Howrah Bridge ( Rabindra Setu ) : A Gateway to the ‘city of joy’.

Kolkata was declared the capitol of India by the British and so still 1911. The railway station at Howrah set up in the year 1906 and the bridge (later popularly known as Howrah Bridge) thus served as the logistic link with the country’s one of the oldest passed the Howrah Bridge Act, in the year 1871, under the Bengal Act IX of 1871.

Sir Bradford Leslie's famous floating Pontoon Bridge, the earlier avatar of the modern Howrah Bridge, was initially set up in 1874, almost coinciding with the establishment of the port of Calcutta in 1870. For the convenient plying of passenger and vehicular traffic, the pool was connected as a whole. However, this was unfastened everyday, particularly during the night for safe passage of steamers, boats and other marine vehicles. From 19th August, 1879, the bridge was illuminated by fixing electric poles at the centre. This was done by using the electricity rendered from the dynamo at the Mallick Ghat Pumping Station. The Bridge was then 1528 ft. long and 62 ft. wide. On both sides were pavements 7 ft. wide for the sake of pedestrians. The 48 ft. road in between, was for plying of traffic.

The emergence of Kolkata as the political capital of the nation and expanding volume of merchandise routed through the port of Kolkata had a synergistic effect on the commercial importance of the bridge. The location of the initial pontoon bridge, was around 100 yards down-stream of the present Howrah Bridge (renamed as Rabindra Setu in the year 1965) after Rabindranath Tagore, the philosopher - bard and one of the most important nineteenth century renaissance personalities to leave a lasting impression on modern India.

Rabindra Setu is a suspension type balanced cantilever bridge with central span1500 ft. between centers of main towers. The Anchor arms are 325ft. and the Cantilever arms are 468 ft. long at both ends. While the middle suspended span is 564 ft., main towers are 280 ft. high above the monoliths and 76 ft. apart at the top Bridge deck width is 71 ft. with two footpaths of 15 ft. on either side.

All members of the super structure comprise built-up reverted sections with a combination of high tensile and mild steel. Between towers, bridge deck hangs from panel points in the lower chord of the main trusses with a series of hangers (39 pairs). Roadway beyond the towers is supported on ground leaving anchor arm free from deck loads. Bridge deck comprises 71 ft. carriageway and 15 ft. footway, projecting either side of the trusses and braced by longitudinal fascia girder.

Construction of the New Howrah Bridge was started on 1937. The Cantilever Era was prevailing at that time, and engineer’s felts that cantilever bridges were more rigid than suspension bridges. This bridge is one of the finest cantilever bridges in the world - left to India by the British engineers.

Considering various aspects like navigational, hydraulics, tidal conditions of the river and the projected traffic conditions, Rendell Palmer & Tritton came up with a design for a cantilever bridge of 1500 feet, with a 71 feet wide roadway and two 15 feet wide cantilever footways. Considering the quotation from various firms, the contract was awarded to Cleveland Bridge & Engineering Co. Ltd of Darlington, with a strong recommendation that they use Indian-made steel, which they agreed to do. Out of the total 26,500 tons of steel used, Tata Iron and Steel Company supplied 23,500 tons of steel and fabrication was done by Braithwaite, Burn and Jessop Co. at four different shops in Calcutta.

The two huge caissons which were sunk (on the first stage of construction) is still the biggest ever sunk caisson on land. It is told that while clearing the muck, all kinds of curious things was brought up, which included anchors, grappling irons, cannons, cannon balls, brass vessels, variety of coins. 40 Indian crane drivers were trained on the job and worked in three shifts of 8 hours each. The jobs of sinking the caisson were carried out round-the-clock at a rate of a foot or more per day.

One night, while grabbing out the muck to enable the caisson to move, the ground below it yielded and the entire mass plunged down two feet, shaking the ground. The impact of this shake was so intense that the seismograph at Khidirpore had registered as earthquake and a Hindu temple on the shore was destroyed; which was subsequently rebuilt. In spite of these challenging situations the caissons were placed true to position.

To keep the water out at depth of 103 feet (31 m) around the foundations so that construction can be done, around 500 people were employed on the compressed air operation. The air pressure maintained was about 40 lbs per square inch (2.8 bars). The work on the foundation was completed on November 1938. By the end of 1940 the erection of the cantilever arms was commenced and was completed in mid-summer of 1941. The two halves of the suspended span, each 282 feet (86 m) long and weighing 2,000 tons were built in December 1941. 16 hydraulic jacks, each of 800 ton capacity were pressed in to service for joining the two halves of the suspended span.

After completing the steel work of the deck and concreting of roadway. The Howrah Bridge was finally opened to traffic on February 1943. The old Floating Pontoon Bridge was decommissioned. In May 1946, census of the daily traffic on the bridge was taken and it was found to be 27,400 vehicles, 121,100 pedestrians and 2,997 cattle. The rate of only vehicle traffic over the bridge was 20% more than that on the London Bridge, in the same period, which was till then the busiest bridge in the metropolis.

The eight-lane bridge carries a steady flow of more than lakh vehicles and 2 million commuters every day. The best way to enjoy its stately beauty is to view it from the middle of the river where photography is strictly prohibited. The ferries running from below Howrah Station are a more convenient way to cross the river and give a good view of the bridge.