Vivekananda Bridge is a major steel bridge over the River Hooghly and is one of the first rail-cum-road bridges in colonial India. It serves as an important link between Calcutta and the rest of India through Bally, impacting passenger commuting, as well as regional trade and commerce. The bridge has seven main spans of 107 m each, supported on brick masonry piers founded on caissons. These spans are made of riveted steel members weighing about 2500 t each, 70% of which was produced indigenously. The main spans are modified Petit-type steel trusses placed at 11.6 m between the centre of booms. The total width of the bridge is about 30 m with the dual-track railway line in the middle, flanked by roadways and footpaths on both sides. The cross girders are suspended below the two bottom booms, and cantilever extensions of these cross girders carry the roadways and footpaths. Although planning for the bridge was mooted in 1912, it was not until January 1927 that the work at the site was started. The bridge was finally opened to traffic in December 1931 by the then Viceroy, Earl of Willingdon and was earlier called after him as Willingdon Bridge (also later known as Bally Bridge).