LMRC completes 40% tunnel work in phase 1
Up line tunnel and down line tunnel from Bapu Bhawan to Hazratganj is expected to be completed by July this year.lucknow Updated: Apr 06, 2017 15:41 IST
The Lucknow Metro Rail Corporation (LMRC) has completed 40% of the tunnel work in the first phase from Bapu Bhavan to Hazratganj in just over three months.
The length of the up line tunnel is 811.5 metres while the down line tunnel is 782 metres long, said Daljeet Singh, director works and infrastructure (LMRC) while talking to Hindustan Times.
Around 120 people are working 60 feet below the earth to construct the 3.7-km-long tunnel connecting Charbagh and Hazratganj.
The Rs 1,190-crore underground project is not only about money and advanced technology used by the LMRC, but it’s also about passion and dedication to complete the work.
“Currently, two TBMs are working in the tunnels -- upline and downline. The first TBM named ‘Gomti’ has reached 300 metres while the second ‘Ganga’ has reached 75 metres,” he said.
The tunnel has a number of cables and wires, laid around in 5800-mm wide internal diameter of the tunnel. However, the outer diameter of the tunnel is 6350 mm. The working passage is hardly a feet wide, as major chunk of space is occupied by tunnel boring machine ‘Gomti’ and ‘Ganga’ which are digging earth without any break.
The oxygen supply in the tunnels is as good as on the ground. Proper ventilation is ensured through flexible duct of 1.4 m diametre. Minimum 0.5m/s air flow is maintained to ensure proper ventilation. Monitoring of gases like oxygen, methane, carbon monoxide and hydrogen sulphide is done at every 4 hours and there’s water-proof lighting at every 6m in the tunnel. Emergency lights are fixed at every 36m.
Communications within the tunnels are through inter-com phones fixed at every 100m.
- There is a fire alarm box at every 250 metres and fire hose at every 50 m in the tunnel.
- Provision of emergency escape breathing devices (22 in each TBM).
- Provision of first aid boxes at shaft bottom in TBMs, locos, tunnel control room, rescue basket and ambulance.
Both tunnels are moving eight meters ahead every day and earth is being dug from 60 feet below. At this rate, the first tunnel would be completed by the end of June while the second would be completed by end of July. After that, next tunnel would start, said Daljeet Singh.
In all, 579 rings would be required for the upline tunnel while 559 rings would be required for the downline tunnel. Till now, 221 rings have been placed in the upline tunnel while 59 rings have been placed in the downline tunnel, he added.
The tunnel is being built by LMRC engineers without any disturbance to surface traffic running on Vidhan Sabha Marg.
However, the tunnel work from Charbagh to KD Singh ‘Babu’ Stadium would be completed station wise. A part of the tunnel will pass below the Haider Canal when the TBM will dig the road from Charbagh to Hussainganj in the last phase of construction. On this stretch tunnelling would be done 19 metres below the surface.