Bullet train corridor to debut movable crossings for high-speed track changes
The Mumbai-Ahmedabad high-speed rail project will use movable crossings and dual point machines to enable safe track changes at speeds up to 320 kmph.
As the Ministry of Railways works towards starting operations on the priority section of the Mumbai-Ahmedabad bullet train corridor next year, the project is rolling out technologies meant to keep trains stable and safe at speeds of up to 320 kmph. Among them is a specialised track-switching system that allows a train to move from one track to another without compromising the precision that high-speed running demands.
On conventional Indian Railways lines, trains change tracks through a turnout, where a small gap exists at the point the two tracks meet. At high speed, passing over that gap generates greater impact, vibration and wear. The National High-Speed Rail Corporation Limited (NHSRCL) has said the Mumbai-Ahmedabad High-Speed Rail (MAHSR) project will instead use turnouts fitted with movable crossings, also called swing-nose crossings.
In this arrangement, the movable part of the crossing shifts into position together with the switch rails, creating a continuous running surface for the wheels. NHSRCL described the technology as a fundamental requirement for safe, reliable operation at design speeds of up to 320 kmph and a decisive departure from the fixed-crossing turnouts used on conventional lines. The aim is a smoother, more comfortable ride for passengers, along with less wear on track and train components.
Each high-speed turnout on the corridor will carry two point machines. One drives and locks the switch rails, while the second operates and locks the movable crossing. Both must reach their correct positions before a train is permitted through. The signalling system verifies the position and locking of each component, and only after these checks are complete is the route cleared.
Multiple layers of detection continuously monitor the switch rails, the movable crossing and their locking. If the required position and locking are not confirmed, the signalling system will not authorise movement through the turnout — a safeguard the corporation considers especially important for a railway designed for 320 kmph operations.
Compared with a fixed crossing, where the wheel must bridge a gap at the crossing nose, the movable crossing offers a gap-free surface with continuous wheel guidance. That reduces dynamic impact, lowers vibration and structure-borne noise, and cuts wear on wheel flanges and crossing components. NHSRCL also points to higher intrinsic operational safety and longer maintenance intervals.
The turnouts are being built to meet demanding requirements: higher actuation forces with precise stroke control, positioning tolerances measured in millimetres, robust locking to resist high lateral forces at 320 kmph, proven performance under Indian climatic, vibration and electromagnetic conditions, and integration with high-integrity detection systems that meet high-speed signalling safety integrity levels.
Much of this will be invisible to passengers. But the movable crossing, the twin point machines and the layered safety checks together determine how the bullet train will change tracks once commercial services begin.