Sumatra blackout likely triggered by wind stress on power lines, expert says

A massive power outage across Sumatra is likely due to mechanical stress from high winds on the transmission network, particularly at cable connection points, according to an expert from the Bandung Institute of Technology (ITB).

Dr. Ir. Djoko Darwanto, an observer of power systems at ITB, stated that the characteristics of the disturbance point to mechanical stress in the conductor connection areas. "If we look at the pattern of the disturbance and the location of the damage at the cable connections, weather factors are very likely to have contributed to this event," he said.

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If we look at the pattern of the disturbance and the location of the damage at the cable connections, weather factors are very likely to have contributed to this event.

Initial joint investigations by the National Police's Criminal Investigation Unit, the Forensic Laboratory Center, and PLN identified three potential causes for the transmission cable failure: thermal stress due to weather, issues at the connection points, and mechanical stress from load and wind. Djoko elaborated that while surface winds might seem moderate, wind speeds at the altitude of transmission conductors can be much higher, causing continuous cable oscillations.

"It might not feel extreme at ground level, but in the conductor area, the wind can be strong enough to cause the cables to move and pull on each other. This condition can create repeated pressure on the cables," he explained. This repeated movement, especially under high load, can increase stress at the connection points, which are known to be particularly vulnerable areas in transmission systems due to the combined effects of vibration, temperature changes, and pressure distribution when cables move.

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It might not feel extreme at ground level, but in the conductor area, the wind can be strong enough to cause the cables to move and pull on each other. This condition can create repeated pressure on the cables.