A major challenge in the construction of the Bogibeel rail-cum-road bridge — set to be inaugurated by Prime Minister Narendra Modi on December 25 — was finding the required skilled manpower, and convincing the personnel to work in the hostile conditions of Upper Assam.
“Getting the required manpower on this project in this part of the country, that too ensuring they were technically qualified was a task,” R.V.R Kishore, project director for HCC, the company which built the steel superstructure, told The Hindu. The bridge was under-construction for 16 years.
Over time, they managed to mobilise 120 engineers and 300 welders from different parts of India. The challenge with getting welders was that they had to be qualified as per European codes and welding standards.
Benefiting armed forces
The 4.94-km-long structure, India’s longest rail-cum-road bridge across the Brahmaputra, will help the Indian armed forces move men and material to Arunachal Pradesh in a faster manner. It will also benefit the Indian Railways, as it will help reduce the distance between Assam and Arunachal Pradesh by 600 km.
The design of the ₹4,857 crore bridge is such that, unlike a normal steel bridge, it did not require the use of a single nut or bolt. Bolts and rivets that are normally used in a steel bridge require periodic replacement due to shear failure over traffic loads.
In the Bogibeel bridge, construction of trusses using welding has made the connection between components a permanent one, eliminating the above failures, Mr. Kishore said.
The structure is India’s first fully-welded bridge, which will protect it from harsh weather.
Several companies took part in Bogibeel’s construction. The state-owned RITES undertook pre-construction studies, geo-technical investigations and provided detailed designs. Bhartia Infra constructed the guide bunds and approach embankments.
The foundation and sub-structure were built by Gammon India. A joint venture of HCC, VNR Infrastructures and the German company DSD Bruckenbau constructed the superstructure.
Delivering steel plates
The construction teams used a combination of rail and road transport to deliver 80,000 metric tonnes of steel plates sourced from various parts of the country to the project site in Assam. The orders for extra-wide plates were placed in advance to ensure timely execution of the job. The spherical bearings used in the construction were sourced from Germany, while the load testing of the bearings was done in China. The bearings were then shipped back to the project site after being refitted in Bhopal.
“The high grade, copper bearing steel ensures durability and makes the super structure corrosion proof,” Mr. Kishore said, adding that quality and documentation requirements were really stringent. “A lot of learning has taken place, because this is the first of its kind in India,” he said.
( The writer was in Assam at the invitation of HCC )
