Mufindi Woodpoles Plant and Timber Ltd (MWPT) treats and processes their wood products to TZS 661:2001 (BS 4072:1999) and TZS 685:2001 (BS 1990: Part 1), but can also treat to other standards or specifications if required. They have several inspections and tests in place to ensure that the product adheres to the client’s requirements and specifications. A properly treated Wood Pole for use in the telecommunications and electrical distribution networks can have a life expectancy of over 40 years. There are several maintenance practices and rules, which should be followed to ensure the long life of a treated wood pole, both in storage and in the field.
Storage
Treated wood poles should be stored away from continual contact with the ground by wooden supports (old poles or timber). Poles should be stored on level clear ground and away from possible flooding or groundwater at a height of 300mm. They can be layered upwards using similar sizes to conserve on storage area. If poles are to be stored for very long periods, the storage area should be covered, and chemical leakage should be considered if near watercourses or drains.
Maintenance
When a treated wood pole is erected for use in the field, there are several destructive forces that can eventually cause a pole ‘failure’. The main ones are decay, insect attacks, fire and lightening. Most utilities have inspection schedules for their wood pole lines and the following should be used as a guideline and not ‘limited to’ for checks and inspections.
- Decay: Wood poles should be checked regularly for any signs of decay. As this is most prevalent at ground level, good practice is to ‘sound’ the poles with a small hammer at the groundline. A ‘duff’ hollow noise can be heard from a pole, which has internal decay.
- Remedy: Report and record the suspect pole to the utility supervisor. A further inspection should be carried out to ascertain the extent of the decay and potential life span left within the pole. Depending on the extent of damage the pole should be changed repaired or inspected regularly until changing.
- Insect attacks: Insect attacks can usually be seen, and therefore the areas around poles should be inspected for encroaching ants or termites.
- Remedy: Clear around the pole area and if necessary, treat with environmentally sound insecticide.
- Fire: All grasses and twigs etc. should be cleared to an area of about 1.8m diameter around pole bases to prevent the possibility of fire damage during dry seasons.
- Lightening: If poles are erected in areas prone to lightening, during inspections the full length of the pole should be checked, especially the upper regions where damage could occur from a strike.
NB: The above inspections and preventative measures can increase the life of a treated wooden pole. If during these routine checks any of the above are found, they should be documented on inspection sheets and reported to the utility supervisor. Any further action or investigation can then be carried out as per the supervisor’s instruction.
