The Mumbai-Ahmedabad High Speed Rail corridor is India's first bullet train project, built with Japanese Shinkansen technology. Covering about 508 km with a design speed of 320 km/h, it is one of the largest civil engineering projects in the country. Here is what it takes to run a train that fast safely.
Why ordinary tracks cannot handle it
At 320 km/h, a train covers nearly 90 metres every second. Small track irregularities that are harmless at 100 km/h become dangerous. High-speed lines therefore use dedicated, extremely precise tracks with gentle curves and no level crossings.
Built in the air: viaducts
Most of the corridor runs on elevated viaducts. Raising the track avoids crossings, protects it from animals and floods, and reduces land needed. Huge full-span box girders, each weighing several hundred tonnes, are cast in yards and placed using special launching machines, a method that speeds up construction enormously.
Slab track instead of ballast
Conventional railways use crushed stone ballast under sleepers, which shifts over time and needs constant maintenance. Shinkansen-style lines use slab track: precast concrete slabs fixed precisely in place, with an adjustable layer underneath. It keeps the rails accurately aligned at high speed.
Tunnelling under the sea
Near Mumbai, the line goes underground, including a section beneath the Thane creek. Boring machines and other tunnelling methods are used to build it, making it India's first undersea rail tunnel.
The aerodynamic nose
When a high-speed train enters a tunnel, it pushes air ahead like a piston, which can create a loud boom at the exit. Japanese engineers famously reshaped Shinkansen noses after studying how a kingfisher dives into water with barely a splash. The long, tapered noses of modern bullet trains reduce this tunnel boom and air resistance.
Safety systems
- Automatic train control that limits speed and applies brakes if the driver does not respond.
- Earthquake detection that detects early tremors and cuts power so trains brake before strong shaking arrives, a system proven in Japan over decades.
- Wind and rain monitoring that restricts speed in bad weather.
Frequently asked questions
Is the bullet train faster than flying?
For a route of around 500 km, door-to-door times can be competitive with flying once airport travel, security and boarding are included.
When will it open?
Construction is in progress, with sections being built in phases. Check official announcements from the National High Speed Rail Corporation for current timelines.