For decades, high-speed rail engineers have been wrestling with an invisible troublemaker—compressed air. When a train explodes out of a tunnel at blistering speed, it unleashes a low-frequency “tunnel boom” that can rattle windows, startle wildlife, and irritate entire neighborhoods. The faster the train, the louder the boom. At the extreme speeds planned for next-generation magnetic levitation trains, the problem threatened to derail progress.
Now, China’s railway engineers claim they’ve cracked the code. Their solution? A 328-foot (100-meter) sound-absorbing buffer at the tunnel mouth, acting like a silencer for the world’s fastest trains. Made from lightweight, porous material with a matching porous coating along the tunnel’s interior, this barrier lets compressed air bleed off gradually rather than explode outward in a sonic punch. Early tests show it slashes pressure fluctuations by up to 96%—nearly eliminating the boom altogether.
Continue reading… “China’s Maglev ‘Silencer’ Could Rewrite the Rules of Ultra-Fast Travel”