Popularly known as the Rabindra Setu, Howrah Bridge is an engineering marvel and is counted amongst the busiest cantilever bridge in the World. Observing a daily traffic of about 60,000 vehicles and innumerable pedestrians, Howrah bridge have equalled its position to Sydney Harbor Bridge. But the later can never dream of such a traffic. The bridge connects Kolkata and Howrah and is the lifeline of the city. The best way to enjoy its stately beauty is to view it from the middle of the river.
Constructed in 1939 and the bridge was opened to traffic in 1943 which cost as estimated Rs.333 crores, built from 26,500 tons of steel. It is a sort of 'Cantilever bridge'. In it cantilevers project from piers and are connected by girders. Erected during World War II to give Allied troops access to the Burmese front, replacing an earlier pontoon bridge that opened to let river traffic through. The bridge is 705 meters long and 97 feet wide. More than 26,500 MT of high-tensile steel went into this unique bridge supported by two piers, 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. The ferries running from below the Howrah Station another way to cross the river and view the bridge.
Essentially, it had two portions. For the convenient plying of man and traffic, the pool was connected as a whole. However, the bridge was unfastened everyday, particularly during night for steamers, boats and other aquatic vehicles to ply. 
. 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 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.
Considering various aspects like navigational, hydraulics, tidal conditions of the river and the projected traffic conditions, Rendel Palmer & Tritton came up with a design for a cantilever bridge with a 71 foot 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 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 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 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 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 as earthquake and a 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 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 lb per square inch. 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 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 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 Howrah Railway Station is one of the largest in the world with rail connections to all major Indian cities and towns. Howrah Station also serves as an important terminus for the suburban railway services of the Eastern and the South Eastern Railway. Located on the west side of the Hooghly River, it is linked to Kolkata by the Howrah Bridge.