Symphony in Steel

A huge Falcon with its wings spread wide, an Eagle chained to its feet or a form of awe, or a Narcissus in love head over heels with his own reflection in the water of the river down below, call whatever you wish, it is Howrah Bridge, renamed as Rabindra Setu, since 1965.

If you ever visit Kolkata and arrive at Howrah Station – one of the gateways to the twin-city – you hardly miss its presence. Come out of the subways or cab-ways and what inevitably catches your attention is the huge steel work of 26,500 mt. The more you watch it from different angles, the more amazed you become. Be it bathed in the golden gleam of the rising sun or in the soft glow of twilight, it stands unique, magnum and majestic.

One of the metaphors of the city, the bridge stands like a doorstep to homes of many. As the homeward people catch sight of the tower of the bridge as tall as 300 ft (92 mt) above ground level, even from miles away, they know they are almost home. A few who cross the river daily, the heritage structure is an essential part of their lives.

The metallic marvel with total length of 2,313 ft stands witness to life both in agony and ecstasy; and has inspired artists to capture its breathtaking view, as set off by the sky, overcast in monsoon or blazing in summer or aquamarine blue in autumn.

an-illustration-of-howrah-bridge

How did it come up?

Historians have it that the bridge happened to be a response to an urgent need, which was to lessen the pressure of traffic across the Hooghly river. With the nineteenth century at its middle, Indian Railways began its run in eastern India (1854). People from rural Bengal came to the city in droves. Crowd in search of fortune in the city swelled soon which rocked boats carrying them across the river. The British rulers realised its impact on trade and formed a committee in 1855-56 to chalk out a plan for a bridge across the river to link Howrah with Calcutta.

It was in 1870 when the Calcutta Port Trust came into being followed by the Howrah Bridge Act passed in 1871. Meanwhile, Sir Bradford Leslie, an engineer of the East Indian Railway, was offered the job of constructing the bridge. As Leslie signed on the dotted line of the contract, a pontoon bridge was brought from England. Assembled in Calcutta by the Port Trust, the bridge was badly damaged by the great cyclone which hit the city on March 20, 1874. Record reveals that a steamer, Egeria, off her moorings rammed headon against the bridge causing severe damage of about 200 ft of the bridge and sinking three pontoons.

The bridge was repaired and opened to public on October 17, 1874. It was in service for 25 years but creaks and whines of the floating bridge, sent an alarm to the authority which prompted them to plan for a new, well constructed modern bridge in 1905. Drawn to the alarm, J. McGlashan, the Chief Engineer of the Port Trust, suggested replacement of the pontoon bridge by a permanent steel structure. Plan was mooted, yet couldn’t be translated into action, as the first Great War (1914-1918) broke out.

Designed by one Mr. Walton of M/s Rendel, Palmer & Triton, the construction of the bridge was all set to begin in 1939, but again the pungent smoke of ammunition and battle cry filled the air, Japan bombed Calcutta on December 5, 1941 – again World War II (1939-1945) intervened. The consignment of 3,000 tons of special steel – required for pins and other non-standard items – which was to arrive from England, was held back considering posterity. However, Tata Steel was asked to supply the remaining 23,000 tons of it. The Tatas developed the special quality of the metal named as Tiscom at their Jamshedpur (Tatanagar) unit. However, the fabrication and erection work was entrusted with the famous Braithwaite Burn & Jessop Construction Company Limited (BBJ), a local engineering firm at Howrah.

The bridge, built at a cost of `25 million, was opened to public on February 3, 1943 with a tram trundling down its traffic way.

the-howrah-bridge

The Technique

While planning, the Port Authorities suggested that installation of foundation columns inside the river channel should be planned effectively so that the siltation pattern of the river and movement of ships remain unaffected. However, it led the engineers to construct the bridge compulsorily with span (the central part of the bridge across the river) at least 1,500 ft to keep the river channel free from any construction of metal structure. This led to the latest technology of bridge construction – balanced cantilever suspension type.

Then the longest span of its type in the world comprising two arms of length 470 ft, each cantilevered from the tower, which in turn support a central suspended girder of 560 ft. The cantilevered arms are held in position by two short anchor spans, held down by massive concrete anchor blocks constructed on either bank. Very few of us would realise that the centre portion is held in its place only with the help of these anchors located 325 ft behind the tower. The deck over which the vehicles cross is a platform hanging from the main bridge truss with the help of steel hangers secured by pins.

It was Shib Banerjee and his firm Hindusthan Construction Co. in Mumbai, that lent the builders their expertise in laying foundation blocks of the bridge at a pressure higher than normal atmospheric pressure, using compressed air.

More than 73 years have rolled away, quiet flows the river under the bridge saluting the men and machines that have toiled tirelessly to present the city with such fascinating and elegant structure.

written by : Partha Mukherjee & Priyanka Mukherjee

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