Howrah Bridge to get protective coating against gutka-spit

Howrah Bridge, the 70-year-old landmark that is the gateway between Kolkata and the rest of the country, is getting a fibreglass coating for its vital parts to preserve them from the ubiquitous Indian habit of spitting out globs of saliva laced with 'gutka'.

The dangerous but pervasive tobacco product is corrosive not only internally but externally as well. Gutkha contains slaked lime, catechu (khair or kattha), supari and tobacco. It can corrode the metal as well as the user's insides, authorities in charge of the bridge have found.

The Kolkata Port Trust, which maintains the bridge, told newspersons that a Rs15 lakh project to provide fibreglass covers at the base of the 'hangers' to protect them from the corrosion of tobacco-spitting began on Thursday.

The port trust's chief engineer A K Mehra said studies had found thick layers of gutkha deposits on the covers of hanger bases on either side of the bridge, and tests had shown a severe reduction in thickness of the covers. It was obvious that the corrosion had been caused by chemicals in gutkha, he said.

The superstructure of the bridge is held up on a deck slab by 39 hangers on each side. The hanger bases along the pedestrian walkway have shown the worst corrosion; the authorities have found that constant spitting by gutkha-chewing pedestrians has resulted in the saliva seeping through.

Some 5,00,000 pedestrians are estimated to use the bridge every day.

The KoPT had, in 2007, replaced all hanger base covers (hoods) of the bridge after the steel plates were found to have been eroded considerably. It has now decided to use fibreglass covers, which can be washed and are unattractive to thieves.

Earlier measures to counter the spitting problem, including coating the plates with zinc oxide, had failed.

''We had considered various other materials, including wood. But we thought that if we used fibreglass, it was not likely to be stolen as it has the least resale value. Additionally, fibreglass is washable and easier to keep clean,'' Mehra said.

The bridge, now officially known as Rabindra Setu, was built between 1937 and 1942, and was opened to traffic in February 1943.

According to a study by the transport department of the West Bengal government, in 2007, up to 150,000 vehicles used to pass through the bridge every weekday. The number is likely to have since increased substantially since then.