Since the beginning of 21st Century, the challenge was to stop corrosion at the base of the hangers of world’s sixth longest cantilever bridge – Rabindra Setu.
Popularly called Howrah Bridge, it connects Kolkata with its twin city Howrah and withstands a load of 1.10 lakh vehicles a day on weekdays.
In 2001, the Kolkata Port Trust (KoPT), responsible for maintenance of Howrah Bridge, installed hoods at the base of hangers to prevent corrosion by rainwater and seepage water. Six years later, KoPT started a brainstorm to protect the hangers from corrosion due to spitting. In 2011, the port authorities noticed that the 6 mm thick steel plates in the hangers eroded by almost 50 per cent in a span of three years, especially owing to spitting of gutkha extracts.
KoPT has decided to cover the base of the 86 hangers with fibre glass to prevent decay of the steel plate. According to A K Mehra, Chief Engineer, KoPT, this is found to be a solution to the crisis as awareness did not help much in keeping people from spitting on the hangers.
“This will also give us scope for renting out space for advertising on the hangers. And, since fibre glass does not have a retail value, people will not be interested to take them away,” Mehra told reporters here on Thursday.
KoPT will spend nearly Rs 15 lakh to carry out the project.