A section of the machine that will be used to bore a tunnel 13 metres under the Hooghly riverbed for the East-West Metro was lowered underground at Howrah Maidan on Thursday after lying idle for more than four years.
The tunnel-boring machine is scheduled to start its underground journey in April and would take four months to cover 800 metres and reach Howrah station, beyond which it will bore through the riverbed for 520 metres.
The four-year lag was caused by the state government's refusal to remove encroachments at several places.
An engineer of the Kolkata Metro Rail Corporation (KMRC), the implementing agency for the project, said it would take two months for the tunnel boring machine to cross the Hooghly and reach Calcutta.
Afcons Transtonnelstroy, the joint venture company laying tracks and building stations for the second phase of the East-West Metro between Howrah Maidan and Sealdah, has procured the machine and will operate it. The 100-metre-long machine is said to be capable of boring a 14-metre tunnel in 12 hours in "favourable conditions".
A 160-tonne gantry crane lifted the first part of this German-manufactured marvel, which costs Rs 40 crore. The crane was placed on a track over which it moved very slowly with the machine hanging from it. It was then slowly lowered underground.
The tunnel boring machine comes in eight parts and its rear section was lowered 17 metres underground on Thursday. The rest will be lowered underground over the next seven days before assembling starts.
"Boring is likely to commence in the first week of April," said Babul Supriyo, the Union minister of state for urban development.
He was at Howrah Maidan on Thursday, breaking a couple of coconuts to mark the resumption of work.
The singer-politician said he expected the first phase of the East-West Metro - between Sector V and Sealdah - to be ready by December 2017, although the deadline is June 2018.
The tunnel boring machine's immediate destination is the proposed Mahakaran station.
"We are expecting to reach Mahakaran, which is 2.7km from Howrah Maidan, by July 2017. Right now, the plan is to use this machine till Mahakaran. We may later extend it till Esplanade," said B. Deewanji, chief engineer (civil) in the KMRC.
The machine being put together came from Germany in June 2011, but lay idle all this while because land wasn't available on some stretches. About 90 families refused to shift from Bowbazar and hawkers on Brabourne Road weren't evicted either. A new alignment has since been planned, although this too isn't free of hurdles.
The KMRC has yet to get permission from the army, the custodian of the Maidan, to build the proposed Esplanade station.
Railway officials said getting clearance from the defence ministry to lay tracks for another Metro project on land owned by the army had proved difficult. The army hadn't even allowed a survey for the Joka-BBD Bag Metro, part of which will run through the Maidan, for a long time. It agreed to the survey only after Prime Minister Narendra Modi intervened.
The Archaeological Survey of India (ASI) too has objections to construction close to three heritage structures, including two synagogues. Permission from the ASI would also be required to build the proposed Mahakaran station in a new location, as proposed in the alternative alignment.
