About ASC O5

About ASC O5

Brief History

ANSI Accredited Standards Committee (ASC) O5 on Specifications and Dimensions for Wood Poles was organized in 1924 by the Bell Telephone System and the U.S. Independent Telephone Association's American Standards Association's (ASA) Telephone Group. The Exchange Carrier Standards Association (ECSA), which later became the Alliance for Telecommunications Industry Solutions (ATIS), accepted sponsorship and Secretariat responsibility for ASC O5 in 1985. The American Wood Protection Association (AWPA) then assumed the role of Secretariat, effective January 1, 2011.


This Committee creates standards for wood poles, crossarms and braces, and glue laminated timber for utility structures. Wood poles continue to be the most cost effective means of providing electrical and telecommunications services for most areas around the world. Today, there are an estimated 100 million wood utility poles in use throughout the United States.

Accredited Standards Committee O5 (ASC O5) is responsible for developing standards for a portion of the electric and telecommunications utilities' outside plant, primarily wood poles and crossarms. ASC O5 membership consists of a balance from three perspectives within the industry: wood pole producers, pole users and general interest members.  The standardization process is governed by the ASC O5 Operating Procedures, which have been accredited by the American National Standards Institute (ANSI).

Recent Activities

In general, the committee continues to develop standards for wood poles and other overhead structural elements, with an aim to increase the durability and reliability of poles, crossarms, braces, and other wood elements while reducing overall costs to the utility industry.

Cost reduction through standards is possible through higher stress tolerance, non-destructive testing of poles, and the use of non-traditional wood resources, such as foreign wood species. These issues are under study by the fiber stress and foreign species subcommittee. Research on through-boring of wood poles designed to extend their service life is being conducted, and the committee will examine the resulting data..

In 2007, a three-year task force to obtain circumference measurements from poles during the manufacturing process was finalized. With the cooperation of pole manufacturers from the major pole producing sections of the country, data were obtained on over 23,000 poles. These pole dimension data were used to complete a derivation of fiber strength values that was published in ANSI O5.1-2008: Wood Poles – Specifications and Dimensions.

The 2006-2007 review effort completed by the Fiber Stress Subcommittee resulted in proposed language for the standard that more clearly addresses the maximum stress point above groundline, the fiber stress height effect, and multi-pole structures.

The other major focus during 2007 was an evaluation of test data received from the Electric Power Research Institute (EPRI) for several species of tropical hardwood poles from Brazil. One interesting potential benefit to the tropical species is that no preservative treatment will be required. A special meeting of the Foreign Species task force and representatives from the tropical hardwood proponents was held mid-year and it was decided to initiate activity to create a new ASC O5 standard that only addresses tropical hardwood species. ASC O5 has issued a letter to the industry that states the range of fiber strength values that are contained in the pole break test data can be used against the tropical hardwood species for those interested in using such hardwoods for pole use.