CHANGCHUN - For residents in Huojugou village in China's Changbai Mountains, a train whistle is a welcome sound. It means gurgling water in their kitchens and bathhouses.

For 44 years, the mountainous village and several others in Jilin province have relied on a train, with a single locomotive and one tank car, to provide water.

The train commutes between the towns of Songshu and Baihe, nestled deep in Changbai Mountain. Since 1975, it has run more than 1.6 million kilometers, delivering water to more than 2,600 nearby villagers with limited access to clean water.

Although cisterns have been built to store water unloaded from the trains, villagers along the line maintain the tradition of welcoming the train in person, clanking their buckets and bottles.

"Fetching water used to be a big headache. We had to travel to a faraway river to get water and even cut holes in the ice in winter. Then the small train sent water right to our doorsteps," said Li Zuopei, an 80-yearold resident of Yingbishan village.

The water-delivery trains are a special service on the Hunbai Railway, a scenic line that still uses diesel-powered locomotives. It was launched to address the limited access to drinking water in the area, where underground water is not drinkable because of complex mineral components.

"Water coming out of the wells used to give us Kaschin-Beck disease, and we treated every drop of safe water as if it were gold," said Zhou Aiqin, another resident of Huojugou.

Running the train all year is no easy task, especially in winter, when temperatures easily drop below -20 C. Some of the fuel is spent heating the water during the journey to prevent freezing.

"Water often drips onto our clothes and freezes instantly. We cannot bend our arms or legs and have to move like gorillas," said Jia Lin, a veteran worker at the line's Quanyang station.

The train's crew and station workers, like residents along the line, have been attached to the water delivery missions even as demand has shrunk significantly because of improved water infrastructure and the relocation of villagers. The trains now run three times a month, down from three times a week, to serve just 300 residents.

"But as long as the demand exists, our small train will keep on running," said Xin Yuehong, head of Quanyang station.