The state government has requested Schlaich Bergermann Partner, the German company which designed Vidyasagar Setu, to oversee the ongoing repair work.
Inaugurated on October 10, 1992, Jörg Schlaich and Rudolf Bergermann from the Germany company were responsible for the design of the bridge.
“We have asked the company to send a team of experts to examine the ongoing repair work to ensure there were no glitches. The bridge’s design is very complex and we don’t want to go wrong at any step,” said an official of the Hooghly River Bridge Commissioners, which maintains the structure.
The second Hooghly bridge is built with 152 cables in a fan arrangement using steel pylons. There are two sets of pylons at two ends with their foundations underwater that hold the cables on the top.
Besides the 152 “stay cables” another set of 16 “holding down cables” ensure the cables above can hold the tension of the entire bridge structure and the deck remains stable to bear the vehicular load.
“A set of holding down cables have been successfully replaced within a month since the repair started in December. We will now proceed for the second set,” the official said.
“We have set a deadline of end-March to complete the work so that one of the lanes of the bridge’s Howrah-bound flank that now remains shut to traffic is thrown open.”
The Rs 200 crore-project involves replacing several stay cables on the top of the bridge, carrying out magnetic resonance examination of the remaining cables and replacing around 20 bridge bearings and the holding down cables.
“Separate companies are working on different parts of the bridge’s maintenance because the design is quite complex and the repair is a very precise job,” said an engineer of the public works department (PWD).
“We want the experts from Schlaich Bergermann Partner to examine each segments that comprise the whole repair and maintenance of the bridge.”
Engineers said once the work beneath the Howrah-bound flank of the bridge is completed, they will meet Kolkata police and its counterpart in Howrah to decide when the city-bound flank can be taken up for repair work.
“We will need four months of closure of one of the three lanes on the city-bound flank to wrap up the maintenance work. Unless the police agree, it won’t be possible to take up the work on the other flank,” said the official.
Police officers said the traffic diversion plan for one of the lanes shut to traffic had been fine-tuned to ensure goods vehicles remained off the structure.
“We will need to draw up a diversion plan again for the other lane,” said the officer.