The new Tallah bridge is far from ready and PWD engineers overseeing the project said the structure is unlikely to be opened before June-end.
Officials had earlier said the new bridge would be opened in April.
Engineers supervising the Rs 350-crore project in north Kolkata said only about 40 per cent of the work over railway tracks was over.
“A lot remains to be done before a 240m-long span over the tracks is covered with concrete deck slabs,” said an engineer.
Also, the construction of the two approach roads to the bridge — one from the Shyambazar-end and the other from the Paikpara-end — has not yet started.
