Mumbai-Ahmedabad Bullet Train: First-ever tunnel hoods in India

For the first time in India, tunnel hoods are being installed on the Mumbai-Ahmedabad Bullet Train corridor. This technology will manage pressure waves, reduce the 'tunnel boom' effect, and ensure a quieter, smoother journey at high speeds.

Tunnel Hoods are being installed at mountain tunnel portals on the Mumbai-Ahmedabad Bullet Train Project. This is the first time such tunnel hood technology has been designed and implemented for railway tunnels in Bharat, according to the National High Speed Rail Corporation Limited (NHSRCL)

The Mumbai-Ahmedabad Bullet Train corridor traverses challenging terrain and includes seven mountain tunnels in Maharashtra and one mountain tunnel in Gujarat. Tunnel hoods are being provided at both ends of these mountain tunnels.

The Science of Tunnel Boom

Explaining the need for the system, the release stated that when a high-speed train enters a tunnel, it pushes a large volume of air ahead of it, similar to a piston moving inside a cylinder. This sudden compression of air generates pressure waves that travel through the tunnel. If not properly managed, these pressure waves can create booming noise when a train passes through the tunnel.

How Tunnel Hoods Provide a Solution

Tunnel hoods act as a transition zone between the open environment and the confined tunnel space. By allowing air to enter and exit more gradually, they help control pressure changes and improve the overall aerodynamic performance of the system.

The tunnel hoods on the Bullet Train corridor are designed to minimise tunnel boom and noise generated by high-speed train movement while exiting, and lower disturbance to surrounding communities. It is also designed to support the safe and efficient operation of trains travelling at very high speeds.

In simple terms, the tunnel hood helps the train and the air adjust to each other gradually rather than abruptly, making high-speed rail travel quieter, smoother and more comfortable.

Advanced Design with Pressure-Relief Vents

One of the distinctive features of these tunnel hoods is carefully designed pressure-relief vents or windows. These windows or openings allow a portion of the compressed air to escape gradually into the atmosphere as a train enters the tunnel. This reduces the intensity of pressure waves, minimises tunnel boom and helps maintain smoother airflow.

Adopting International Best Practices

The release further added that Tunnel hoods are a common feature on high-speed rail systems in countries operating bullet trains, where trains travel at speeds exceeding 300 kmph. Their adoption on the Mumbai-Ahmedabad Bullet Train Project reflects the use of advanced engineering solutions and international best practices to ensure world-class standards of safety, comfort and environmental performance. (ANI)

(Except for the headline, this story has not been edited by Asianet Newsable English staff and is published from a syndicated feed.)