CHENNAI: In light of a minor train derailment near Tondiarpet in December last year that was caused by sand and water seeping into a tunnel, the Chennai Metro Rail Limited (CMRL) is taking steps to address similar leakage issues across the phase 1 network and its extension.

A committee formed to investigate the incident recommended that immediate action should be taken to fix the leaks and seepages in tunnels. Following this, the CMRL has floated bids for contractors to carry out the work, as reported by The Hindu. The leakage points will be plugged with polyurethane injection resin grout material, officials said.

Preventive tunnel maintenance is essential for safety, CMRL officials emphasised, adding that a leak had occurred near Sir Theagaraya College Metro a few months before the Tondiarpet incident.

Out of the 32 stations in the 45 km-phase 1 network, 19 are underground while the rest are elevated. The phase 1 extension runs for 9 km across nine stations, with only 2 stations underground.