Barak: a bridge that begs for attention

July 16: A scenic bridge across the mighty Barak river on the eastern fringe of Silchar, which connects the town with the lone airport in south Assam, Lakhipur subdivision in Cachar district and the adjacent state of Manipur, is tottering at the edges.
The landmark bridge, according to the civil engineers in the PWD department, is now gasping for stability, having developed considerable weakness in its middle, where the two ends of the cantilever meet.
This 472-metre-long bridge has a width of 7.5metres and was constructed by Gammon India Ltd and Sharma and Sons. It was opened to traffic during the devastating floods that swept through Cachar in 1966.
On an average, over 500 vehicles of different kinds ply on the bridge every hour. But this mammoth structure, certified to last for 100 years by its builders, suddenly started experiencing “fatigue” in 1999.
Engineers in the national highway division of the state PWD found, much to their consternation, that the two ends had developed considerable weakness, thus making the bridge hazardous for vehicular movement.
An expert team of engineers of the Union ministry of national highways and transport flew down to Silchar for a spot inspection of the bridge in June 2000.
After a series of parleys with the local PWD engineers, it decided to install a flyover made of steel and timber below the surface of the bridge in its middle to give it balance and add to its strength and resilience.
“We have already sent an alert to the Union national highways ministry. The ball is now in their court. However, there is no chance of the bridge collapsing and falling down,” Matiur Rahaman Lasker, the executive engineer in-charge of the national highway division of the Barak bridge, said.
The flyover has so far endured the slow hammering action on the hinge joints of the cantilever.
The cantilever method is a long projecting beam, which remains fixed at its ends. As soon as passing vehicles exert pressure on the cantilever system of the bridge, its two ends expand and get hooked to provide the required balance.
During repairs, a device named Exjomet C-160 was also used in the middle of the bridge where the flyover was set up with a view to replacing the distressed old conventional joints.
But as the convulsions intensified, the engineers mooted the idea of yet another round of joint survey of this bridge.
The bridge has also lost its sheen. The macadamised portions have become worn out, and hence motorists and commuters are now required to negotiate the travails of travel whenever they venture on this bridge.