India’s first underwater rail tunnel

India's First Underwater Rail Tunnel


India has completed its first underwater railway tunnel successfully. It was supposed to do so by July 2017. However, the seemingly-impossible task has been made possible by the employees of Kolkata Metro Railway Corporation Limited (KMRCL) and Afcons Transtonnelstroy. They had been building the East West Metro and have been able to complete the boring of the first-ever railway tunnel of the country. The tunnel has been created below Hooghly River and establishes a metro link between Kolkata and its neighbours Howrah. A huge tunnel-boring machine (TBM) named Rachna was used to dig the underwater tunnel. Said tunnel covers a length of 502 m under the river.

A joint venture between India and Russia

Afcons Transtonnelstroy happens to be a joint venture (JV) of India and Russia. The TBM in question was brought from a Germany plant named Herrenknecht AG, based at Schwanau. The authorities say that the work of tunnel is going ahead as was planned. The whole project is supposed to cover a distance of 16.6 km. 10.8 km of this distance would be built on the surface. 502 m passes underneath the water. The project is supposed to connect Salt Lake in the east to Howrah in the west.

Digging the tunnel

This was the hardest part of the entire project as well as the most-important one too. In all, it took a month and six days to complete the task. This meant it was completed 50 days prior to schedule. After Afcons Transtonnelstroy completes the construction part, its implementation will be taken care of by KMRCL. As per a senior official of KMRCL the work of digging was initiated on April 14, 2017. The official in question has attributed the early completion to the 250 engineers, workers, and technicians who worked round the clock in order to make sure that the work was completed before time.

Pace of work

This meant that on an average they dug 35-40 m every day. It is expected that along the entire stretch there would be 12 stations in all and six of them will be under the ground. As may be expected, the other half would be built on elevated tracks. The project is expected to be completed by December 2019. After that the east-west line would start to function. The officials at KMRCL are hopeful that judging by how they have been able to complete the digging part before time they would be able to do the same with the final deadline as well.

Some important details

The entire project has incurred a cost of around $750 million. In Indian currency it would come down to somewhere around INR 5000 crores. Ever since the project began it has got held up on a number of occasions because of issues such as allocation of slums, relocation of slums, and problems in aligning the route. The project was originally supposed to be completed by 2012. It was then pushed back to 2015 and then finally it has been decided that December 2019 would be the deadline.