Delhi Metro completes tunnel at Lal Qila Metro Station

NEW DELHI: Delhi Metro on Monday announced tunnel breakthrough of the stretch between Kashmere Gate and Lal Qila. This stretch is part of the extension of the Central Secretariat corridor to Kashmere Gate via ITO.

According to a Delhi Metro official, the tunnel boring machine (TBM) emerged at Lal Qila Metro station site after making a 1,351m-long tunnel from Kashmere Gate. "The TBM was lowered at Kashmere Gate shaft on December 6, 2014, and after assembly of the machine below the ground, the initial drive began on December 26, 2014. The maximum depth of the tunnel is 16m below the earth's surface," said a Delhi Metro Rail Corporation (DMRC) spokesperson.

The tunnel passes beneath the existing Kashmere Gate elevated Metro station. The distance between the tunnel wall and the pile of the existing Metro station is 1.2m. "The tunnel also passes under the historical Dara Shikoh Library, Lothian Bridge (Delhi—Shahdara Northern Railway Line), Magazine Gate and Ambedkar University," said the DMRC spokesman.

A total of 967 rings have been inserted simultaneously along with the tunneling process. Each ring has five segments (each 275mm thick) and the length of one segment is 1.4m. These segments and rings are connected using bolts. The internal diameter of the tunnel is 5.8m. The casting of the segments was done at the Mundka casting yard.

This section is a part of the 9.37km long Central Secretariat - Kashmere Gate corridor.