A railway considered to be China's most difficult and expensive to build started operation Wednesday.

The maiden journey began at 10:18 AM when a train carrying more than 900 passengers left Enshi Station, Hubei Province, for a two-hour journey to Yichang City.

Wednesday's maiden trip covered more than half the 377-km route linking Yichang to Wanzhou District, in neighboring Chongqing Municipality.

Five trains will run the full length Thursday and more trains will be added on Jan. 11 to bring the railway into full operation.

It took about 50,000 workers seven years to dig and complete 159 tunnels and build 253 bridges through a stretch of mountains on the eastern edge of the Yunnan-Guizhou Plateau for the project.

The length of track that runs through bridges and tunnels accounted for about 74 percent of the line's total.

In the most extreme case, it took almost six years to drill a tunnel through Qiyue Mountain due to complex and dangerous geological conditions.

The line, involving 22.7 billion yuan (US$3.41 billion) in total investment, is also China's most expensive railway in terms of cost per kilometer.

It cost about 60 million yuan to build each kilometer, compared with 29 million yuan per kilometer of the Qinghai-Tibet Railway.

The Yichang-Wanzhou railway will cut trips between Chongqing and Wuhan, capital of Hubei, from 22 hours to just five hours. Travel times from other central or east China cities to southwest China will also be significantly shorter, bringing new opportunities for residents who live in the steep and remote mountains.

(Xinhua News Agency December 22, 2010)