About
The Chennai Suburban Railway is India's oldest continuously-operating suburban rail system — opened on 11 May 1931 as the Madras Suburban Railway. The network spans 305 km of broad-gauge electrified rail across Chennai Metropolitan Region, operated by Indian Railways' Southern Railway zone with 1.5+ million daily passenger journeys.
The network's electrification was pioneering: while the Mumbai Suburban Railway was the first to be electrified (1925, with DC), Chennai's was the first 25 kV AC suburban rail in India (1965 onwards) — establishing the AC standard that all subsequent Indian metros + suburban systems would follow. This made Chennai's electrification more economical to maintain over the long term.
The network spans three primary lines: South Line (Chennai Beach-Tambaram-Velachery, ~30 km), West Line (Chennai Central-Arakkonam, ~70 km), and North Line (Chennai Central-Gummidipoondi-Kavaraipettai, ~50 km), plus extensions. The system is interconnected with Chennai Metro at multiple stations, providing integrated transit for the metropolitan region.
Despite being India's oldest suburban network, Chennai has been progressively modernised: 12-coach AC trainsets replaced 9-coach non-AC stock progressively from 2018 onwards, with full network conversion to 12-coach trains targeted for 2026.
Cross-references
6Indian Standards, IRC codes, and InfraLens knowledge articles that bear on this project's design and execution. Each link opens the relevant reference page.
Related calculators
5InfraLens calculators most relevant for railway projects.
Notable features
- India's oldest continuously-operating suburban rail system (1931)
- First 25 kV AC suburban rail in India (1965 — established AC standard)
- 305 km network across Chennai Metropolitan Region
- 1.5+ million daily passenger journeys
- Integrated with Chennai Metro at multiple stations
- 12-coach AC trainsets progressively replacing older 9-coach stock