Guwahati: The commissioning of Bogibeel bridge over the Brahmaputra in Upper Assam, the country's longest rail-cum-road bridge later this year, will make Indian Railways achieve one of its most technically challenging projects.

Comparing it with the "challenging" Chenab bridge in Jammu and Kashmir, the Northeast Frontier Railways (NFR) officials here said for the first time railways have constructed a super-structure in Bogibeel, which is a fully-welded composite Warren-type truss. The steel-and-concrete arch bridge being constructed at 1,178 feet above the Chenab river is another challenging project of the Indian railways.

The bridge has 42 wells, each 2.2-metre thick and the girder has a steel-floor system for railway tracks and concrete for the road.

The design of the composite-welded truss has been done by M/s Ram Boll, Denmark through RITES Ltd (earlier known as Rail India Technical and Economic Service) and the proof-check was done by M/s Anwikar Consultant, Germany. The cost of the super-structure is approximately Rs 1,400 crore (without escalation).

"Constructing a bridge over a river like the Brahmaputra is always very challenging. Although this is the third railway bridge over the Brahmaputra, here our engineers had the added challenge of managing its banks. The hills on the bank of the river helped us construct Saraighat bridge (North Guwahati) and the Naranarayan Setu (Goalpara) but we had to spend a lot of time and confront many technical issues in maintaining the banks before original work of the bridge could be started. This is definitely one of our most technically challenging projects but we hope to achieve it soon," NFR's chief public relations officer Pranav Jyoti Sharma told The Telegraph here.

There are two other road bridges over the Brahmaputra at Amingaon near here and Tinsukia, close to Arunachal Pradesh.

The NFR recently said the bridge, the foundation of which was laid by former Prime Minister Atal Behari Vajpayee on April 22, 2002 and missed several deadlines, will be ready for safety inspection by the second week of October and is likely to be commissioned by the end of this year.

The Assam government will request Prime Minister Narendra Modi to inaugurate the bridge. The bridge will come as succour for people living in Dhemaji and Lakhimpur on the north bank of the Brahmaputra as it will connect them to Dibrugarh town on the south bank by both rail and road.

People on the north bank now either travel by ferry or take the longer road route via Tezpur.

"The bridge will bring relief to people who visit Assam Medical College in Dibrugarh and for other purposes. This will be a huge boost to the country's security infrastructure as our security forces will be able to transport personnel and equipment swiftly to Arunachal Pradesh," Sharma said. Bogibeel bridge was one of the promises in the Assam Accord and was sanctioned in 1997-98. It was declared a national project in 2007.