How often should wood poles be inspected?

A normal inspection cycle is 5 years, but this can be adjusted based on local conditions, climate, and age of the poles (Clause 5.2).

What are the main causes of wood pole deterioration?

The primary causes are fungal decay (rot) and attack by termites or other insects, particularly at and below the ground line where moisture levels are favorable for them (Clause 4).

What is 'sounding' a pole?

It involves tapping the pole surface with a hammer from the ground up to a height of about 2 meters to detect internal voids or decay, which produce a hollow sound compared to the solid ring of sound wood (Clause 5.4.2).

When should a pole be replaced?

A pole should be considered for replacement when the remaining sound wood is insufficient to provide the required strength to withstand design loads. This is determined after a detailed inspection (Clause 7).

IS 6711

: 1972

Code of practice for maintenance of wood poles for overhead power and telecommunication lines

CurrentSpecializedCode of PracticeMEP · Timber and Timber Stores

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This standard provides guidelines for the maintenance of wood poles used in overhead power and telecommunication lines. It covers the causes of deterioration, procedures for systematic inspection, and methods for remedial and preventive treatments to ensure structural integrity and extend service life.

Code of practice for maintenance of wood poles for overhead power and telecommunication lines

Quick Reference Values

Normal inspection cycle5 years

Inspection drilling depth below ground line500 mm

Inspection hole diameter15 to 20 mm

Pole sounding methodTapping with a hammer from ground level up to 2m

Re-treatment cycle10 to 15 years for poles in service

Practical Notes

The ground-line section (approx. 300 mm above to 500 mm below ground) is the most critical area for decay and requires thorough inspection.

Sounding the pole with a hammer is a quick, preliminary method to detect internal rot, but should be followed by boring for confirmation, especially if a dull or hollow sound is heard.

Always de-energize power lines or maintain safe clearance as per regulations before commencing any maintenance work on poles.