Chennai Metro Rail to start repair work to fix leakages in tunnels

Chennai Metro Rail to address tunnel leakages in phase I and extension projects through preventive maintenance measures.

Chennai Metro Rail plans to carry out work to prevent leakages in the tunnels of its phase I and phase I extension projects.

Last December, sand and water flowed through a hole in the tunnel and resulted in a minor derailment of a train near Tondiarpet in the phase I extension project. Subsequently, a committee was formed to investigate the issue and the report recommended that the leakages and seepages in tunnels should be arrested at the earliest. The Commissioner of Rail Safety too was informed of the incident, and a report was sent.

According to officials of Chennai Metro Rail Limited (CMRL), preventive maintenance of tunnels across the network is crucial for safety. In the 45 km network of phase I project, about 55% of the network has been built underground and in the 9 km section of the phase I extension network, a small section between Washermanpet and Tondiarpet alone is underground. 

The tunnel section in the phase I extension has assumed more significance now because of the incident, sources said. “A few months before the incident at Tondiarpet, a similar episode occurred near Sir Theagaraya College Metro as well. Hence, the committee and the report recommended that across the whole network, steps should be taken to arrest leakages in the tunnel. If stopped and plugged right at the beginning of a seepage, then major incidents could be avoided,” an official said. 

CMRL has floated bids now looking for a firm to carry out the work. The contract is likely to be awarded by the end of May. “There are many locations where there is minor seepage of water in both phase I and phase I extension network. The contractor will use polyurethane injection resin grout material to seal the leakages. There should be periodic inspection in the tunnels and station structures to check and measure the leakages and stop them,” another official said. The work will be carried out at midnight and early morning when there are no train services.