Mumbai-Ahmedabad bullet train: How canted turnouts help trains switch tracks at 320 kmph

Advanced railway technology is being introduced in India through the country’s first bullet train corridor, including a specialised track mechanism known as a canted turnout.

Designed to maintain stability during track changes, the technology allows high-speed trains to switch between tracks smoothly at speeds of up to 320 km/h.

The technology is being deployed by the National High-Speed Rail Corporation Limited (NHSRCL) on the 508-km Mumbai-Ahmedabad High-Speed Rail corridor, Moneycontrol reported. It aims to improve passenger comfort and safety while maintaining track stability at high speeds.

On conventional railway networks, trains generally need to slow down significantly when switching tracks. This is because a turnout, the point where one track branches into another, does not always provide the same banking, or cant, found on a standard curved section of track, the report said.

When a train passes through a flat turnout at high speed, passengers can experience sudden lateral forces. These forces can cause vibrations and discomfort while also increasing stress on the train and track. Conventional turnout designs, therefore, present challenges for high-speed rail operations.

How a canted turnout works

A canted turnout addresses this challenge by maintaining the track’s banking, or cant, through the turnout where the tracks diverge.

On a conventional curve, the outer rail is raised relative to the inner rail. This elevation helps counteract the outward forces generated when a train travels around a curve at speed. A canted turnout maintains this elevation profile through the switching section.

This allows a high-speed train to switch from one track to another while gradually managing lateral forces, improving stability and passenger comfort during the transition.

Understanding point machines and turnout systems

A turnout is the section of track that allows a train to move from one line to another. It uses movable rail components to direct the train onto the selected route.

These movable components are operated and secured by point machines. The machines move the rails into the required position and lock them before a train passes through the turnout.

On high-speed rail corridors, turnout and point-machine systems have to meet stringent engineering and safety requirements because even small deviations can have a greater impact at high speeds.

Why canted turnouts matter for high-speed rail

The Mumbai-Ahmedabad High-Speed Rail corridor is designed for train speeds of up to 320 km/h. At such speeds, track geometry and alignment become particularly important because small irregularities can generate significant dynamic forces.

According to NHSRCL, canted turnouts help reduce vibrations and manage lateral forces as trains move through track transitions. The system can also reduce stress on the train and track, potentially helping lower maintenance requirements over time.

The use of canted turnouts is therefore an important part of the engineering design of India’s first high-speed rail corridor, where maintaining stability and passenger comfort during track transitions is critical.