CHENNAI (Metro Rail News): Light House station is the first shallow underground station which is being built by Chennai Metro Rail Limited (CMRL). This station is designed with a platform on the first level and a mini-concourse on the second. It is going to be the longest station of phase 2 which is built over 300 m. Passengers will go to level 2 to get a ticket and then come up to level one to board the train.
This is an important terminal station for the stretch between Light House and Poonamallee, and after its completion, people from across the city will have easy and quick access to Marina beach. CMRL has already obtained the Coastal Regulatory Zone (CRZ) clearance necessary for the construction of this station.
CMRL has informed that they have planned it as a shallow underground station to secure the marine ecosystem. “In this location, unlike in other stations, where we go as deep as 20 m, the maximum depth will be 15 m. Also, the concourse is coming up on the second level and the platform on the first level, whose depth will be about 12 m. This is because we did not want to use the tunnel boring machines below the 12-m mark,” an official said, Hindu reported.
While one entry and exit will be near Queen Mary’s College, another will be constructed near Light House, and the space will be small, just about 70-80 m long, resembling a subway. The entry and exit structures of the station will be designed aesthetically to give a view of the beach as well.
“While the platform itself will be 140 m, the whole station length totals to around 300 m because it has to accommodate facilities like stabling and crossover,” another official said. Also, to operate the system even in case of heavy rains or flooding, the entry/exit structures will have flood gates, and the tracks will have sumps to pump out any water seepage.
Officials said they would take various steps during construction as it would be pretty tough to build an underground station due to the sandy soil.
“We have to take measures so that the soil does not collapse. For that, we have to create a trench, increase the density of bentonite (a substance used in construction as a binding material) and use bentonite slurry, do concreting, lower the reinforcement cage and then build a diaphragm wall (a station box),” the official added.
