Wooden sand barriers have also been built while taller trees planted along the outer areas of the green belt to reduce wind speeds. Shrubs have been planted along the inner areas of the railway line to address the sand problem, Li said.

He Baofeng, head of the railway maintenance team at Qiemo station, said the rail track will lose its elasticity if too much sand gets underneath it. "The problem can make the railway unsafe, so sand control measures are crucial for the Hotan-Ruoqiang railway."

In areas where there are bigger sand dunes and stronger winds, five bridges with a total length of 49.7 km have been built to allow the desert to move underneath and keep the elevated track safe.

Instead of making the bridge piers on site, they were prefabricated and later assembled. It was the first time that this technique was used to build railway bridges. A total of 434 such bridge piers were built, Pu said.

"Prefabricating the concrete piers saved the construction team the trouble of transporting water into the remote desert to mix concrete, and also reduced the impact of sandstorms on their construction," Pu said. "We have done many experiments to finalize the procedure, which has now been standardized and can be used in other rail projects."

More than a year on, the sand control measures have helped to ensure the safe operation of the railway and the safety of the passengers, Pu said. "More railways will be built in Xinjiang, and we are now busy preparing for our next project, which can be even tougher. But the Hotan-Ruoqiang railway has made us confident in taking on more challenging tasks."

Mao Weihua contributed to this story.