IS 876 : 1992Wood Poles for Overhead Power And Telecommunication Lines

Q: How are timber poles classified under IS 876?

They are classified into different strength classes based on their dimensions and ultimate breaking load capacity.

Q: Can any type of wood be used for overhead lines?

No, only specific durable and treatable timber species listed in the code (e.g., Sal, Teak, specific pines) are permitted.

Q: Is preservative treatment mandatory?

Yes, all wood poles must undergo preservative treatment as per IS 401 before deployment to ensure adequate service life.

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ANSI O5.1 · EN 14229 · AS/NZS 4792

CurrentSpecializedSpecificationStructural Engineering · Timber and Timber Stores

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IS 876:1992 is the Indian Standard (BIS) for wood poles for overhead power and telecommunication lines. This standard details the specifications, timber species, permissible defects, dimensions, and testing requirements for wood poles used in overhead electric power transmission and telecommunication lines. It emphasizes strength classification and mandatory preservative treatments for durability.

Wood Poles for Overhead Power And Telecommunication Lines

Overview

Status: Current
Usage level: Specialized
Domain: Structural Engineering — Timber and Timber Stores
Type: Specification

International equivalents

ANSI O5.1-2017 · American National Standards Institute (ANSI), USA EN 14229:2010 · European Committee for Standardization (CEN), Europe AS/NZS 4792:2006 · Standards Australia / Standards New Zealand, Australia & New Zealand

Typically used with

IS 399 IS 401

Also on InfraLens for IS 876

4Key values 2Tables 3FAQs

Practical Notes

! Timber poles must be properly treated with chemical preservatives (as per IS 401) to prevent premature failure from termite attack or fungal decay, especially at the ground-line.

! Inspect incoming poles strictly for sweep, crook, and large knots, as excessive defects significantly reduce the buckling capacity of the pole.

! Poles are categorized into strength classes based on their ultimate breaking load; the engineer must select the class based on the wind zone and span length.

Frequently referenced clauses

Cl. 4Classification of Poles Cl. 5Species of Timber Cl. 6Defects and Tolerances Cl. 8Preservation Treatment

timberwoodpreservatives

International Equivalents

Similar International Standards

ANSI O5.1-2017American National Standards Institute (ANSI), USA

HighCurrent

American National Standard for Wood Poles - Specifications and Dimensions

Covers material requirements, dimensions, defects, and preservation for wood utility poles.

EN 14229:2010European Committee for Standardization (CEN), Europe

MediumCurrent

Structural timber - Wood poles for overhead lines

Specifies requirements for wood poles for overhead lines, but with a performance-based strength class approach.

AS/NZS 4792:2006Standards Australia / Standards New Zealand, Australia & New Zealand

HighCurrent

Hardwood and cypress poles for overhead lines

Specifies requirements for hardwood and cypress poles, focusing on regional species and strength groups.

BS 1990-1:1984British Standards Institution (BSI), UK

HighWithdrawn

Wood poles for overhead power and telecommunication lines - Specification for softwood poles

Provided detailed specifications for softwood poles, similar in prescriptive nature to IS 876.

Key Differences

≠IS 876 classifies poles based on specific Indian timber species and dimensions, while standards like ANSI O5.1 use a numerical class system (e.g., Class 1, 2, H1) based on strength-related dimensions (circumference), and EN 14229 uses performance-based strength classes (A, B, C) defined by material properties.

≠The specified timber species are entirely regional. IS 876 lists Indian species like Sal, Teak, and Chir, whereas ANSI O5.1 focuses on North American species like Southern Pine and Douglas Fir, and AS/NZS 4792 on Australian Eucalypts.

≠IS 876 specifies preservative treatment by referencing Indian Standards (e.g., IS 401 for preservation code, IS 10013 for CCA). In contrast, ANSI O5.1 refers to the American Wood Protection Association (AWPA) standards, and EN 14229 refers to European standards like EN 351-1.

≠The method for determining acceptable sweep (bow) differs. IS 876 provides a simple table of maximum permissible sweep based on pole length (e.g., 75mm for a 9m pole). ANSI O5.1 defines sweep by a single plane rule, stating the pole must not deviate from a straight line connecting the surface at the top and the groundline by more than one inch for every 10 feet of length.

Key Similarities

≈All standards have the same fundamental purpose: to ensure the quality, structural integrity, and durability of wood poles used for supporting overhead power and telecommunication lines.

≈All standards mandate preservative treatment for non-durable wood species to protect against decay and insects, and commonly specify preservatives like Creosote and Copper Chrome Arsenate (CCA), though via different reference standards.

≈Each standard provides detailed limits on natural wood defects that compromise strength, such as knots, checks, splits, slope of grain, and insect damage.

≈All standards require poles to be marked or branded with key information for traceability, typically including the supplier, year of treatment, species, and size/class.

≈The core dimensional parameters specified are consistent across the standards, including total length, minimum top circumference/diameter, and circumference at a specified distance from the butt, which are critical for structural calculations.

Parameter Comparison

Parameter	IS Value	International	Source
Pole Classification Method	Based on species and dimensional tables (length, top circumference, circumference at 1.8m from butt).	Numerical class system (e.g., Class 1-10) defining minimum circumferences at top and 6 ft from butt, irrespective of species.	ANSI O5.1-2017
Primary Timber Species	Sal (Shorea robusta), Teak (Tectona grandis), Deodar (Cedrus deodara), Chir (Pinus roxburghii).	Southern Pine, Douglas Fir, Western Red Cedar, Ponderosa Pine.	ANSI O5.1-2017
Strength Designation	Strength is implicit based on the specified dimensions for a given timber species.	Explicit strength classes (e.g., Class A, B, C) with characteristic bending strength values (e.g., 48 N/mm² for Class A).	EN 14229:2010
Preservative Treatment Standard	IS 401 (Code of practice for preservation of timber), IS 10013 (Specification for CCA).	AWPA U1 (Use Category System: User Specification for Treated Wood) and other AWPA standards.	ANSI O5.1-2017
Moisture Content (at treatment)	Not specified directly, but states seasoning should be done as per IS 1141.	Must be seasoned before treatment so that preservative penetration and retention are not impaired. Often specified as fiber saturation point or below (e.g., <25-30%).	ANSI O5.1-2017
Limit on Sum of Knot Diameters	Sum of diameters of all knots in any 30 cm length shall not exceed 1/4 of the circumference of the pole at that section.	The sum of the sizes of all knots in any 1-foot section shall not exceed the specified limits in a table, which vary by pole class (e.g., 8 inches for Class 1-3).	ANSI O5.1-2017

⚠ Verify details from original standards before use

Key Values4

Quick Reference Values

Depth of plantingGenerally 1/6th of the pole length

Moisture content before treatmentMaximum 25%

Tolerance on length+50 mm, -25 mm

Maximum sweep limitMust not exceed 1 in 60 of length

Tables & Referenced Sections

Key Tables

Table 1 - Species of Timber for Poles

Table 2 - Dimensions and Classes of Poles

Key Clauses

Clause 4 - Classification of Poles

Clause 5 - Species of Timber

Clause 6 - Defects and Tolerances

Clause 8 - Preservation Treatment

Frequently Asked Questions3

How are timber poles classified under IS 876?+

They are classified into different strength classes based on their dimensions and ultimate breaking load capacity.

Can any type of wood be used for overhead lines?+

No, only specific durable and treatable timber species listed in the code (e.g., Sal, Teak, specific pines) are permitted.

Is preservative treatment mandatory?+

Yes, all wood poles must undergo preservative treatment as per IS 401 before deployment to ensure adequate service life.

QA/QC Inspection Templates

📋

QA/QC templates coming soon for this code.

Browse all 300 templates →

IS 876 : 1992Wood Poles for Overhead Power And Telecommunication Lines

PDF Google Compare BIS Portal

Link points to Internet Archive / others. Not hosted by InfraLens. Details

ANSI O5.1 · EN 14229 · AS/NZS 4792

CurrentSpecializedSpecificationStructural Engineering · Timber and Timber Stores

PDF Google Compare BIS Portal

Link points to Internet Archive / others. Not hosted by InfraLens. Details

Wood Poles for Overhead Power And Telecommunication Lines

Overview

Status: Current
Usage level: Specialized
Domain: Structural Engineering — Timber and Timber Stores
Type: Specification

International equivalents

Typically used with

IS 399 IS 401

Also on InfraLens for IS 876

4Key values 2Tables 3FAQs

Practical Notes

! Timber poles must be properly treated with chemical preservatives (as per IS 401) to prevent premature failure from termite attack or fungal decay, especially at the ground-line.

! Inspect incoming poles strictly for sweep, crook, and large knots, as excessive defects significantly reduce the buckling capacity of the pole.

! Poles are categorized into strength classes based on their ultimate breaking load; the engineer must select the class based on the wind zone and span length.

Frequently referenced clauses

Cl. 4Classification of Poles Cl. 5Species of Timber Cl. 6Defects and Tolerances Cl. 8Preservation Treatment

timberwoodpreservatives

International Equivalents

Similar International Standards

ANSI O5.1-2017American National Standards Institute (ANSI), USA

HighCurrent

American National Standard for Wood Poles - Specifications and Dimensions

Covers material requirements, dimensions, defects, and preservation for wood utility poles.

EN 14229:2010European Committee for Standardization (CEN), Europe

MediumCurrent

Structural timber - Wood poles for overhead lines

Specifies requirements for wood poles for overhead lines, but with a performance-based strength class approach.

AS/NZS 4792:2006Standards Australia / Standards New Zealand, Australia & New Zealand

HighCurrent

Hardwood and cypress poles for overhead lines

Specifies requirements for hardwood and cypress poles, focusing on regional species and strength groups.

BS 1990-1:1984British Standards Institution (BSI), UK

HighWithdrawn

Wood poles for overhead power and telecommunication lines - Specification for softwood poles

Provided detailed specifications for softwood poles, similar in prescriptive nature to IS 876.

Key Differences

Key Similarities

≈All standards have the same fundamental purpose: to ensure the quality, structural integrity, and durability of wood poles used for supporting overhead power and telecommunication lines.

≈Each standard provides detailed limits on natural wood defects that compromise strength, such as knots, checks, splits, slope of grain, and insect damage.

≈All standards require poles to be marked or branded with key information for traceability, typically including the supplier, year of treatment, species, and size/class.

Parameter Comparison

Parameter	IS Value	International	Source
Pole Classification Method	Based on species and dimensional tables (length, top circumference, circumference at 1.8m from butt).	Numerical class system (e.g., Class 1-10) defining minimum circumferences at top and 6 ft from butt, irrespective of species.	ANSI O5.1-2017
Primary Timber Species	Sal (Shorea robusta), Teak (Tectona grandis), Deodar (Cedrus deodara), Chir (Pinus roxburghii).	Southern Pine, Douglas Fir, Western Red Cedar, Ponderosa Pine.	ANSI O5.1-2017
Strength Designation	Strength is implicit based on the specified dimensions for a given timber species.	Explicit strength classes (e.g., Class A, B, C) with characteristic bending strength values (e.g., 48 N/mm² for Class A).	EN 14229:2010
Preservative Treatment Standard	IS 401 (Code of practice for preservation of timber), IS 10013 (Specification for CCA).	AWPA U1 (Use Category System: User Specification for Treated Wood) and other AWPA standards.	ANSI O5.1-2017
Moisture Content (at treatment)	Not specified directly, but states seasoning should be done as per IS 1141.	Must be seasoned before treatment so that preservative penetration and retention are not impaired. Often specified as fiber saturation point or below (e.g., <25-30%).	ANSI O5.1-2017
Limit on Sum of Knot Diameters	Sum of diameters of all knots in any 30 cm length shall not exceed 1/4 of the circumference of the pole at that section.	The sum of the sizes of all knots in any 1-foot section shall not exceed the specified limits in a table, which vary by pole class (e.g., 8 inches for Class 1-3).	ANSI O5.1-2017

⚠ Verify details from original standards before use

Key Values4

Quick Reference Values

Depth of plantingGenerally 1/6th of the pole length

Moisture content before treatmentMaximum 25%

Tolerance on length+50 mm, -25 mm

Maximum sweep limitMust not exceed 1 in 60 of length

Tables & Referenced Sections

Key Tables

Table 1 - Species of Timber for Poles

Table 2 - Dimensions and Classes of Poles

Key Clauses

Clause 4 - Classification of Poles

Clause 5 - Species of Timber

Clause 6 - Defects and Tolerances

Clause 8 - Preservation Treatment

Frequently Asked Questions3

How are timber poles classified under IS 876?+

They are classified into different strength classes based on their dimensions and ultimate breaking load capacity.

Can any type of wood be used for overhead lines?+

No, only specific durable and treatable timber species listed in the code (e.g., Sal, Teak, specific pines) are permitted.

Is preservative treatment mandatory?+

Yes, all wood poles must undergo preservative treatment as per IS 401 before deployment to ensure adequate service life.

QA/QC Inspection Templates

📋

QA/QC templates coming soon for this code.

Browse all 300 templates →

IS 876 : 1992Wood Poles for Overhead Power And Telecommunication Lines

Overview

International Equivalents

Key Values4

Tables & Referenced Sections

Related Resources on InfraLens

Frequently Asked Questions3

QA/QC Inspection Templates

IS 876 : 1992Wood Poles for Overhead Power And Telecommunication Lines

Overview

International Equivalents

Key Values4

Tables & Referenced Sections

Related Resources on InfraLens

Frequently Asked Questions3

QA/QC Inspection Templates