LANZHOU－While most people are still asleep, 24-year-old Song Weiying has already begun his work day as a "sand fighter" in the Kumtag Desert in Northwest China.

Also dubbed a "terracotta warrior" or "scavenger," Song is one of the railway maintenance workers for the China Railway Lanzhou Group, stationed on a section of railway passing through the desert in Gansu province.

"Strong winds blow from spring to winter, making it very hard for us to clear the sand on the railway," Song said.

The Dunhuang Railway line, which Song and his colleagues work on, intersects existing railways in Gansu and Qinghai provinces and the Xinjiang Uygur and Tibet autonomous regions to form a circular network in Northwest China.

The section from Yangguan to Shashangou on the Dunhuang line is famous for strong gales. Located in the middle of the desert, the section sometimes gets buried under sand, posing a serious threat to the safety of trains.

The sand fighters' mission is often undertaken in the face of sandstorms and low visibility. At times, conditions are so rough that sand gets into their eyes, ears and mouths.

Song said once he and his colleagues had to rush to their workplace after receiving a wind warning. It took them more than 10 hours to clear the sand, a job that takes a few hours on a normal day.

"The sandstorm was so severe that we couldn't open our eyes and had to grope our way forward. Those moments made me realize what desperation means," Song said.

Unlike Song, co-worker Yu Guohua enjoys the challenge of his job. Yu, who volunteered to become a railway maintenance worker in 1995, said hardships always rekindle his enthusiasm for life.

During a recent sand-clearing operation on the Yangguan-Shashangou section, Yu took off his gloves and proudly showed the calluses on his hands.

"If we don't volunteer, who else will?" he said, as the workers advanced unfazed like camels in the desert.

Xinhua