Slurry tunnel machines used in Bangalore Metro

The Bangalore Metro project is using slurry tunnel boring machines from Hitachi to speed up the work of creating tunnels for the Metro. This is the first time such a machine is being used in India. The 330 tonne machines need 3,000KW of power which is supplied by a diesel generator located at KSRTC’s Kempe Gowda Bus Station. They bore 18m a day, and cut round cross sections through the rock and soil to create smooth tunnels, while creating minimum disturbance to the surroundings. The machines are an alternative to the normal drilling and blasting used to create tunnels. The tunnelling process with the machines creates slurry which is carried away by pipes to a slurry treatment plant, where the water is separated to produce slurry again, and the solid material is sent to filling yards. The machines are taken apart and reassembled at every underground station site of the Metro – Central College, Vidhana Soudha, Cricket Stadium and City Railway Station. The entire operation is controlled and monitored from a central plant at . With the current pace of work, the machines are expected to create two tunnels of around 4.5km by August 2012.