Chenab Bridge – World’s Highest Railway Bridge
Touted as the man-made wonder, the world’s highest rail Bridge is being built across Chenab River in Rasai district of Jammu and Kashmir, India. The bridge costing INR 512 crores is a part of Jammu-Udhampur-Srinagar-Baramulla Rail Line (JUSBRL) project being undertaken by Ministry of Indian Railways.
Located in a high seismic zone and a terror-prone area, barely 50 kms from LOC, the project was scrapped in 2008 because 6 years after starting the project, the contractors couldn’t even lay the foundation of the bridge on the landslide slopes of a deep Himalayan gorge. However, 9 months after the railway board scrapped the plan to build the world’s highest bridge on Chenab an expert committee has cleared the way for its revival.
The Chenab Bridge is a steel railway arch bridge with a total length of 1315 meters. The bridge consists of an approach bridge that is 530 meters long, an arch bridge that is 785 meters long. A 469 meters long steel arch supports the steel deck. In arch portion, the superstructure is supported on steel piers with a height of up to 120 meters. The deck of the bridge is 13.5 meters wide and has 2 railway tracks running on it.
The bridge which is situated about 359 meters (35 meters higher than Eiffel Tower) above bed level of Chenab, posed big challenge in design and construction. The weather in the region gets worse in no time due to Himalayan range and at this height strong wind blowing at 220 kmph posed problems not only to the stability of the bridge but also to shape of bridge which necessitated special considerations in the design. Engineers decided that the only bridge type suitable for the location would be a massive steel arch. Only an arch is capable of handling the weight of a 300-ton locomotive along with thousand tons of passenger rakes. With the length of 469 meters, the main span will rank among the world’s 10 longest arches.
Finland based WSP Consulting KORTES Ltd has the main responsibility of planning of the bridge and the design of steel arch is done by sub consultant Leonhardt, Andra und Partner of Germany. Chenab Bridge forms a massive arch, the first of its kind in India and one of the longest in the world. The design speed of railway is set to 100 kmph and the design life of the bridge is 120 years.
The deck of the bridge is partly in straight horizon and partly in curves. It is located on a transition curve with changing radius. The construction is therefore carried out in stages following gradual change in the alignment; it is for the first time bridge is constructed incrementally on a transition curve. Bridge required approximately 25000 MT of structural steel, 4000 MT of reinforced steel and 46000 m3 of concrete. Steel was chosen to construct the bridge as it will be more economical and will able to resist temperature in the range of -20 C and wind speed of above 200 kmph. Since J & K region has witnessed frequent terrorist attacks the bridge is constructed in 63 mm thick special blast-proof steel. The concrete piers of the bridge are designed to withstand explosions. A ring of aerial security, online warnings and monitoring systems on the bridge will be provided to safeguard the bridge.
The construction of the bridge has many challenges. The steel structures of the bridge are manufactured in workshops built in mountains. The workshops and paint shops are moved to site because there is no proper road network. The largest building parts that can be delivered to the site are 12 meters in length. The insufficient infrastructure caused additional problems.
There is no electricity and the water of the river is unsuitable for manufacturing concrete. Therefore, all electricity is produced at site and water is delivered to site from far away sources located in mountains.
The Kashmir valley has always been one of the most isolated regions in India. When the rail line finally gets finished, it will once and for all open up the Kashmir Valley area to the rest of India and the outside world.