CHENNAI: A 3.75km double-decker elevated metrorail line between Alwarthirunagar and Alapakkam that is being built at 24m height – the same as an eight-story building – using specially designed imported girders and gantries will give Madhavaram residents easy access to core city areas in two years.
The double-decker line with four stations will be an interchange, linking corridor-4 and 5 in phase-2.
As the line is being constructed on a narrow road where cranes cannot be used, engineers are using launching girders and feeding gantries,, which will sit on top of the pillars, to install viaducts or ‘U’ shaped precast girders by hoisting them.
This equipment builds elevated corridors without causing any disturbance to the moving vehicular traffic below. Metrorail officials said the double-decker line is part of the Powerhouse to Porur line on corridor-3, which is likely to be ready by mid-2026.
“The launching girder and the gantry cost around 15crore. They were specially fabricated in China for constructing elevated lines on roads where cranes cannot be operated. We are using these girders and gantries on the challenging double-decker stretch where both the line and the stations are being built on a single row of pillars. All four stations will have a common concourse (ticketing level) with two different platforms,” T Archunan, director (projects) had said.
Construction of the two-deck elevated line is a slow and challenging process as several prestressed concrete segments are assembled after curing concrete pillars to build the concourse and two track levels. The double-decker line will have four stations – Alwarthirunagar, Valasaravakkam, Karambakkam and Alapakkam.
When the line opens, commuters can travel from Madhavaram and southern suburban areas such as Alandur, Madipakkam and Medavakkam to the shopping hub in T Nagar, Marina Beach and IT corridor on OMR by switching platforms in any of the double-decker stations.
“There are not many MTC buses for us to get to the city. Travelling in a cab or auto costs a lot as we have to travel at least 15 to 20km to get to places such as T Nagar. We can travel in metro trains in comfort, at a comparatively lower cost and in less time,” said H Chandran, a resident of Madhavaram.
