Kolkata scripted history when a metro rail rake successfully completed the trial run on India’s first underwater rail tunnel at 11.45 am on Wednesday (12 April).
The metro rail rake, powered by a battery-operated locomotive, travelled at a moderate speed from Esplanade to Howrah Maidan through the 520-metre tunnel under the Hooghly river that flows by Kolkata.
This comes nearly 40 years after India’s first metro rail services started in Kolkata. Metro rail officers said that trial runs will be conducted over the next five to seven months and after a complete safety audit, commercial operations between Esplanade and Howrah Maidan will start by the end of this year.
Kolkata will then join the likes of London, Paris, New York, Cairo and Shanghai which boast of underwater train services under the Thames, Seine, Hudson, Nile and Huangpu respectively.
After crossing the underwater tunnel below the Hooghly, the rake stopped at the Howrah station, the country’s deepest metro rail station 33 metres below ground level. A team of top metro rail officers conducted a small ceremony there before boarding the rake on its onward journey to Howrah Maidan.
The twin tunnels below the Hooghly run 26 metres below the ground level. The depth of the river is 13 metres and the tunnels run another 13 metres below the bed of the river.
The tunnelling work under the river was completed between April and July 2017. The tunnels have hydrophilic gaskets installed between concrete layers to prevent any water seepage.
Once commercial operations start, trains will travel at a speed of 80 kilometres per hour through the tunnels to cross the river in 45 seconds.
The 2.5 kilometre section between Esplanade and Howrah Maidan is part of the 16.7 kilometre long East-West Metro, or the ‘Green Line’, between Salt Lake Sector V and Howrah Maidan.
A 9.4 kilometre stretch from Salt Lake Sector V and Sealdah is already operational. But the 2.5 kilometre section between Sealdah and Esplanade has faced repeated roadblocks due to three major cave-ins.
While that has delayed the construction work on the Sealdah-Esplanade section, the metro rail authorities decided to operationalise the Esplanade-Howrah Maidan section.
The trial runs in the Esplanade-Howrah Maidan section were to have started on Sunday (9 April), but were delayed due to some last-minute technical issues.