- Howrah Bridge
The Howrah Bridge is a
bridge that spans theHooghly River inWest Bengal ,India . It was originally named the New Howrah Bridge because it links the city ofHowrah to its twin city,Kolkata (Calcutta). On 14 June 1965 it was renamed Rabindra Setu, afterRabindranath Tagore a great poet and the first Indian Nobel laureate. However it is still popularly known as the Howrah Bridge.The bridge is one of three on the
Hooghly River and is a famous symbol ofKolkata andWest Bengal . Apart from bearing the stormy weather of theBay of Bengal region, it successfully bears the weight of a dailytraffic of approximately 150,000 vehicles and 4,000,000 pedestrians. It is one of the longest bridges of its type in the world.History
By 18th century AD, Calcutta and Howrah on the opposite banks of
Hooghly River had grown up to be the most important economic and cultural centers ofBritish India , and a need for bridging theHooghly River arose. To address this challenge the famous Floating Pontoon Bridge was built in 1874 by Sir Bradford Leslie.The Floating Pontoon Bridge was built using timber on pontoon. The bridge was opened to let river
traffic through. The bridge had hinged shore spans sinceHooghly River is subjected totides . Duringhigh tide s these became very steep and bullock carts were not able to negotiate their way, which resulted in traffic jams. It was also feared that thefloating bridge could affect river currents and causesilt ing problems. With time the bridge became too inadequate for the ever increasing traffic.Due to all these reasons Government of Bengal in 1933 decided to replace the Floating Pontoon Bridge. The Floating Pontoon Bridge which was originally commissioned to service for 25 years, was decommissioned on February 1943, after its long service of 69 years.
Construction of the New Howrah Bridge was started on 1937. The "Cantilever Era" was prevailing at that time, and engineers felts that
cantilever bridge s were more rigid thansuspension bridge s. This bridge is one of the finestcantilever bridge s 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, [http://en.structurae.de/firms/data/index.cfm?ID=f000166 Rendel 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 cantileverfootway s. Considering the quotation from various firms, the contract was awarded to [http://en.structurae.de/firms/data/index.cfm?ID=f000071 Cleveland Bridge & Engineering Co. Ltd] ofDarlington , with a strong recommendation that they use Indian-made steel, which they agreed to do. Out of the total 26,500ton s of steel used, [http://www.tatasteel.com/ Tata Iron and Steel Company] supplied 23,500ton s of steel and fabrication was done by Braithwaite, Burn and Jessop Co. at four different shops in Calcutta.The two huge caissons which was 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
anchor s, grappling irons,cannon s, cannon balls,brass vessels, variety ofcoins . 40 Indian crane drivers were trained on the job and worked in three shifts of 8hour s each. The job 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 asearthquake and aHindu 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 convert|103|ft|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 bar). 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 convert|282|ft|m long and weighing 2,000ton s, were built in December 1941. 16hydraulic jack s, 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 New 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 final cost of the bridge amounted to ₤2,500,000.
Description
The New Howrah Bridge was built between 1937 and 1943 and had a single 450 m span. It is technically a
cantilever truss bridge, constructed entirely byrivet ing, without nuts or bolts. It is currently used as a road bridge, but previously had atram route as well. The bridge also has sister bridges over the river at different points, namely theVidyasagar Setu and theVivekananda Setu .Howrah Bridge is the gateway to Kolkata. Built on the
Hooghly River , its original purpose was to facilitatemilitary transportation between Kolkata and the industrialtown of Howrah duringWorld War II . It remains ancantilever bridge connecting the city to its mainrailway station , theHowrah Station , the one of the busiestrailway station s of the world.The bridge is 705 meters long and convert|97|ft|m wide. More than 26,500 MT of high-tensile
steel went into this unique bridge supported by twopiers , each nearly 90 meters above the road. An engineering marvel, it expands as much as a meter during a summer day. The eight-lane bridge carries a steady flow of approx 150,000 vehicles, 4,000,000 pedestrians and thousands of cattle every day. Its best view is from the middle of the river (butphotography there is prohibited). Theferries running from below the Howrah Station another way to cross the river and view the bridge."Howrah Bridge" was also the title of a 1958
Bollywood film starringMadhubala , andAshok Kumar .Technical details
References
External links
* [http://www.howrahbridgekolkata.nic.in Official Website of Howrah Bridge, maintained by Calcutta Port Trust]
* [http://www.kolkataweb.com/picture/picdisplay.php?id=226 Picture of old Howrah Bridge]
* [http://kulxp.blogspot.com/2006/03/my-kolkata-2.html Photos of Howrah Bridge]
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