India’s first underwater rail tunnel, that was being constructed under the Hooghly river for establishing metro link between Howrah and Kolkata, got completed on 23 May 2017, ahead of the scheduled time.
For the construction of tunnel, a giant tunnel-boring machine (TBM) named 'Rachna' was deployed to dig the underwater tunnel that will run a length of 502 metres under the river. The machine was brought from Herrenknecht AG plant in Schwanau in Germany.
The deadline for the completion of this underwater tunnel was of July 2017.
The construction of the tunnel was jointly undertaken by Afcons Transtonnelstroy and Kolkata Metro Railway Corporation Ltd, who are tasked for implementing the East West Metro Project. Afcons Transtonnelstroy is an Indo-Russian joint venture.
Highlights of the East West Metro Project
• The entire project is 16.6 km long, out of which 10.8 km runs under the ground.
• Of this 10.8 km, 502 metres is under the water.
• The project connects Howrah to the west and Salt lake to the east.
• The stretch of 16.6 km will have 12 stations, six of which will be under the ground, while the remaining six stations will be on elevated tracks.
• The total project cost is around Rs 5000 crore.
• The final commissioning of the project is expected by December 2019, following which it will be operational.
Since the beginning, the East West Metro Project was held up several times mainly due to land allocation, slum relocation and route alignment problems among others.
The project was originally slated to be completed by 2012. Later, it was first postponed to 2015 and finally to December 2019. Digging the underwater rail tunnel was the most difficult and critical task in the entire project.
The job was completed in a time of one month and six days, about 50 days ahead of schedule.
When: 23 May 2017