Chennai, Oct 2:
Chennai’s upcoming Vadapalani–Poonamallee Metro stretch is set to add a distinctive engineering feature to the city’s expanding Metro network, with two Metro corridors sharing a common elevated structure along a crucial section.
The 14.64-km stretch, part of Corridor 4 of Phase II, will connect Poonamallee Bypass with Vadapalani. The line will provide a new rapid-transit link for residents of Poonamallee, Porur, Valasaravakkam and surrounding western suburbs.
The most striking feature is the nearly 4-km double-decker section between Porur and the Kodambakkam side. Corridor 4 and Corridor 5 have been designed at two different levels on a common structure, allowing two Metro lines to use the same alignment while reducing the requirement for additional road space.
Four stations — Alwarthirunagar, Valasaravakkam, Karambakkam and Alapakkam — form part of this double-decker arrangement. The two corridors will have platforms at different heights, making these stations among the more unusual structures in Chennai’s Metro network.
The elevated structure has also been designed around single-pillar support in this stretch. The engineering solution was adopted to overcome space constraints along some of the city’s busiest roads while keeping traffic movement largely uninterrupted during construction.
The Vadapalani end presents another engineering challenge. The new Corridor 4 viaduct crosses over the existing Phase I Metro line and the busy Jawaharlal Nehru Salai. Special construction methods were adopted to install the viaduct components without disrupting the existing Metro service and road traffic.
The stretch will also bring Phase II closer to Chennai’s existing Metro network. Vadapalani is already an important station on the current corridor, and the new line will enable passengers from the western suburbs to connect with the established Metro system.
The trains and signalling infrastructure have been designed to support automated, driverless operation. The initial service, however, will depend on the final commissioning and operational clearances.
With its double-decker alignment, two-level stations and integration with the existing network at Vadapalani, the Poonamallee–Vadapalani stretch is likely to become one of the most distinctive sections of Chennai Metro when Phase II services begin.