China completes Asia's longest single cave, double track tunnel

China has completed Asia's longest 16-kms single tunnel with double tracks for high-speed trains in the country's northwest Shaanxi province, state media reported today.

The tunnel, the longest of its kind in Asia, cuts through the Qinling Mountains, according to its builders.

It is part of a high-speed rail line that links Xi'an, the provincial capital and Chengdu in China's southwest Sichuan province.

The 643-kms line, with a designed speed of 250 kms per hour, will slash the travel time between the two cities from 16 hours to just three hours, state-run Xinhua news agency reported.