India's Bullet Train to Use Canted Turnouts for Smooth Track Changes at 320 kmph

India's first bullet train corridor is introducing a set of engineering systems that are new to the country's rail network, with track-switching technology among the most critical. The Mumbai-Ahmedabad high-speed rail line, being built by the National High-Speed Rail Corporation Ltd (NHSRCL), is designed for speeds of up to 320 kmph, which turns a routine manoeuvre such as changing tracks into a complex technical challenge.

On conventional railways, the point where one track branches into another is typically laid without the banking used on curved sections. When a train passes through such a turnout, the wheels meet a sudden change in track geometry, producing higher forces, vibration and passenger discomfort. Conventional services therefore slow down considerably at certain track changes.

For the high-speed corridor, NHSRCL is using canted turnouts, which preserve the cant, or banking, of the track through the switching section. On a normal curve, the outer rail is raised relative to the inner rail to counter the forces generated as a train rounds the bend. A canted turnout is designed so that a train can move between tracks while retaining appropriate cant, reducing abrupt changes in the forces acting on the train and its wheels. For passengers, the result is a smoother track change at high speed.

A turnout is the section of track that lets a train move from one line to another, with movable components directing it towards the chosen route. Point machines move and lock those components into position. Together they form part of the signalling and track system that allows trains to change tracks safely. On a high-speed railway, these components must meet far tighter engineering requirements than on conventional services.

Beyond passenger comfort, the technology can reduce wear on wheels and rails, potentially lowering maintenance needs over the life of the railway. It is one of several specialised systems being introduced under the project.

The 508-km corridor will connect Mumbai and Ahmedabad through Maharashtra and Gujarat. It includes eight mountain tunnels — seven in Maharashtra and one in Gujarat — along with bridges, viaducts and stations. Sixteen ventilated hoods are being built at the entrances and exits of the tunnels to manage the pressure and sound generated when a high-speed train enters or exits, regulating the booming noise produced by operations. A train moving at very high speed pushes a large volume of air ahead of it into a confined tunnel, an effect similar to a piston in a cylinder. Conventional Indian tunnels generally do not require such systems because trains run at much lower speeds.

The train is currently undergoing a squeeze test to assess the strength of its body structure. Components including the car body, bogies, propulsion system, vehicle electronics, wheels and pantograph are being tested.

The first section of the corridor is expected to be completed by December 2026. The first operational section is planned between Surat and Vapi, covering around 100 km, with services targeted for August 15, 2027; the train is expected to cover that distance in about 20 minutes. The full corridor, from Bandra-Kurla Complex in Mumbai to Sabarmati in Ahmedabad, is expected to be completed by December 2029. The project was formally launched on September 14, 2017, when Prime Minister Narendra Modi and then Japanese Prime Minister Shinzo Abe jointly laid its foundation stone.