CHENNAI (Metro Rail & Steel): As Chennai’s eagerly anticipated Phase 2 of the metro rail system gears up for its unveiling, preparations are underway to introduce an innovative infrastructure approach. The upcoming phase will witness the deployment of 63 steel bridges strategically positioned across various locations, enabling the smooth passage of driverless trains over buildings, flyovers, and constrained areas.
These steel bridges are a crucial addition where conventional concrete viaducts with pillars cannot be constructed due to restricted vertical clearance or the presence of underlying structures and roads. A recent milestone in this endeavor was marked by the installation of a hefty 40-meter-long steel girder bridge, weighing a substantial 222 Tonnes. This installation took place above Chennai bypass flyovers on Mount-Poonamallee High Road, near Porur, as part of the Phase 2 construction spanning from Porur to Poonamallee Bypass.
Scheduled to be accessible to the public in stages between 2025 and 2028, the 116.1-kilometer Phase 2 expansion is a significant step in Chennai’s metro rail network development. An official from the metro rail confirmed that these 63 steel girders will find their place in crucial locations such as Chennai Bypass, Thelliyaragaram, Poonamallee junction, Porur Junction, Valasaravakkam, Adambakkam, Ramapuram junction, Kathipara, Kalliamman Koil Street, Butt Road, Echankadu, Perumbakkam, Medavakkam, Retteri, MMBT, ICF crossing, and the national highway crossing in Koyambedu.
CMRL spokesperson L Girirajan emphasized that these steel girders are designed to match the span and load capacity of their concrete counterparts, ensuring safety while presenting advantages in scenarios where limited vertical clearance is a constraint. He further highlighted the cost-effectiveness and aesthetic benefits associated with using steel girders, which reduce the need for excessive pillars and complex environmental impact studies.
While acknowledging the faster installation process of steel girders, officials stressed the importance of executing this work during night hours to minimize traffic disruptions. The intricate process demands heavy lifting equipment, including 500-metric-tonne cranes, and continuous monitoring throughout the construction phase.