Chennai's Double-Decker Metro Update: A Step Closer To Completion

Chennai's ambitious double-decker Metro construction, part of Corridor 4, is making significant progress.

This double-decker construction will be the first in India to have both Metro lines supported on the same pier. The stretch will feature four stations-Alwarthirunagar, Valasaravakkam, Karambakkam, and Alapakkam-developed at two levels. These stations will have a common concourse level with 'island platforms' operating for 5 km.

Around 99 per cent of the piling work and 78 per cent of the pile cap work has been completed. The elevated corridor viaduct spans 3.75 km and includes a double-decker structure, according to a report in DTNext. CMRL officials have highlighted that this construction has been particularly challenging due to design complexities, space constraints, and the diversion of various utilities.

Corridor 5 merges at pier 110 of Corridor 4, where the double-decker structure begins, and de-merges at pier 242. "With 192 piers between 110 and 242, the construction is going on at a fast pace," stated a CMRL official. Due to space constraints, cranes could not be used for erecting the U-girders from piers. Instead, a launching girder (LG) was employed, successfully erecting U-girders in 13 spans with approximately 52 U-girders.

Despite several initial delays, the double-decker Metro construction works moved at a rapid speed. From land acquisition to heavy utility diversions, the Chennai Metro Rail Limited (CMRL), along with the contractor, had to spend many months on preparatory works. An offical told the publication: "Till today, we've successfully erected 27 spans on both levels of the double-decker corridor 4 and 5 pier caps, and are now ready for U-girders installation. Additionally, the corridor 5 level pier works are also progressing well."

The official claimed that the service line that facilitates the movement of rolling stock, work is ongoing from Corridor 4 to Corridor 5. "Till now, 26 out of 35 piers have been completed up to corridor 4 level in service connection, and 15 level pier arms have been erected," added the official.

In Alapakkam station, substantial progress has been made with 11 piers now standing tall, marking the successful installation of the upper platform pier arms. In Karambakkam station, all the concourse level piers casting have been completed and level pier arms installation is in progress. Pier works are also advancing at Valasaravakkam and Alwarthirunagar stations.

The rapid progress of the double-decker Metro construction in Chennai marks a significant step forward in the city's urban infrastructure development, promising enhanced connectivity and commuter convenience upon completion.