By IANS
New Delhi : As many as 14 tunnel boring machines (TBMs) will be deployed simultaneously for laying out the Delhi Metro network in time for the 2010 Commonwealth Games. Delhi Metro Rail Corporation (DMRC) said no country in Asia has so far put to work so many TBMs at the same time.
“For the first time in any Asian city, 14 TBMs will be used simultaneously for making metro tunnels,” DMRC chief spokesman Anuj Dayal told IANS Tuesday.
“Of the 120 kilometres of phase two metro construction, we are building 30 kilometres underground and TBMs will be used for 16 km. The rest of the underground work will be done with the cut-and-cover method,” Dayal said.
“Weighing over 65 tonnes each, these machines have been imported from Germany and Japan. Two machines are already operational in Malaviya Nagar and two more have been lowered near the INA market,” Dayal added.
The remaining 10 units, including four to be used especially for the airport line, will be put to use soon. They will also be used near the AIIMS, Green Park and Hauz Khas.
Over 300 experts, mainly from Singapore, the US, Britain and China, are supervising the deployment of these machines.
He said all buildings below which the TBM are being deployed will be safe and will also be monitored during the construction by using several techniques like crack meters and settlement meters. These special boring machines are also known as Earth Pressure Balancing Machine.
“This tunnelling technique is the safest method internationally and has also been used in construction of the (English) Channel tunnel connecting Britain and France below the sea bed,” the spokesman said.
All TBMs will finish work by December 2009 after which electrical, signalling and other works will be taken up. The airport tunnelling will take some more time.
The Delhi Metro, the capital’s modern and sleek mass transport system, ferries over 600,000 passengers every day over its 65-km network.