JYOTI SHARMA
REASI, AUGUST 13:
Moving closer to providing an all weather rail connectivity between Kashmir and rest of India, Chairman and MD of the Konkan Railways, Sanjay Gupta on Saturday unveiled the “golden joint’’ connecting two ends of the overarch deck of the world’s highest railway bridge over Chenab in Reasi district of Jammu and Kashmir.
The occasion was marked with the bursting of firecrackers and waiving of national flags amidst singing of national anthem and chanting of Bharat Mata Ki Jai by engineers and workers hailing from different parts of the country.
“This is a historic moment,” Sanjay Gupta said, adding that the term ‘golden joint’ was coined by the civil engineers on worked on connecting the two ends of the deck of the bridge.
The Union Minister Ashwini Vaishnav took to Twitter to showcase a video of the launch of the Golden Joint and the deck closure ceremony from the Chenab bridge. The 40-second video added in the tweet shows the workers celebrating atop the world’s highest bridge as they have worked tirelessly for years to achieve this feat.
Since this is a railway bridge, the next task will be to lay the railway tracks on the bridge, an engineer present at the site said, adding the task of laying the tracks will begin soon as the engineers have already begun constructing the platform for the tracks.
Constructed for Konkan Railways by Afcons at the cost of Rs 1,250 crore, the 1.3 km long highest railway bridge is 359 m above the Chenab riverbed and it is 30 m higher than Eiffel Tower in Paris. It will provide all weather rail connectivity to Kashmir with rest of the country.
At present, Kashmir has only truncated railway line between Ramban district’s Banihal area of Jammu province to Baramulla in the Valley.
The highest single-arch railway bridge in the world — is a unique example in modern engineering, has been constructed by Mumbai-based infrastructure major Afcons and it is part of the ambitious Udhampur-Srinagar-Baramulla rail link (USBRL) project carried out by Northern Railways at an estimated cost of Rs 28,000 crore.
Afcons is building 16 additional railway bridges for Konkan Railway Corporation Limited (KRCL) in the dangerous terrain of Jammu and Kashmir in addition to the Chenab Bridge. All the bridges are part of the Udhampur-Srinagar-Baramulla Rail Link (USBRL) project.
The Indian Railways has undertaken a mega project of Uddhampur-Srinagar-Baramulla Rail Link (USBRL) providing all weather connectivity to people of Kashmir with rest of India.
With the completion of the joint, the Bakkal and Kouri sides of the bridge will be embraced with each other opening a new chapter in the connectivity between them, said Surinder Mahi, Chief Administrative Offier of the Udhampur-Srinagar-Baramulla Railways. By providing direct rail link between Jammu and Kashmir with the entire mainland of India, the project is going to be a game changer in socio-economic upliftment of the Union Territory, he added.
Chenab Bridge with intricate engineering, the harsh terrain, and the hostile environment is a unique example of modern engineering. Among factors like viability, aesthetics, innovation, technology and geography that invoke awe and fear for the mega project, the most potent one is the risk to human life. Few would dare to imagine venture into, let alone work, at such impossible heights, battling extreme winters, torrential rains and excruciating summers. But Afcons’ engineers have overcome the odds, a senior officer said.
While everything about the Chenab Railway Bridge project is extreme and unique in nature, besides being critical due to its intricate design and geometry, the erection of the mammoth segments of arch erection weighing 34 MT was done with the help of world’s tallest cable crane.
The bridge with main arch span of 467 mts and having a steel fabrication of approximately 28,660 MT has been designed to withstand wind up to 100 kmph. Its other unique features include use of concrete filled trusses and power operated cars for inspection and maintenance of bridge for the first time in India; world’s one of the longest cable crane assembly used for erection of steel members of bridge and it is designed to bear earthquake forces of zone V.
The Ministry of Railways had sanctioned the project from Udhampur-Srinagar-Baramulla in phases which include Udhampur to Katra (25km) stretch in 1995; Quazigund to Baramulla (118km) in 1999 and Katra to Quazigund (129km) in 1999. It was declared as National Project in 2002.
Apart from this Chenab bridge, Afcons is building 16 additional railway bridges for Konkan Railway Corporation Limited (KRCL) in the difficult terrain of Jammu and Kashmir. All the bridges are part of the Udhampur-Srinagar-Baramulla rail link project.
Some of the challenges involved in contruction of the bridge included dependence of cable crane are as follows:
Dependency on Cable Crane: The cable crane is the backbone, and, the only source of erection activity in the project due to its location and height. Cable crane operations, however, get impacted due to heavy rains, gale-force winds, thunderstorm and lightning which affect arch-erection productivity. So, proper planning and time-bound activity is of utmost importance
Alignment of Erected Segments: Alignment of arch segments is very important for controlling geometry of the arch. This involves meticulous and regular survey during erection of arch segments. Temperature and wind-monitoring are crucial during erection and survey. Surveys are done early in the morning to avoid temperature variation. Arch-erection cannot be done if wind speed exceeds 15 metres per second
Unpredictable Weather: Due to unpredictable climate at a higher altitude, the arch-erection activity is always fraught with dangers. To mitigate the risk, adequate safety measures are adopted with additional activity time accounted for each arch-erection. The hostile climate is a clear and present danger for engineers
Erection of Temporary Structures: Besides arch-erection, time-taking activities like frequent shifting of platform for each erected segment, and, providing scaffolding arrangement for bolting and torquing are repetitive events for every arch erected
Transportation of Wind Bracings: Transportation and shifting of wind bracing to erection location is a challenging task due to its length and weight. The uneven mountainous terrain makes transportation of the wind bracings extremely difficult
Erection of Wind Bracing: Before erection of wind bracing, platforms must be provided at the location for ease of erection with proper safety measures. Pre-assembly must be done with required degree of inclination to erect as per the required geometry. Accordingly, arrangements must be made for lifting of wind bracings. After erection, in-situ welding is done at required locations which is a difficult activity under windy conditions
Trial Assembly of Arch Segments: Before arch-erection, the geometry (stress less) at ground level is checked so that any modification, or, alteration can be done on ground before erection. It’s extremely difficult and risky to rectify errors at such precarious heights after erection
Erection of Split Segments in Multiple Lifts: Erection of such segments is one of the most difficult tasks due to involvement of multiple arrangements which includes platform erection and lifting arrangements. Due to eccentricity in loading of split segment, special lifting arrangements must be made
Torquing of HSFG Bolts: Torquing plays a vital role in erection of arch. Shifting of equipment for torquing at such height and location is challenging and consumes time. Working at such elevations is very risky and needs specialised teams and platforms with safety measures in place. It is impossible to retrieve any HSFG bolt if it unfortunately slips and falls into the river from such height
Stay Cable to Hold Cantilever Arch: The stay cable is a vital part of arch erection. Stay cables are used for controlling the arch erection activity by using temporary steel piers (erected on permanent piers) and foundation on both sides of the valley. This is done for the first time in Afcons.
