Summary:
Tunnelling engineers said the smooth progress was owing to the excellent nature of earth 13 meter under the Hooghly riverbed. KOLKATA: Prerna, the tunnel-boring machine (TBM) drilling the Kolkata-bound tunnel from Howrah, is moving at express speed. "Unlike tunneling on land when over-ground activities and structures pose a major challenge, it is smooth sailing under the river. It meant there would be no delays henceforth," said Biswanath Deewanji, chief engineer of Kolkata Metro Rail Corporation (KMRC). At this rapid pace, it is expected to touch the 100-metre mark by end of Thursday..