LANZHOU, Sept. 29 (Xinhua) -- A major railway line connecting Lanzhou, capital of northwest China's Gansu Province, with the southwestern metropolis of Chongqing was put into operation on Friday.

At 8:38 a.m., the K4515 train departed from Chongqing heading to Lanzhou. Some 31 minutes later, the K4518 train left Lanzhou for Chongqing.

It took nine years to build the Lanzhou-Chongqing railway line, which has a total length of 886 kilometers.

Trains on the line, which runs through Gansu, Shaanxi and Sichuan provinces, stop at 15 stations.

Travel time between Lanzhou and Chongqing is expected to be cut from 20 hours to around 12 hours, with trains taking just 11 hours to travel between Lanzhou and Chengdu, capital of Sichuan Province.

The railway line runs through some of the most complex mountainous terrain conditions, said Zhen Bingguo from China Railway First Survey and Design Institute Group.

The first international cargo train also left Lanzhou Friday, traveling via the new railway line then continuing to arrive at south China's Guangxi Qinzhou Free Trade Port, from which the cargo will be sent to Vietnam, the Philippines and Indonesia.

A total of 30 cargo trains will make the journey between the two cities during the initial operation stage, carrying 60 million tonnes of goods each year. The travel time for cargo trains will be cut from 2.5 days to just one day.

The first domestic cargo train traveled from Chongqing to Lanzhou on Friday carrying 290 vehicles produced in Chongqing.

Chongqing is the largest car production base in China and the railway will save about 300 yuan (45 U.S. dollars) per car transported to Lanzhou, said Kong Xiangning, general manager of Chongqing Zhongji Automobile Logistics Company.

The Lanzhou-Chongqing railway line runs through 13 national-level and four provincial-level poverty-stricken counties and will play a crucial role in the development of these regions.