Tuesday, April 11, 2017

A Bridge over the River Dadu

The crossing of the Dadu River in Luding, in today’s Garze Tibetan Autonomous Prefecture (Sichuan province) was vital to the Red Army during the Long March in 1935.
The soldiers of the Fourth Regiment of the Chinese Workers and Peasants' Army eventually crossed the bridge located some 80 kilometers west of the city of Ya'an.
According to Wikipedia: “Fleeing from pursuing Chinese Nationalist forces, the communists found that there were not enough boats to cross the Dadu River. Thus, they were forced to use Luding Bridge, a Qing dynasty suspension bridge built in 1701. The bridge consisted of thirteen heavy iron chains with a span of some 100 yards. Thick wooden boards lashed over the chains provided the roadway across the bridge.”
The online encyclopedia continues: “On the morning of May 30, 1935 the 4th regiment of [later Marshal] Lin Biao's 2nd division, 1st Corps of the Chinese Red Army received an urgent order from general headquarters: Luding Bridge must be captured on May 29, 1935, one day ahead of the original schedule.”
The history of the Long March says that the 4th regiment had to march 120 km in less than 24 hours: “Along the way, they engaged and defeated numerous nationalist forces which blocked their path. On the dawn of May 29, 1935, Lin Biao's troops reached the bridge, only to discover that local warlords allied with the ruling Kuomintang had removed most of the planks on the bridge.”
To cut a long story short, the Reds finally crossed the bridge on the Dadu; it was a resounding for Lin Biao’s (and Mao’s) troops.



The New Luding Bridge
The bridge has come again in the news.
According to China News Network, the new Yakang (Ya’an to Kangding) Expressway will cross the Dadu River at Luding on the Xingkang Bridge.
The high-altitude area is a “high seismic intensity zone, with complex wind environment,” says the Chinese website.
Crossing a wide reservoir from a downstream dam just north of Luding city, the giant Dadu He suspension bridge will be the largest structure on the Yakang expressway.
The Kanding route is especially difficult to construct with an amazing 82% of the road on bridges or in tunnels. Located at kilometer 99, the alignment chosen for the Dadu He Bridge resulted in an unusual design for the east end where the anchorages had to be placed high up inside the steep mountain slope. To avoid compromising the strength of the deep underground anchorage, the engineers split the east-west lanes apart into tunnels separated by more then 100 meters, keeping the alignment off to the sides of the cable anchorage. The deck of the Dadu He Bridge is approximately 235 meters above the full lake level or 280 meters to the original level of the Dadu River.

Luding is one of the most famous cities in Western China for its legendary chain bridge of 100 meters that ranked among the longest suspension bridges in the world since its completion in 1701.
Several historic battles have taken place at or near the chain bridge due to its strategic importance, we just mentioned the one during the Long March.
The Dadu He Bridge at Luding is one of at least a dozen major suspension bridges that have been constructed in China since 2009 that have span lengths of approximately a kilometer or longer and deck heights of 200 to 500 meters.
The length of the Luding Bridge is 1,411 meters. It uses prefabricated parallel steel wire unit; each cable has a length of 1754 meters; a single main cable weight 5234.6 tons; the design bearing capacity of 15,000 tons.
China News Network says: “The the construction of the lower part of the 'two towers and two anchors' of the Xingkang Bridge was completed at the end of 2016.
The entire structure is expected to be completed by the end of August 2018 while by the end of 2017, the Ya'an to Luding section of the 98 km Expressway will be opened to traffic.
One more step in connecting the plateau to the mainland, while India dreams of a trains to Tawang or Ladakh.
The Long March 1935
The old bridge
The new bridge
 

No comments: