The East-West Metro has suffered a substantial delay in completion owing to three accidents during tunneling work at Bowbazar in central Kolkata over the last three years.

"Commercial services are most likely to start before the end of this year between New Garia and Ruby Crossing, and Joka-Taratala," the Metro Railway official told PTI. The Joka-Esplanade Line, which suffered a severe delay in completion, will have truncated services in the first phase between Joka and Taratala, he said.

The trial run between Joka and Taratala started in September, and following necessary clearance from the Commissioner of Railway Safety (CRS), commercial services will commence.

CRS inspection is yet to be held for the 6.2-km route New Garia and Ruby Crossing stretch of the New Garia-Airport Line, the trial run for which was also held in September, sources said.

The East-West Metro's full route covering 16.6 km, connecting Sector V in Salt Lake with Howrah Maidan, is likely to be completed between June and August next year, if there is no major impediment any further, the official said. "As of date, our target is to start the service by August 2023, it may start even earlier," the official said.

On August 31, 2019, a tunnel boring machine (TBM) had hit an aquifer leading to severe ground subsidence and the collapse of several buildings at Bowbazar. At least three houses were damaged again in May this year owing to ground subsidence caused by water seepage during work for joining the tunnels coming from the Sealdah side in the east and the Esplanade side on the west.

At least 12 houses developed cracks again in October at Bowbazar following water seepage during work in the underground tunnel. The East-West corridor is partially operational between Sector V station and Sealdah. Out of the 16.6 km length of the East-West metro, the underground corridor constitutes 10.8 km between Howrah and Phoolbagan with the tunnel passing below the Hooghly river, while the rest is elevated.

(With PTI inputs)