First Time in Bharat: Tunnel Hoods introduced for mountain tunnels for Mumbai-Ahmedabad bullet train project
Mumbai, June 13
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
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.
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.
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.
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.
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
Reader Comments
Interesting technology. I've seen similar hoods on the Shinkansen in Japan. However, I wonder how much these add to the overall project cost. The bullet train budget is already massive - hope these don't push it further over budget.
As someone from Maharashtra who lives near the proposed alignment, this is reassuring. The tunnel boom complaint was a real concern for my village. Now at least we know they're thinking about noise mitigation. Hope the construction timelines are met too! 🙏
First in Bharat, but this technology is decades old in other countries. Good that we're catching up, but we could have started this earlier. Still, any step towards modernizing our rail infrastructure is welcome. Let's hope the project finishes on time this decade.
This is smart engineering! The piston effect in high-speed rail tunnels is well-documented. The pressure-relief vents are a clever solution. I'm curious why we need 7 mountain tunnels in Maharashtra alone - is the terrain really that challenging?
Respectfully, this kind of detail should have been shared earlier with local communities. Many people are still worried about noise and vibration from the bullet train. Better communication from NHSRCL would help build trust. Still, good to see the technical solution.
R We welcome thoughtful discussions from our readers. Please keep comments respectful and on-topic.