Sparks fly as a rail mobile flash butt welding machine works on the track of the Guangzhou Metro Line 18 in Guangzhou, South China's Guangdong province, on Dec 16, 2020. A total of 122.6 kilometers of railway tracks will need to be laid for the Guangzhou Metro Line 18, a subway line which is under construction with a maximum designed speed of 160 kilometers per hour. [Photo/Xinhua]
Welding sparks on the track of the Guangzhou Metro Line 18 in Guangzhou, South China's Guangdong province, on Dec 16, 2020. [Photo/Xinhua]
Workers at the construction site of the Guangzhou Metro Line 18 in Guangzhou, South China's Guangdong province, on Dec 16, 2020. [Photo/Xinhua]
A worker measures the flatness of a welded joint on the track at the construction site of the Guangzhou Metro Line 18 in Guangzhou, South China's Guangdong province, on Dec 16, 2020. [Photo/Xinhua]
Workers at the construction site of the Guangzhou Metro Line 18 in Guangzhou, South China's Guangdong province, on Dec 16, 2020. [Photo/Xinhua]
