Braithwaite Rail-Cum-Road Bridge Over Brahmaputra

Braithwaite Burn & Jessop Construction Co Ltd (BBJ), a subsidiary of Bharat Bhari Udyog Nigam Ltd (BBUNL), is building another rail-cum-road bridge over the Brahmaputra river. The bridge, claimed to be the longest will join the two districts of Bongaigaon and Goalpara in Assam.

Earlier, the company had built the second Hooghly bridge -Vidyasagar setu, one of the longest cable-stayed bridges in the world.

The 2.5 km long steel superstructure called Naranarayan setu is set to be completed by September this year resting aside efficacy claims of using pre-stressed concrete superstructure for railway bridges.

The road-cum-rail bridge involved 30,000 million tonnes of steelwork and can accommodate the heaviest type of loading on rail track and roadway.

 

The steel, source said, was indigenously procured from the Steel Authority of India Ltd (SAIL), contrary to the cost-effectiveness claims of pre-stressed concrete bridge.

The pre-stressed concrete bridge lobbyists argue that steel used to make bridges has to be imported while pre-stressed concrete bridges have no import content.

However, Naranarayan setu is a case in point for which the steel was indigenously procured.

Besides, experts refuse to accept claims that concrete bridges have no maintenance costs. Sources point out that maintenance cost in case of concrete bridges are higher than that of the costs borne for maintenance of steel superstructures.

Concrete is a porous material and water percolates through concrete structure very easily. Thus in the long run the re-inforcements of the bridges get rusted inside.

Periodic maintenance is required to check the re-inforcements, experts point out. The re-inforcements are treated with anti-corrosive treatment with phosphating and this attracts huge costs, sources said. However, in steel bridges, visual checking can detect faults and hence maintenance costs can be minimised.