After long delay, the tunnelling work between Jama Masjid and Delhi Gate has finally begun on the Central Secretariat — Kashmere Gate Metro corridor. A 96m-long completely assembled underground Tunnel Boring Machine (TBM) was put to work on the line on Monday. This is the longest TBM ever used in any Delhi Metro project so far and weighs approximately 500 tonnes.
It is noteworthy that for the first time in history of the Delhi Metro, a TBM has been assembled at one go. The Delhi Metro officials said that lowering the TBM at one instant not only saves time, but also saves the space in the congested area.
The TBM will emerge at the Delhi Gate. “The TBM will cover the 1,065 m stretch from Jama Masjid to Delhi Gate. The TBM lowered at the Jama Masjid is known as the rock TBM, used to tunnel the rocky surface of the stretch,” said a spokesperson of the Delhi Metro Rail Corporation (DMRC).
After facing red flags from the conservation experts — construction work on the corridor — also termed as the ‘Heritage Corridor’ — started in February, last year.
The construction work commenced with Chelmsford Club, when the National Monument Authority (NMA) gave its nod to the line.
The corridor had faced objections from the conservation experts as it passes through some of Delhi's important heritage sites including Jantar Mantar, Delhi Gate, Khooni Darwaaza, Ferozeshah Kotla, Sunehri Masjid and Red Fort, besides some lesser known but ancient shrines.
Experts had raised concerns that the vibrations caused by the Metro could cause irreparable damage to these ancient structures and may even trigger their collapse.
The 9.37 km Corridor received all the necessary clearances after DMRC hired an Australian firm to provide a cushion under the tracks, so that the vibrations produced by the moving trains do not affect the heritage structures.
Another challenge was to cause minimum noise, disturbances or traffic diversions during the construction work in the lutyens’ Zone, which the corridor touches.
The upcoming Metro station at Jama Masjid is part of the extension of the present Violet line (Badarpur to Central Secretariat) to Kashmere Gate. The Mandi House to Kashmere Gate stretch of the corridor will be operational by 2015-end. Delhi Metro’s Phase III envisages to adding another 120 km to its current network by the year 2016.