India is all set to open its first underwater metro line in Kolkata which will pass through a tunnel that is almost 100 feet under Hooghly. The first of its kind underwater tunnel is almost complete while the second one will soon be ready.
Kolkata, known as the ‘City of Joy’, is set to open the underwater tunnel next week. This tunnel is a crucial link for the railways’ 16.6km East-West Metro project in Kolkata.
The twin tunnels, one east-bound and the other west-bound, are built 30 meters below the riverbed. Travelers between Howrah and Mahakaran stations will be under the riverbed for only about a minute when the train will pass through the tunnel at 80 km per hour. Of the 16.6km route of the new East-West Metro project, the tunnel covers 10.6km, of which 520 meters is under the river.
The tunneling work, which started in April 2016, is being built at an expense of Rs 60 crore. The total cost of the project is estimated to be around Rs 9000 crore.
The East-West Metro is scheduled to be operational by August 2019.
The internal diameter of the tunnel is 5.55 meter and the distance between both the tunnels is 16.1 meter.
The train is designed to run without a driver and will have a capacity of 1000 passengers. There will be six air-conditioned coaches in total which will be running between Howrah and Sealdah – each of which has a footfall of about 10-12 lakh passengers. There will be walkways in the tunnels to evacuate passengers in case of emergency.
Over 10 lakh ton of mud has been dug out for the construction of this tunnel. The tunnel-boring machines are being used for the first time in Eastern India. The Kolkata underwater metro tunnel is unique to India because never before has a tunnel been made under a flowing river in the country. In India, there isn’t even any experience of building roads under the river, thus making the Kolkata tunnel a complete technological marvel which will see trains chugging through it every two and a half minutes.
One year of homework was done before the execution of the plan as the tunneling process cannot go on for a long time. The use of a standard gauge is unique in India, it is the latest technology that has been utilized to make sure that the tracks have sharp curves, so as to avoid the tunnel passing under a lot of heritage buildings.
For tunneling below the river, waterproofing, the water tightness and the design of the gaskets were major challenges, because the tunnel is being constructed to be in service for 120 years, no leakage could be afforded.
The Bullet Train Project
Besides the tunnel under the Hooghly river, the railways are conducting drilling work for a seven-kilometer-long under-sea route of the Mumbai-Ahmedabad rail corridor to identify the soil condition for India’s first bullet train path.
Passengers will enjoy the thrilling experience of traveling at a maximum speed of 350 km/hour under the sea, another first in the country, near Thane in the upcoming bullet train project connecting the two metropolises.