The construction of the base walls around a shaft in central Kolkata’s Bowbazar is underway, said officials of East-West Metro.
The construction of a concrete base slab, the key to bridging a gap at the Metro site in Bowbazar but stalled since the subsidence on May 11 last year, began in the third week of February this year and was completed on March 3.
The construction of the sidewalls and the roof are the remaining steps before the gap is shut. The closure of the shaft — made to retrieve the twin tunnel boring machines — is a must to bring trains from Sealdah, through the Sector V-bound tunnel, for trial runs between Esplanade and Howrah Maidan.
“The construction of the sidewalls has begun. Around two metres of construction is complete. The walls will scale up to around nine metres. Once the walls are constructed, we will start building the roof. There are some bracings which had been installed as supporting structures after the subsidence (on May 11, 2022). The bracings will also have to be removed,” said an engineer of the Kolkata Metro Rail Corporation, the implementing agency of the East-West Metro project, which, once fully operational, will link Howrah Maidan and Salt Lake Sector V. The full 16.5km corridor includes a stretch under the Hooghly.
Now, the corridor sees commercial runs on a truncated section between Sector V and Sealdah. The section between Howrah Maidan and Esplanade is nearing completion and gearing up for commercial runs by the end of this year, according to Metro officials.
Trial runs are imperative before commercial runs and that is why the closure of the shaft at Bowbazar is important.
At a news conference on March 6, the managing director of KMRC had ruled out the possibility of linking the 2.5km stretch between Esplanade and Sealdah by this year-end. But he also promised to make the section between Howrah Maidan and Esplanade ready for commercial runs by 2023. The bracings in the Bowbazar retrieval shaft are not the only support structures that need to be removed before arake can be brought to Esplanade.
“Tracks are missing at some places in the East-bound tunnel. There are some more support structures inside the tunnel. The structures need to be removed before we can place temporary tracks so that a train can use them to reach Esplanade,” said another KMRC official.
The work to remove the support structure inside the Sector V-bound tunnel is yet to begin, the official added.
Sources in the agency said “six to seven months” of the trial was needed to prepare for commercial runs.
After satisfactory results, the carrier will have to apply for an inspection by the commissioner of railway safety, whose clearance is mandatory for commercial runs.
“The entire process takes a lot of time. Hence, it is very important to be able to start trial runs by April. The physical infrastructure needs testing, especially the section under the river. The signalling system that has been installed needs to be in sync. We expect multiple problems that will need fixing. That is what trials are for,” said an official.