The foundation work of the two remaining pillars that are coming up on railway land for the proposed Tallah bridge would be completed by April, the state government has decided.

Engineers said completing the foundation work on the eight pillars, including these two, by April would mean inching closer towards the target of finishing the construction of the bridge by 2022.

The railway has agreed to block traffic from midnight till 5am for the entire month of April so that the foundation work of the two pillars can be completed. Machinery and men have also moved in so that the work can be wrapped up by April.

Engineers said these eight pillars on the railway land stand at the centre of the two flanks of the Tallah bridge — one towards Shyambazar-end and the other towards the Dunlop-end — and remain the most crucial part of the construction process. Each of these pillars would stand at least 50 metre underground.

Senior officials from the public works department, the agency that is implementing the Rs 340-crore project, said completing the foundation work of these two pillars would mean crossing one of the biggest hurdles before moving on the second stage of construction.

The proposed Tallah bridge, which will connect large parts of north Calcutta, including Dunlop, Sinthee, Chiria More with Shyambazar, will have two spans on either side of the flat deck in the middle.

These two spans, each measuring about 280 metre, would stand on 12 pillars. The deck in the middle will be about 230 metre long.

“Once the foundation work of these eight pillars is completed, we would reach a landmark of sorts because of the complexities involved. The pillars would come up between railway tracks and will hold the main plank of the bridge,” said a senior PWD official. “The railway has extended full cooperation to us.”

Engineers said meeting the April deadline would be the most vital step towards meeting the next target of completing work by August 2021. “By August we have set a target of completing almost 40 per cent of the construction work,” said a PWD official.