The Chenab Rail Bridge: An Engineering Marvel of Indian Railway

The place near the Chenab bridge often witnesses hostile weather conditions, and so a sophisticated automatic signaling system installed on both sides will stop the trains from crossing the bridge if wind speeds there touch 90 kph.

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Chenab Rail
Chenab Rail

The Chenab bridge is part of the ambitious 272-km long railway line from Udhampur to Baramulla – named the ‘Udhampur-Srinagar-Baramulla Rail Link Project’ – joining Jammu with the Kashmir valley as an all-weather high-speed alternative. The 272-km long railway line will have 38 tunnels – a total length of 119 km – with the country’s longest tunnel T-49 (12.75 km), and 927 big and small bridges (total length of 13 km) part of it. The place near the Chenab bridge often witnesses hostile weather conditions, and so a sophisticated automatic signaling system installed on both sides will stop the trains from crossing the bridge if wind speeds there touch 90 kph.

For the first time ever since independence, Srinagar will be linked to the rest of India after the overarch deck on the world’s highest single-arch railway bridge over Chenab River will be launched. The world’s highest railway bridge is now being built, and when it is finished, it will be 35 meters higher than the Eiffel Tower.

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. Afcons recently finished the main deck slab concreting of a bridge that is even higher than the Qutub Minar as part of the 16 KRCL bridges project. In under 70 days, four levels of concreting totalling over 1,550 cum were completed. The entire event took place in Jammu and Kashmir’s steep Sangaldan at a height of more than 90 meters above the surrounding countryside.

Construction

The Chenab Rail Bridge was originally intended to be completed in December 2009. However, in September 2008, the project was halted due to fears over the bridge’s stability and safety. Work on the bridge restarted in 2010, with the plan to complete it in 2015.

The design and construction was awarded to Afcons Infrastructure, a part of the Shapoorji Pallonji Group, the third-largest construction group in India, with the help of IISc Bangalore. Major construction decisions were taken by Konkan Railway Corporation. The Defence Research and Development Organisation (DRDO) helped in the design of the bridge, making it blast-proof using special steel.

The erection scheme for the bridge is a project in itself. Two pylons (about 130 m and 100 m high) were erected on either side of the river, and two auxiliary self-propelled cable cranes (capacity of 20 tonnes each) were used to tow temporary auxiliary ropes across these pylons. The ropes were used to support the partly finished arch parts. After arch completion, the trusses will be added, finally the girder will be constructed as a horizontal sliding type platform.

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The bridge, which will include a 14-metre dual carriageway and a 1.2-metre-wide central verge, will have a design speed of around 100 kilometres per hour with a lifespan of 120 years. It is said to be able to withstand earthquakes with a magnitude of up to eight and high-intensity blasts. Steel has been specifically chosen for the construction of the bridge as it will make the project more economical. The metal will also be able to resist temperatures of minus 20 degree Celsius and wind speeds of above 200 kilometre per hour.

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The preparations of the rail link began in 2002 and the initial plan was to connect Kashmir’s northernmost city Baramulla to New Delhi. The project was given high priority by Atal Bihari Vajpayee government but the project suffered several delays owing to the weather conditions and contractual issues. Work on the bridge started again in July 2017 with the aim of completing the construction by the end of 2019 but due to contractual issues in 2018, it was delayed. The coronavirus pandemic also added to the delay in the construction of the project.

Design

After many deliberations, taking into account aesthetics, economy, and availability of local expertise and construction materials, the Chenab Rail Bridge was designed as a large span single arch steel bridge with approach viaducts on either side. The arch is two-ribbed, fabricated from large steel trusses. The chords of the trusses are sealed steel boxes, internally stiffened and filled with concrete to assist in controlling wind-induced forces on the bridge. Another advantage of concrete filling is that internal painting will not be required.

The number of bearings has been minimized, particularly on the approach viaduct, through the use of continuous construction. This is advantageous, as it reduces the maintenance and inspection efforts, and improves the riding quality. The viaduct piers are of concrete, while the piers near the arch are Indian construction standards such as the Indian Railway Standards (IRS), the Indian Road Congress (IRC) and the Indian Standards (IS) were found inadequate for the large spans of the Chenab Bridge.

For example, the Indian Railway Standards (IRS) are primarily intended for simply supported bridges with spans up to 100m (although these have been successfully used for higher spans up to 154m). The spans for the Chenab Rail Bridge greatly exceed this limit, and are continuous. Therefore, to assure a safe design, Indian national standards have been supplemented with International standards such as British Standards (BS), International Union of Railways (UIC), and Euro. Also, many global experts with versatile and relevant experience, have been involved in order to facilitate making the project a success.

Following are some of the design considerations taken into account:

  • Limit state philosophy of design has been decided to be followed as per BS codes
  • Computation of wind load effects as per wind tunnel tests
  • Site specific seismic spectra developed by Indian Institute of Technology (IIT) Roorkee
  • Provision of Euro code 8 for ductility detailing of very tall and hollow rectangular RCC piers
  • Provision of long welded rail (LWR) over the bridges and resulting force calculation as per UIC – 774-3R guidelines
  • Blast resistant design used
  • Design checking for fatigue as per BS codes
  • Deformation limits as per comfort criteria of UIC – 776-2R and UIC 776 -3R guidelines
  • Redundancy provided in the structures, for lower level of operation during mishaps and against collapse in extreme cases of one pier failure

The quality aspect has been emphasised, as the quantum of fabrication and welding is colossal. Mostly indigenous material compliant to IS codes has been planned to be used, whereas for the design, international codes have been referred, which means the Quality Control work is still difficult.

Important Stages & Timeline

  • Dec 2003: Project approved.
  • Feb 2008: Contract awarded for construction.
  • Jul 2017: Construction work resumed on the bridge.
  • Nov 2017: The work bridge’s arch is was expected to be completed By May 2019.
  • Nov 2018: The bridge under active construction.
  • Dec 2018: The project envisaged to be completed by the end of 2019, but ascertained unlikely.
  • Aug 2019: 80% of construction work completed on the bridge, expected to be opened in mid-2020.
  • Nov 2019: 83% work completed on the bridge, expected to be opened in March 2021.
  • Jan 2020: Time for opening again revised. Now expected to be opened in December 2021.
  • Apr 2021: Work on both the ends of the bridge’s arch finally completed. Planned to be opened in 2022.
  • Jun 2022: About 90% of construction work completed, now confirmed to make the bridge operational by December 2022.
  • Aug 2022: The bridge’s remaining work on the final joint completed. The ‘Golden Joint’ of the rail bridge completed on 13 August 2022. The workers decked it with national flag to celebrate ‘Azadi ka Amrit Mahotsav’.

Latest Update

More than 75 per cent of the total 37 bridges and 97.6 per cent tunnelling work on the vital Katra-Banihal railway link stands completed. The Katra-Banihal stretch is part of the prestigious Udhampur-Srinagar-Baramulla Rail Link (USBRL) Project which has missed several deadlines in the past amid huge cost escalations since 1997, when the then Prime Minister H D Deve Gowda laid its foundation at Udhampur. In view of the importance of the USBRL project in providing seamless and hassle-free connectivity, the 272-Km-long railway line project was declared as a ‘national project’ in 2002. While the 161 km was commissioned in phases with first phase 118-km Qazigund-Baramulla section commissioned in October 2009 followed by 18-km Banihal-Qazigund in June 2013 and 25-km Udhampur-Katra in July 2014.

The intervening stretch of the Katra-Banihal section (111 km) is in progress. This is, perhaps, the most difficult new railway line project undertaken in the Indian subcontinent. This section predominantly involves tunnelling of 164 Km (97.57 km main tunnel and 66.4 km of escape tunnel), in addition to construction of 37 bridges on Chenab river and its tributary Anji Khad. At present, 160.52 Km of tunnelling (95.47 km of main tunnel and 65.05 km of escape tunnel) and 28 bridges, out of total 37 have been completed. The work on the project is going on in full swing and the Railways is hopeful about commissioning the final phase to connect Kashmir with the rest of the country next year.

Referring to the completion of the overarch deck of Chenab railway bridge in Reasi district with the laying of the ‘golden joint’ on August 13 as a milestone, the Railways informed that ‘minor’ works on the nearly 1.3 km bridge is expected to be completed by November this year. The paradigmatic bridge is located 359 m above the Chenab riverbed in Kauri village and is 30 m higher than the Eiffel Tower in Paris.

Once completed, the bridge will be able to withstand winds with speed up to 260 kmph and will have a lifespan of 120 years. The project has other firsts like the longest railway tunnel having overall length of 12.75 km situated between Sumber and Arpinchala in Sangaldan area of Ramban district which has been made through on February 15 and first cable-stayed bridge which when completed would be an engineering marvel of 21st century. In addition, a 205-Km access road has also been completed which provides connectivity to far flung and inaccessible remote areas, leading to socio-economic development of the local residents. The cumulative expenditure on Katra-Banihal section up to June is Rs 23,071 crore. The electrification work on the railway line from Banihal to Baramulla also is in progress and is likely to be completed by end of this year.

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