GUWAHATI: The Northeast Frontier Railway's (NFR) construction organization has started constructing a bridge, which is slated to be the world's tallest after completion, at Noney in Manipur.

Senior PRO (Construction) of NFR D Borah said, "This bridge near Noney in Manipur has a height of pillars rising up to 141 metres. This bridge is slated to become the tallest in the world from the point of view of pillar height surpassing the existing tallest of Mala-Rijeka viaduct on Belgrade-Bar railway line in Europe where the height of pillars is 139 meters."

He added that another under-construction railway bridge is coming up on the Chenab in Jammu-Kashmir, bridging a gorge of about 360 meters deep from the bed of the river to the rail level. It is considered as the highest railway bridge in the world.

The proposed bridge in Manipur is part of the 111-km-long Jiribam-Tupul-Imphal railway line to connect the capital of Manipur with the broad gauge network of the country. The alignment of the railway line passes through steep rolling hills of the Patkai region, eastern trail of the Himalayas. While Jiribam, a small town of Manipur near the Assam?Manipur border is situated at 37m above mean sea level, the capital city Imphal is situated at 780m above mean sea level.

The alignment has to traverse through a number of deep gorges and over several rivers flowing at low ground levels. As a result, it has been necessary to construct 46 tunnels measuring a total of 54.5 Km in length and tall bridges to maintain a suitable gradient for efficient operation of railway services. The longest tunnel will be 4.9-km-long between Jiribam & Tupul and 10.75 km between Tupul & Imphal.

While the high mountains are penetrated by constructing tunnels, the deep river gorges between the mountain ridges are connected by tall bridges. "The railways had constituted an expert group to study the possible alternative span arrangements of such tall bridges, considering the parameters like the length of span, type of span, location of the piers, constructability, serviceability, geological features, possible tectonic and movement. Based on the recommendations of the expert group, it was decided that the main superstructures will be of steel open web through type girders of 103.5m span (centre to centre of bearings). The pillars are of reinforced cement concrete hollow type with the tallest pillar being 141m high. The height of other piers of this bridge varies from 50m to 90m," said Borah.

