'Raise patrolling to cut transmission tower breakdown'

Seeks to to check transmission system failure; calls for education of locals to curb thefts

The Central Electricity Authority (CEA) has made a number of recommendations to deal with instances of breakdown of transmission system. The CEA has suggested that patrolling of lines be stepped up, especially in February and March before the onset of storm and heavy winds. It also recommended that the frequency of patrolling be increased in areas where power theft is rampant. It said the Bureau of Indian Standards be requested for an early completion of revision of the windzone mapping of the country.

The expert committee appointed by the CEA investigated 29 incidents of failure of transmission towers across the country between October 2014 and June 2015 and cited several cases wherein theft or sabotage made the tower structurally weak, leading to failure during high-speed wind, storm, whirlwind and cyclone. The committee said people need to be educated so that they can help transmission companies in patrolling.

The committee observed that most of the failures are linked to high wind speed. It observed that in some cases, the high wind velocity during storm, cyclone and local phenomenon of whirlwind and gale might have exceeded the wind speed for which the towers were originally designed. The committee, however, said such winds are difficult to predict and the probability of such occurrences is low, thus ruling out the need to alter tower design, which could turn out to be uneconomical.

The committee suggested that the wind data available from 800 wind data measurement stations established by the National Institute of Wind Energy could be used for wind zone mapping and estimating wind speed in areas where towers have collapsed. The CEA, along with public and private transmission companies, is expected to hold meeting with National Institute of Wind Energy to discuss wind data could be effectively used.

To avoid soil erosion, the committee called for comprehensive soil investigation as it will help provide proper protection to the transmission towers.

An executive with a transmission company, who did not want to be identified, told Business Standard: “In some cases, review of the design of tower and foundation is also required in view of nature of failure.”