Chennai Metro Rail Ltd. is mulling laying ballast tracks in one of the depots as part of its phase II project.
There will be two depots in the phase II project for maintenance of trains, one in Poonamallee and another at Madhavaram.
The CMRL has been considering laying a ballast track — the traditional track as can be seen in Indian railways with crushed stones laid between rails — in the Poonamallee depot to save on capital expenditure.
According to officials of the CMRL, no decision has been taken on whether Madhavaram depot will have ballast or ballastless tracks. “This depot, built at a cost of ₹225 crore, will have 24 tracks and we think we can save substantially on the initial investment with ballast tracks,” an official said.
The soil has to be treated if a ballastless track is to be laid at Poonamallee depot and this may cost ₹80 crore to ₹90 crore.
But sources say this may not be a good idea as ballast tracks will push up the cost of maintenance. “Ballastless is the way forward and hence was laid at Koyambedu years ago for the phase I project and has been in operation with barely any issue at all in the last several years now. Why at all switch to a ballast track now for a depot alone? What they want to save in the initial capital cost will be spent on maintenance over the years. Also, the maintenance of the ballast track is much more difficult as well,” a source said.
Another source said ballastless tracks serve a longer period without causing much issue when compared to ballast tracks.
“The phase II is estimated to cost ₹61,843 crore. When we are spending so much for the whole project and laying a ballastless track across the 118.9 km network itself, I wonder if we have to really save on this issue. Even in Koyambedu, the soil had to be treated although it did cost less when compared to the Poonamallee depot,” he added.