A train chugs on the railway bridge across Lhasa River with the Potala Palace in the background in Lhasa, capital of northwest China's Tibet Autonomous Region, on June 20, 2006. The 928.85-meter-long Lhasa River Railway Bridge, with the main span of 108 meters, is a landmark on the Qinghai-Tibet Railway, which is expected to start operation on July 1.

A train chugs on the railway bridge across Lhasa River with the Potala Palace in the background in Lhasa, capital of northwest China's Tibetan Autonomous Region, on June 20, 2006. The 928.85-meter-long Lhasa River Railway Bridge, with the main span of 108 meters, is a landmark on the Qinghai-Tibet Railway, which is expected to start operation on July 1.

The Lhasa River Railway Bridge is under construction in Lhasa, capital of northwest China's Tibetan Autonomous Region, in this file photo taken in 2005. The 928.85-meter-long railway bridge, with the main span of 108 meters, is a landmark on the Qinghai-Tibet Railway, which is expected to start operation on July 1.

The Lhasa River Railway Bridge is under construction in Lhasa, capital of northwest China's Tibetan Autonomous Region, in this file photo taken in 2005. The 928.85-meter-long railway bridge, with the main span of 108 meters, is a landmark on the Qinghai-Tibet Railway, which is expected to start operation on July 1.

Construction workers build the Lhasa River Railway Bridge in Lhasa, capital of northwest China's Tibetan Autonomous Region, in the file photo taken in 2005. The 928.85-meter-long railway bridge, with the main span of 108 meters, is a landmark on the Qinghai-Tibet Railway, which is expected to start operation on July 1.