The final piece of the overarch deck at the world’s highest single-arch railway bridge, in Jammu and Kashmir, will be launched on August 13. The moment will be marked with a golden joint.
The bridge superstructure on the arch was being incrementally pushed from two ends of the Chenab River valley, and it will finally meet at the middle of the arch. “Once the golden joint is completed we can safely say that the bridge is about 98% complete," said Giridhar Rajagopalan, Deputy Managing Director of Afcons.
An iconic bridge that involved complex engineering, Chenab Bridge faced multiple obstacles. Starting from the geology, the terrain and the hostile climate, the engineers and railway officials have faced it all to come to this moment.
“When we finished the arch closure last year, it gave us huge relief in terms of our competency to finish the project with such accuracy that there was no mismatch. And that gave us a lot of confidence to tackle the balance part of the project very comfortably. Together with NR and KRCL, we are eagerly looking forward to the forthcoming milestone of the golden joint,” Giridhar added.
There are plenty of firsts in the construction of the world’s highest railway bridge, and once completed, it will stand 35m higher than the Eiffel Tower. Besides the Chenab Bridge, Afcons is also constructing 16 other railway bridges for Konkan Railway Corporation Limited (KRCL) in the hostile terrains of Jammu and Kashmir. All the bridges are part of the Udhampur Srinagar Baramulla Rail Link (USBRL) project.
Afcons recently completed the main deck slab concreting of a bridge in the 16 KRCL bridges project that is even higher than the Qutub Minar. Around 1,550 cum of concreting was done across four stages within 70 days. The entire activity took place at a height of over 90m from ground level in the hilly terrain of Sangaldan, in Jammu and Kashmir.
In the Chenab Bridge, 93 deck segments, each weighing about 85T, have been simultaneously launched from both ends of the valley over the mighty steel arch and five are in progress. Both ends will finally meet to complete the bridge overarch deck and the segments will be joined with the help of High Strength Friction Grip (HSFG) bolts to mark the golden joint. This will complete the bridge over the Chenab river valley.
Around 30,350 MT of steel has been used in the 1315m long Chenab Railway Bridge construction. 10,620 MT of steel has been consumed in the construction of the gigantic arch, and 14,504 MT of steel has gone into the construction of the bridge deck. The bridge, on the upstream of Salal Dam, is situated near Kauri village in the Reasi district of Jammu and Kashmir. The bridge is being constructed by Mumbai-based infrastructure major Afcons, keeping safety, quality and productivity as their main driving parameters.
“For the first time in Indian Railways, incremental launching was done on transition curve and a longitudinal gradient, both occurring at the same location, for the deck launching of the viaduct portion of the Chenab Bridge. Typically, bridges have been constructed incrementally on a straight or a curved platform with a uniform radius. Executing launching activities in inclement weather & stormy wind conditions was extremely challenging,” Giridhar said.
Both Northern Railways (NR) and Konkan Railway Corporation Limited (KRCL) had played a huge role in finalising the design of the iconic Chenab Bridge. Reflecting on their involvement at crucial stages of the bridge construction, Giridhar said, “We received tremendous support for any technical issue, approval for drawings, method statements, and most importantly, both NR and KRCL played an important role in generating local employment. KRCL constructed all the access roads to the project site. These roads have provided connectivity to far-flung villages in the region.”
“The Northern Railways allowed us to use the Phased Array Ultrasonic Testing Machine for inspection of welds. This was done for the first time in India,” he added.
The fabrication was carried out in sophisticated workshops set up at both ends of the bridge. The heavy and bulky segments were transported to the launching pad with the help of SPMT, a specialised modular trailer. “Considering the treacherous hilly terrain, a temporary launching platform with a segment lifting capacity of 120 MT & for a height of about 39m was designed. We developed and implemented several innovative methods to overcome the challenges of the hilly terrain for successfully executing our launching activities,” Giridhar said.
For the first time in India, a fully equipped NABL laboratory was set up to ensure that quality was being monitored at every stage of the project. “The Northern Railways supported us in setting up the NABL lab at the site for conducting weld sample tests. This saved a lot of time,” he added.
With KRCL’s support, Afcons could carry out mock-ups of all main bridge components before executing the original work which gave confidence to the engineers. This was super critical in ensuring the quality and safety of staff and workers.
Once completed, the Chenab Railway Bridge will be 35m higher than the Eiffel Tower.
Besides completing the world’s highest single-arch railway bridge in Jammu and Kashmir, Afcons also holds the distinction of refurbishing Bihar’s iconic Mahatma Gandhi Setu and converting it into India’s longest steel bridge.