How China's record-breaking maglev train silenced 'tunnel boom'

China’s CRRC has developed a novel 100-meter-long porous buffer installed at tunnel entrances to address the “tunnel boom” phenomenon caused by high-speed maglev trains exiting tunnels. This boom results from compressed air rapidly releasing as trains traveling up to 600 km/h (373 mph) emerge from tunnels, creating intense low-frequency shock waves. The buffer, made from lightweight porous materials and combined with a porous tunnel wall coating, vents compressed air gradually, reducing pressure spikes by up to 96%. This innovation promises a quieter, safer ride and fewer disturbances to nearby communities, wildlife, and infrastructure, without significantly increasing construction complexity or costs. This breakthrough is critical for the advancement of maglev technology, which can surpass conventional high-speed rail speeds limited by wheel-rail friction. China’s latest maglev prototype, capable of sustained 600 km/h service, will incorporate this buffer. The technology could revolutionize travel along major corridors like Beijing–Shanghai by offering a faster, quieter alternative to domestic flights,