Railway workers conduct safety inspections at the Yiwan railway line overnight on February 25, 2019. /VCG Photo

The Yiwan railway line connects the cities of Yichang and Wanzhou via Lichuan in central China's Hubei Province. /VCG Photo

The railway line is built on steep mountains with karst landform. /VCG Photo

To ensure safety, the line workers at the Enshi line workshop of the section check and repair railway tracks every night. /VCG Photo

Safety inspectors are called "rail doctors" by the Yiwan Railway authorities. /VCG Photo