Vidyasagar Setu Bridge also known as the Second Hooghly is a toll bridge over the Hooghly River in West Bengal, India, linking the cities of Kolkata and Howrah. With a total length of 823 metres ,Vidyasagar Setu is the longest cable–stayed bridge in India and one of the longest in Asia. Connecting Howarh and Kolkata, both being one of the most populous places in India, the bridge is designed to carry 85000 vehicles per day.
Vidyasagar Setu is a cable-stayed bridge, with 121 cables in a fan arrangement, built using steel pylons 127.62 metres high. The deck is made of composite steel-reinforced concrete with two carriageways. The total width of the bridge is 35 metres, with 3 lanes in each direction and a 1.2 metres wide footpath on each side. The deck over the main span is 457.20 metres long. The two side spans are supported by parallel wire cables and are 182.88 metres long. The structural steel used in the bridge weighs about 13,200 tonnes. The pylons, which are 128 metres in height, are designed as free standing portals. Pylons are made of 4×4 m steel boxes, expansion joints were provided to allow for 400 millimetres horizontal expansion at the free ends. Fixed end slab seal type expansion joints 115 millimetres were used for horizontal expansion of the joints.
The complete design is first of its kind in India. Usha Martin prepared a complete literature based on the technical requirement of bridge and observations made at site. Using the literature and the technicalities associated with the bridge the company conducted a thorough research before arriving at the specification and design that best fulfills the requirement.