TBMs for underground section of Metro’s Purple Line launched

Kolkata: The lowering or launching of the tunnel boring machines (TBMs) that will construct the Purple Line's underground section began on Thursday. Despiteuncertainty over the Kidderpore Metro station, Metro Railway, which operates the city's rapid transit network, and RVNL, which is implementing the 14 km Purple Line or the Joka-Esplanade corridor (now extended to Eden Gardens), are proceeding with the construction of the underground tunnels.

As reported by TOI on Mar 9, the TBMs, each 90 m long and weighing 650 tonnes, were almost entirely made in Herrenknecht's Alinjivakkam unit in Tamil Nadu. They were dismantled into 18 parts each to be transported in trailers across 1,653 km from TN to Kolkata. During this time, they were stored in trailers outside St Thomas' Boys School. A 17 m deep shaft has been constructed inside the school premises to launch the giant machines. The machines will be assembled underground in the next 45 days, and the first drive may start byJune end.

"Contractors L&T are deploying the TBMs to construct the 2.65 km twin tunnels from Kidderpore to Park Street," a Metro official said. The TBMs will first build 1.7 km from St Thomas' to Victoria. The second drive will span 950 m from Victoria to Park Street. The line's northern end, from Park Street to Esplanade, will be built using the cut-and-cover method. The Purple line is supposed to have four stations: Kidderpore, Victoria Memorial, Park Street, and Esplanade.

"But Metro Railway is not sure if the Kidderpore station will be built at all, as land at Kolkata Police's Bodyguard Lines at Ekbalpore is not available yet, despite repeated pleas to the state govt," a Railways official said. Meanwhile, contractors L&T, awarded the Rs 2,447 crore underground package which spans 5 km, started construction of the Victoria station in Sept 2023 and began casting tunnel ring segments in their Sarkarpool (near Mahestala) unit in July 2024.

"We seem to have waited for eternity to avail the Purple Line, which is being extended on both sides—beyond Joka and towards BBD Bag. Hopefully, the land impasse over Kidderpore Metro station will end soon, and people along Diamond Harbour Road will be spared the ordeal of travelling in crowded buses," Ekbalbore Road resident Farooq Ahmed said.

Kolkata: The lowering or launching of the tunnel boring machines (TBMs) that will construct the Purple Line's underground section began on Thursday. Despiteuncertainty over the Kidderpore Metro station, Metro Railway, which operates the city's rapid transit network, and RVNL, which is implementing the 14 km Purple Line or the Joka-Esplanade corridor (now extended to Eden Gardens), are proceeding with the construction of the underground tunnels.

As reported by TOI on Mar 9, the TBMs, each 90 m long and weighing 650 tonnes, were almost entirely made in Herrenknecht's Alinjivakkam unit in Tamil Nadu. They were dismantled into 18 parts each to be transported in trailers across 1,653 km from TN to Kolkata. During this time, they were stored in trailers outside St Thomas' Boys School. A 17 m deep shaft has been constructed inside the school premises to launch the giant machines. The machines will be assembled underground in the next 45 days, and the first drive may start byJune end.

"Contractors L&T are deploying the TBMs to construct the 2.65 km twin tunnels from Kidderpore to Park Street," a Metro official said. The TBMs will first build 1.7 km from St Thomas' to Victoria. The second drive will span 950 m from Victoria to Park Street. The line's northern end, from Park Street to Esplanade, will be built using the cut-and-cover method. The Purple line is supposed to have four stations: Kidderpore, Victoria Memorial, Park Street, and Esplanade.

"But Metro Railway is not sure if the Kidderpore station will be built at all, as land at Kolkata Police's Bodyguard Lines at Ekbalpore is not available yet, despite repeated pleas to the state govt," a Railways official said. Meanwhile, contractors L&T, awarded the Rs 2,447 crore underground package which spans 5 km, started construction of the Victoria station in Sept 2023 and began casting tunnel ring segments in their Sarkarpool (near Mahestala) unit in July 2024.

"We seem to have waited for eternity to avail the Purple Line, which is being extended on both sides—beyond Joka and towards BBD Bag. Hopefully, the land impasse over Kidderpore Metro station will end soon, and people along Diamond Harbour Road will be spared the ordeal of travelling in crowded buses," Ekbalbore Road resident Farooq Ahmed said.