces shall be manufactured from lumber that has been kiln-dried to a moisture content not to exceed a maximum average of 19%. 13.2 The moisture gradient shall be no greater than 5 percentage points between center and outside. Moisture content shall be taken at depths representing the outer half and the inner half of the piece; for example, 1/2 inch (1.3cm) and 1 inch (2.5cm) for power crossarms. 13.2.1 A resistance-type meter with insulated needles shall be used. The meter shall be checked for calibration before and during inspection. 13.2.2 A sample of not less than 20 arms per charge shall be checked for moisture content. 13.2.3 Moisture measurements should be taken at the midpoint between two adjacent pin or bolt holes and away from the ends.

14

DESIGNATED FIBER STRENGTH ♦ Arms covered by Table 1 – 7800 psi (53800 kPa) ♦ Arms covered by Table 2 – 7400 psi (51000 kPa)

These fiber strengths are for the loading configuration described for the MOR test in Annex B, and may be subject to adjustment (increase or decrease) for other loading configurations.

16

ANSI O5.3.2008

NOTE: Normal shrinkage allowance shall be considered using the arm's current moisture content and actual size. Using the average shrinkage allowances for Douglas-fir and Southern Yellow Pine as one percent size change for each four point moisture content change below the fiber saturation point, calculations can be made to determine if the arm met the minimum size at time of manufacture, when the arm was to meet the average moisture content.

Figure 4 - Recommended dimensions for crossarms with arms having 2, 4, 6, and 8 pin holes

17

ANSI O5.3.2008

NOTES: 1) 2)

Holes shall not be more than 1/16 inch (0.2cm) off longitudinal center. All bolt holes shall pass, without forcing, standard galvanized steel bolts of nominal diameters 1/16 inch (0.2cm) less than the specified hole diameters. Bolt holes shall not admit a “no go-gage” 1/32 inch (0.1cm) larger in diameter than the specified hole diameter.

Figure 5 - Sample of specification prepared by user

NOTES: 1)

2)

The two top edges (only) shall be either chamfered or rounded. (The manufacturer may choose the shape preferred.) The two bottom edges may be slightly eased for the entire length, 1/8 in (0.3cm) ± 1/16 in (0.2cm) radius.

Figure 6 - Crossarm edges

18

ANSI O5.3.2008

PART III -- DENSE SOUTHERN PINE: SPECIFICATIONS FOR CROSSARMS 15

SCOPE OF PART III

15.1 This part of the standard consists of specifications for the material and manufacture of dense Southern pine crossarms. 15.2 The specifications in this standard that relate to dense Southern pine are intended to apply to crossarms having cross sections of not more than 4 inches (10.2cm) on one face by not more than 6 inches (15.2cm) on the other face.

16

OPTIONS & LIMITATIONS (REQUIREMENTS)

16.1 Attention is directed to both options and limitations (requirements) in the specifications for crossarms of Southern pine. When there are options, selections should be made by the purchaser from those available, and should be specified by the purchaser. 16.2 These specifications cover crossarms for use throughout the entire United States. Since usage may differ and exposure to decay and insect damage may vary between extremes, it is logical to allow variations in dimension, treatment, and preservative. 16.2.1 Dimensions, length, drilling details, and allowable tolerances shall be specified by the purchaser. (These details are customarily shown by drawings.) NOTE – The drawings in Figure 4 give recommended drilling details and dimensions for crossarm lengths of 4 feet (1.2m), 5 feet-7 inches (1.7m), 8 feet (2.4m), and 10 feet (3m). Suggested cross-section dimensions are 3-1/4 inches (8.3cm) x 4-1/4 inches (10.8cm) ; 3-1/2 inches (8.9cm) x 4-1/2 inches (11.4cm); 3-1/2 inches (8.9cm) x 5-1/2 inches (14cm); and 3-3/4 inches (9.5cm) x 4-3/4 inches (12.1cm). The crossarms with the 3-1/2 inch (8.9cm) x 4-1/2 inch (11.4cm) cross sections and the 3-1/2 inch (8.9cm) x 5-1/2 inch (14cm) cross sections can be produced from standard ALS (American Lumber Standard) lumber sizes.

16.2.2 Manufacturing requirements are covered in clause 17. Limitations on material are covered in 16 and Table 4.

17

MANUFACTURING REQUIREMENTS

17.1

Workmanship

All crossarms and braces shall be of first-quality workmanship, as described in the SPIB Grading Rules, Paragraph 722, Standard "E" manufacture. Crossarms shall be dressed on four sides, although “hit and miss” dressing on the bottom and light skips on one side are permissible. Splintering around holes resulting from bits breaking through shall be kept to a minimum.

17.2

Dimensions, drilling details, and tolerances

The dimensions and drilling details of crossarms shall conform to specifications or drawings supplied by the purchaser. If the tolerances for all dimensions and drilling details are not otherwise specified, they shall be in accordance with those shown in Table B of Figure 4.

19

ANSI O5.3.2008 Table 4 - Knot-size limitations in southern pine crossarms Center section Top half (in)

Lower half (in)

End section (in)

Maximum diameter of tight single knot

1-1/4 (3.2cm)

1-1/2 (3.8cm)

1-3/4 (4.4cm)

Maximum sum of diameters in a 6inch (15.2cm) section

2-1/2 (6.4cm)

3 (7.6cm)

3-1/2 (8.9cm)

Maximum diameter intersecting a pin hole

1/2 (1.3cm)

1/2 (1.3cm)

1 (2.5cm)

(The knot’s own diameter)

(The knot’s own diameter)

1/2 (1.3cm)

of

a

knot

Minimum distance of 3/4-inch (1.9cm) and larger knots and knot holes from the pin holes at the surface of the crossarm

17.3

Edges

The edges of crossarms shall be as shown in Figure 6. NOTE – Rounded edges on the tops of arms serve two purposes. First, they indicate the top of the arm to inspectors and linemen. This is necessary because greater defects are permitted on the bottom than on the top. Upside-down installation may thus result in lower effective strength. Second, a rounded edge offers a minimum of resistance to insulated wire that may be pulled over the crossarm during erection.

18

LIMITATIONS

18.1

Checks

On the top face, continuous checks shall be no wider than 1/8 inch (0.3cm) or less if they intersect end pin holes and the end of the arm, or if they intersect adjacent pin holes. On other faces, checks shall not exceed one-third the length of the arm. The maximum depth of checks shall not exceed half of the width of the arm or, if located on opposite faces, the total depth of the two shall not exceed half the width.

18.2

Compression wood

Compression wood is permitted if covered by 6 growth rings or if located at least 1 inch (2.5cm) from any surface.

18.3

Cracks

Cracks are prohibited.

20

ANSI O5.3.2008

18.4

Crossgrain

Crossgrain may be no steeper than 1 inch (2.5cm) in 10 inches (25cm), exclusive of normal deviation around knots.

18.5

Advanced decay (dote or rot)

Decay is prohibited.

18.6

Density

Only material meeting the requirements for dense lumber in Paragraph 103 of the SPIB Grading Rules for Southern pine lumber shall be accepted. The paragraph is reproduced in Annex A.

18.7

Knots

The following shall be observed: a) Knot clusters are prohibited; b) Unsound knots are prohibited (Sound knot defined in clause 3.); c) Loose knots and knot holes shall drain water; d) Knots in the upper-center section are permitted if not greater than half the dimensions allowed for single tight knots; e) In the lower-center and end sections, knots are permitted if not greater than the dimensions allowed for single tight knots in Table 4; f)

18.8

Spike knots or spike knot cavities on the top face are permitted if not over 3/4 inch (1.9cm) in width or 3/8 inch (1cm) in depth. Elsewhere, knots are permitted only if not greater in depth than half the dimensions allowed for single tight knots in Table 4.

Pith centers

Pith centers are acceptable.

18.9

Red heart

Red heart is prohibited.

18.10 Sapwood There is no limitation on sapwood.

18.11 Seasoning Methods shall be as specified in 19, with moisture content permitted as defined in 19.1(d). 21

ANSI O5.3.2008

18.12 Shakes Shakes are permitted if covered by six annual rings, or if located at least 1 inch (2.5cm) from any surface.

18.13 Splits Splits are prohibited (unless nail-plated on the end surface).

18.14 Torn grain Maximum depth of torn grain shall not exceed 1/16 inch (0.2cm).

18.15 Wane On end sections, maximum wane shall not exceed 1 inch (2.5cm) measured across corners, and wane shall not occur on more than one edge. On center sections, maximum wane shall not exceed 1/2 inch (1.3cm). All bark shall be removed.

18.16 Warp Maximum warp shall not exceed 0.1 inch (0.3cm) in 12 inches (30.5cm) length, and not in two directions.

18.17 Worm holes Worm holes are permitted, provided that they are no more detrimental than allowable loose knots or knot holes.

19

SEASONING

All solid sawn crossarms shall be manufactured from lumber that has been kiln-dried to an average moisture content not to exceed 22%. Steam conditioning for purposes of reducing moisture content shall not be permitted because this process causes excessive warping and checking after the arms have been in service.

19.1 The moisture content of a charge of crossarms shall be determined from moisture meter readings using a resistance-type moisture meter with insulated needles, as follows: a) Tests shall be made before treatment on dried, surfaced arms; b) The insulated needles shall be driven into the center half of the arm to a depth of at least 3/4 inch (1.9cm); c) The moisture test shall be made on each of 20 crossarms of each charge; 22

ANSI O5.3.2008 d) The average meter reading of all arms tested shall be 22% or less. In arriving at this average, only 5% of the crossarms tested may give readings greater than 30%, but none may exceed 35%. 19.2 The moisture content may also be determined by oven-drying a composite sample of 20 borings representing the outer 1.0 inch (2.5cm) of sapwood. The borings shall be taken between the end and brace bolt holes, in the centerline of the side or bottom surface of the arm at least 6 inches (15.2cm) from the end. The samples shall all be taken as far as practical from any hole. The bored holes shall be plugged with treated plugs. 19.3 It is not customary to redry crossarms to specified moisture contents following treatment with a water-borne preservative. However, when such is specified by the purchaser, the arms shall be airseasoned or kiln-dried to an average moisture content of 22% or less. If kiln-drying is used, the kiln temperature shall be limited to a maximum of 150°F (65.5°C).

23

ANSI O5.3.2008 Annex A (informative)

A

GRADING RULES FOR SOUTHERN PINE CROSSARM STOCK

Southern pine crossarm stock is usually purchased by crossarm producers in accordance with the requirements of "Dense Industrial 65" in the SPIB Special Product Rules for Structural, Industrial, and Railroad-Freightcar Lumber. In general, material purchased to this grade will meet the requirements of this specification. However, physical location of defects may make some stock unfit for crossarms supplied under these specifications. Some producers may prefer to use “Dense Industrial 72” or “Dense Industrial 86” and do less sorting to meet the requirements of this specification. Paragraph 103 of the Grading Rules for Southern Pine Lumber defines dense lumber as follows:6) 103.1 Dense lumber shall average on one end or the other of each piece not less than 6 annual rings per inch (2.5cm) and 1/3 or more summerwood (the darker, harder portion of the annual ring) measured on a representative radial line as specified. The contrast in color between springwood and summerwood shall be distinct. Pieces that average not less than 4 annual rings per inch (2.5cm) shall be accepted as dense if they average 1/2 or more summerwood. 103.1 (a) Measurement of density shall be made in such a way as to ensure that the measured radial line is representative. Measurement shall be made over a continuous length of three inches (7.6cm) or as nearly three inches (7.6cm) as is available. The length shall be centrally located in side-cut (pithless) pieces. In pieces containing the pith, the measurement may exclude an inner portion of the radius amounting to 1/4 of the least nominal dimension of the piece.

_____ 6)

Reprinted by permission of Southern Pine Inspection Bureau.

24

ANSI O5.3.2008 Annex B (informative)

B

TEST SETUP FOR EVALUATION OF CROSSARM BENDING MOR

Figure 7 - Test setup for evaluation of crossarm bending MOR

25

ANSI O5.3.2008 Refer to ASTM D198-05a E P'

= =

Modulus of elasticity in bending, lbs./in.2 Total load on the crossarm, lbs. (P' = 2P)

P

=

Half of the total load on the crossarm, lbs.

L

=

Reaction span, in.

a

=

Distance from a reaction to adjacent load point, in.

b

=

Width of the crossarm, in.

h

=

Depth of the crossarm, in.

∆

=

Bending deflection at the centerline, L/2, relative to the end supports, in.

Reprinted, with permission, from the Annual Book of ASTM Standards, copyright American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.

Material Species:

Douglas-fir, southern pine, or any other species as allowed by this Standard. Other species may be proposed for consideration for inclusion into the Standard, but to be considered must be accompanied by data to support intended service longevity and suitability for the intended use.

Specifications:

If materials to be tested do not meet ANSI O5.3, then submission of data in support of designated fiber strength must be accompanied by complete specifications for the material and manufacture.

Sampling:

Per ASTM D2915.

Moisture Content:

Solid Sawn – Average 15-19% (Min. 12% and Max. 22%)

Arm Net Size:

3-1/2" x 4-1/2" x 8'0" (8.9cm x 11.4cm x 2.4m)

Fabrication:

Dried first, then surfaced only, no boring, no treating.

Marking:

The intended "top” of the arm must be marked (see Table 1 Knot Criteria). For bending tests about the major axis, the arms must be loaded in a manner which places the "top” of the arm in tension.

Test Method – Bending MOR Reference Standard:

Per ASTM D198 for methods and procedures.

Orientation:

Tests should be conducted for both major and minor axis bending, to develop fiber strength data applicable to both vertical and longitudinal crossarm loading configurations. Standard crossarms are typically used for buckarm dead end applications which develop severe loading about the minor bending axis. When loading about the major axis, the “top” of the arm must be in tension. Tests may be conducted with the tension face of the arm oriented either up or down as convenience dictates for the test apparatus.

Reaction Span:

Reactions shall be 4" (10.2cm) from the ends of the arm, giving a reaction span of 88" (2.2m).

Load Type & Span:

Two-point load per ASTM D198-05a. Load points shall be 33" (83.8cm) from the reaction points. Load points shall be 22" (55.9cm) apart.

Test Speed:

Ramp or uniform step (5-10 minutes total to failure)

Data To Be Collected or Calculated Actual dimensions of each crossarm, cross section shall be measured with calipers. Moisture content and weight of the crossarm.

26

ANSI O5.3.2008 Slope of grain. Density, rings per inch (2.5cm), % summerwood (less than 1/4, 1/4-1/3, 1/3-1/2, over 1/2). Knot size, location, and displacement, at least for central half-length of the crossarm. Any other notable defects or comments regarding defects. Type and location of bending failure, including sequence. Modulus of elasticity (MOE), based on the measured cross section and monitoring of the deflection of the arm’s neutral axis at the midpoint of its length, relative to the neutral axis at the reaction point 4 inches (10.2cm) from the end. Take note that the MOE cannot be calculated using formula for a simple beam having one concentrated load at its center. Bending Modulus of Rupture (MOR), based on the cross section and the maximum load. MOR and MOE average, standard deviation, and coefficient of variation for each test series.

27

ANSI O5.3.2008 Annex C (informative)

C

ADJUSTING TEST RESULTS TO OBTAIN FIBER STRENGTH

The fiber strength shall be calculated from test data such that there is a 75% confidence that the true mean will be above the calculated value. This may be determined by:

(

X fs = x 1– t V N

)

Where: Xfs = fiber strength x = sample mean t = Value from one sided t distribution for 75% confidence (See Table 5) V = Coefficient of variation N = Sample size Examples of the factor: tV ⎞⎟ ⎛⎜ 1– ⎝ N⎠

For V = 0.15 and 0,20 are also shown in Table 5.

Table 5 - Factors for determining fiber strength values tV ⎞⎟ ⎛⎜ 1– ⎝ N⎠ Sample Size

t

V - 0.15

V = 0.20

3

.816

.929

.906

5

.741

.950

.934

10

.703

.967

.956

15

.692

.973

.964

20

.688

.977

.969

25

.685

.979

.973

30

.683

.981

.975

40

.681

.984

.978

50

.680

.986

.981

≥50

.680

1 − 0.102 / N

1 − 0.136 / N

28

ANSI O5.3.2008 Annex D (informative)

D

BIBLIOGRAPHY

AWPA A5, Standard methods for analysis of oil-borne preservatives.7 AWPA A6, Method for the determination of oil-type preservatives and water in wood. 7 AWPA U1, Use category system: products.7

user specification for treated wood, commodity specification A, sawn

AWPA M2, Standard for inspection of wood products treated with preservatives.7 AWPA P1/P13, Standard for creosote preservative. 7 AWPA P5, Standards for waterborne preservatives.7 AWPA P8, Standards for oil-borne preservatives.7 AWPA P9, Standards for solvents and formulations for organic preservative systems.7

_____ 7

Available from the American Wood Protection Association (AWPA), < http://www.awpa.com >.

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ANSI O5.3.2008 Annex E

(normative)

E

REQUIREMENTS FOR CONSIDERATION OF FOREIGN SPECIES INTO O5.3

E.1

Scope

This requirement covers all crossarms harvested outside the United States and Canada and not presently listed in ANSI O5.3.2008. Information must be submitted demonstrating that the material properties of the species do not vary within the geographic range of the species. Full-scale evaluation of crossarms should be performed on material that has been subjected to the mitigation requirements specified in the United States Department of Agriculture Animal and Plant Health Inspection Service (APHIS) regulations.

E.2

Requirements 1.

SPECIES:

Must provide the botanical name and the common name.

2.

LOCATION:

Describe in detail the location material will come from. At a minimum it must include country of origin and boundaries.

3.

SPECIES VERIFICATION:

Species verification must accompany the data package. The verification must be done microscopically by an independent third party or an alternative must be submitted to the subcommittee for approval. The independent third party must be knowledgeable in forest anatomy (i.e., government forest products lab, university lab, or other qualified organization).

4.

USE:

List all standards, both foreign and United States, where the proposed species is presently approved for structural use.

5.

MATERIAL REQUIREMENTS:

Identify all material requirements that differ from ANSI O5.3.2008 (i.e. slope of grain, knots, density, knot location, etc.).

6.

MANUFACTURING:

Provide information on the effect of manufacturing on the strength of the wood, including seasoning, steaming, and kiln drying.

7.

FULL-SCALE EVALUATION:

Full-scale structural evaluation testing shall be conducted in accordance with ASTM D198-05a (or latest edition). Data previously attained by alternative test methods and/or proposed alternative methods of full-scale testing shall be accepted provided it is reviewed and determined to be equivalent to ASTM D-198-05a (or latest edition) by the ASC O5 Committee. In that regard, prior data must include full-scale crossarm bending strength data and a detailed description of the testing procedure. Proposed alternative evaluation methods must include a complete description of the test procedures and comply with sample collection methods as outlined in ASTM D-198-05a (or latest edition). Species qualification testing shall include the full range of sizes in accordance with ANSI O5.3.2008, or include only those predominant sizes anticipated to be supplied. Sample sizes shall be sufficient to support a standard error no greater than 10% on the estimate of the lower 5% tolerance value in accordance with ASTM 2915-03 (or latest edition).

8.

ENGINEERING CERTIFICATION:

The full-scale evaluations and fiber strength calculations must be reviewed by an independent third party with a professional engineer’s certification. The engineer must be registered in the U.S. or Canada and be experienced in timber mechanics. Full-scale break tests and strength data -- modulus of rupture (MOR) and modulus of elasticity (MOE) -- must accompany the professional engineer’s certification.

9.

SOURCE CERTIFICATION:

An independent third-party certification verifying the source of the wood must be provided. The proponent shall describe how the source of each crossarm will be controlled and assured. Each shipment or lot must be certified.

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