Power workers patrol Harbin metro tunnels overnight to ensure stable operation

Maintenance workers have a meeting before a patrol mission at a station of Metro Line 2 in Harbin, northeast China's Heilongjiang Province, April 29, 2025. As the last subway train of the day returns to the depot, more than 100 power supply maintenance workers from China Railway Construction Electrification Bureau enter their busiest hours in the 28.7-kilometer-long tunnel of Harbin Metro Line 2. 

Subway power supply maintenance has to deal with high-voltage power systems and is done in dusty environment. Routine inspections are often carried out on equipment more than three meters high. It demands workers to be both brave and meticulous. The maintenance works are all carried out between midnight and 4 a.m., with workers patrolling throughout the tunnel.

In the stillness of the night, these maintenance workers work industriously through the underground tunnels, ensuring the stable operation of the metro power supply. (Xinhua/Wang Song)

Maintenance workers Lu Wang (R) and Chi Hailong work at a station of Metro Line 2 in Harbin, northeast China's Heilongjiang Province, April 30, 2025.(Xinhua/Wang Song)

Maintenance worker Lu Wang checks technical parameters during a patrol mission at a station of Metro Line 2 in Harbin, northeast China's Heilongjiang Province, April 30, 2025.(Xinhua/Wang Song)

Maintenance worker He Nao (R) wears a safety device at a station of Metro Line 2 in Harbin, northeast China's Heilongjiang Province, April 29, 2025.(Xinhua/Wang Song)

Maintenance workers patrol at a station of Metro Line 2 in Harbin, northeast China's Heilongjiang Province, April 30, 2025.(Xinhua/Wang Song)

Maintenance worker Zhang Hao works at a station of Metro Line 2 in Harbin, northeast China's Heilongjiang Province, April 30, 2025.(Xinhua/Wang Song)

Maintenance workers Lu Wang (L) and Chi Hailong work at a station of Metro Line 2 in Harbin, northeast China's Heilongjiang Province, April 30, 2025.(Xinhua/Wang Song)

Maintenance worker He Haifei works at a station of Metro Line 2 in Harbin, northeast China's Heilongjiang Province, April 30, 2025.(Xinhua/Wang Song)