As evening turns into night in Kolkata, a streak of light dashes across the Hooghly river, connecting the West Bengal capital to the industrial city of Howrah. The lights mark the length of the Vidyasagar Setu, India’s longest cable-stayed bridge and one of modern Kolkata’s defining structures. It was inaugurated on October 10, 1992 - more than 13 years after the actual construction work began.
The history of modern bridges in Calcutta goes back to the years just before the 1857 revolt, when the British appointed a committee to consider ways to deal with the rush over the Hooghly. The plan finally took off in 1868, and in a couple of years the Calcutta Port Trust was founded.
This eventually led to the building of a pontoon bridge, but looking at the increase in traffic, the authorities decided to build a better, stronger bridge. Accordingly, the New Howrah Bridge Commission was set up in 1922, the New Howrah Bridge Act passed in 1926, and the Goode Committee formed in 1930. The committee’s brief was to examine the feasibility of a pier bridge between Calcutta and Howrah.
Eventually, the British firm Cleveland Bridge & Engineering Company got the contract and the construction of the first Howrah bridge began. The construction of cantilevered arms finished in 1941.
Calcutta soon got a famous landmark. But with the population and industrialisation accelerating in independent India as the years rolled by, even the mighty Howrah Bridge was proving increasingly inadequate to cater to the growing congestion.
The Hooghly River Bridge Commissioners, a statutory body now under the West Bengal Transport Department, was established in 1969 for construction of the Vidyasagar Setu.
In May 1972 Prime Minister Indira Gandhi laid the foundation stone of the Vidyasagar Setu, so named after the 19th-Century Bengali intellectual and reformer Pandit Ishwar Chandra Vidyasagar. It would be another two decades before the bridge, a joint public-private sector initiative, would become a reality. The 823-metre-long bridge was built at a cost of nearly Rs. 4 billion (Rs. 400 crore).
With 121 cables in a fan arrangement made of steel pylons and a deck of composite steel-reinforced concrete with two carriageways, the bridge has a width of 35 metres. There are 3 lanes on both sides, and a 1.2-metre-wide footpath on each side. Vidyasagar Setu can handle as many as 85,000 vehicles in a day, much more than the daily traffic of today. Designed by Schlaich Bergermann & Partner, the bridge was constructed by a consortium of Braithwaite, Burn and Jessop.
Three other bridges on the Hooghly link Kolkata to Howrah district: Vivekananda Setu, Howrah Bridge (officially called Rabindra Setu), and the most recent, Nivedita Setu.
The design of the Second Hooghly Bridge, as Vidyasagar Setu is popularly known, is based on the concept of dead load: the deck is designed with a grid structure, with one group of girders at the end and another in the middle. The structural steel used in the bridge weighs more than 13,000 tonnes. The 128-metre-high pylons work as free-standing portals and have two cross-portal members at the bottom and top, below the pylon head. Cables were erected from pylon heads using 32 MT hoist frames mounted on top of each pylon. Lifting was done with the help of sheave blocks, winches and snatch blocks.
Worryingly, accidents are not uncommon on the bridge. Besides loss of life and property, they also lead to traffic snarls. To tackle traffic rush at the entry point, the Hooghly River Bridge Commissioners is working on solutions such as building exit and entry ramps and improving lighting.
Traffic projections for the bridge have been below par. According to a survey in June, in one particular week, fewer than 30,000 vehicles crossed the bridge as opposed to the projected estimate of 85,000.
The first detailed inspection of Vidyasagar Setu was conducted in August 2013 by a team that included experts from Schlaich Bergermann and Partner, the German firm that designed the bridge. Among other aspects, the bridge’s carriageway, underbelly, foundation pillars and bearings were examined. "We have recommended changing the bearings as part of maintenance," a member of the team conducting the survey said. Though annual maintenance is an ongoing process, the comprehensive survey was carried out after experts reportedly suggested that the cables needed to be closely examined as it was important to check the anti-corrosive material in them.
These and other challenges are, however, manageable. Residents of Kolkata and Howrah are justifiably proud of the Vidyasagar Setu, which has found its place on the cinematic screen as well, with scenes from several films shot here. In a changing Kolkata, the Second Hooghly Bridge will continue to remain an important engineering and aesthetic addition to the city’s architecture and landscape.
Also on this day:
1906: R. K. Narayan, Indian writer and leading figure of early Indian literature in English, was born
1954: Rekha, Hindi film star, was born
1964: Guru Dutt, iconic film director and actor, died
1992: Bharat Bhushan, Bollywood actor, passed away
2011: Jagjit Singh, Ghazal legend, passed away