Rising to a tunnel's challenge

When work began on the Dazhushan Tunnel, the plan was to finish it in five years. That was in 2008 - and construction crews are still digging.

Unexpected difficulties mean the 14.5-kilometer tunnel, a critical juncture on the Dali-Ruili Railway in Yunnan province, is now scheduled for completion in 2021, Xinhua News Agency reported.

The tunnel runs through six faults in the Hengduan Mountains on the Qinghai-Tibet Plateau. It would have been beyond imagination to build on the earth fractures 20 years ago, said You Hongsheng, a spokesman for No 4 Company of China Railway First Group Co, which is digging the tunnel.