Electrical workers dangle, overhaul and maintain 500-kilovolt power lines that cross the sea at the city of Zhoushan, East China's Zhejiang Province, on Tuesday.

The lines stretch 58.7 kilometers from a power substation in Zhoushan to another substation in Ningbo. The grid was upgraded from 220 kilovolts in 2019.

Electrical workers overhaul and maintain 500-kilovolt power lines that cross the sea at the city of Zhoushan, East China's Zhejiang Province, on Tuesday.

Electrical workers overhaul and maintain 500-kilovolt power lines that cross the sea at the city of Zhoushan, East China's Zhejiang Province, on Tuesday.

Electrical workers climb to a tower before maintaining the power lines. (Photos: people.com.cn)