| dc.description.abstract | The study was conducted to assess premature failure of treated electric wooden utility poles in service in Uganda. Wooden poles have been used in Uganda for electricity transmission and telephone lines for over 60 years since their introduction in the early 1950s. It is believed that poles that were supplied several years ago lasted more than 20 years, and some are still standing. However, of recent, there has been frequent reports of premature failures of treated wooden poles in Uganda, with some poles claimed to last less than five years yet some suppliers still give a warranty of more than 20 years. This study was carried out to provide a baseline documentation of performance of treated wooden utility poles and the extent of premature pole failure in Uganda. The objectives of the study included; to determine the number of poles that failed prematurely in service with respect to treatment chemicals used; to assess the cause of pole failure with respect to chemical used for treatment; and to determine the service life of poles that failed prematurely in the last five years. The study involved collection of both primary and secondary data and information from the Eastern, Western, Northern and Central regions of Uganda by reviewing relevant documents, holding key informant interviews with key players in the industry, holding focus group discussion; and field observations during study visits. Key informant interviews included wooden utility poles suppliers (private and government owned pole treatment plants) and government agencies in Uganda such as ERA, REA, UMEME and UEDCL spread across the country. ERA-licensed 11 wooden utility poles suppliers in Uganda were used to constitute the wooden utility poles suppliers in Uganda. A total of 231 poles were sampled. Results showed that creosote treated poles (45%) had more failures compared to CCA (55%). The overall chi-square results indicated there was no significant association between number of poles that failed prematurely and the treatment chemical used. The leading causes of premature pole failure were found to be fungal decay (51.2%) and termite damage (47.1%) while bird nesting and mechanical forces had the least (1.1%) in CCA treated pole. Mechanical damage and attack from bees and other insects had the least contribution to premature pole failure in creosote treated poles. However, 5.9%, 5.1% and 11.8% of the failures of creosote treated poles were attributed to splitting, wind breaking and vandalism respectively. Analysis of variance showed a significant (p<0.05) variation of cause of failure with treatment chemical used. The average service life of the failed poles was found to be 10 years. It was concluded that creosote treated poles (45%) had more failures compared to CCA (55%); there was an association between cause of failure and treatment chemical used, and the leading causes of premature pole failure were found to be fungal decay and termite damage (52.1%, 47.1% and 23.3%, 19.9% in CCA and Creosote respectively). It was recommended that: deliberate policy measures be instituted for purposes of ensuring that wooden utility poles are handled according to set national standards; pole traceability systems be made mandatory in order to avoid unqualified treated pole suppliers; as well as monitoring wooden utility poles in service such that remedial treatment is effected in time. Further research be conducted on moisture content and drying defects at the time of treatment and the quality of chemical used by pole treaters should be investigated.
Key words: Eucalyptus, wood utility poles, premature pole failure, service life, creosote, CCA, wood preservatives | en_US |
