China Railway Design Corporation Debuts "Acoustic Health Check" System for Subway Tunnels

China Railway Design Corporation Debuts "Acoustic Health Check" System for Subway Tunnels

TIANJIN – China Railway Design Corporation (CRDC) has unveiled a proprietary diagnostic system that can pinpoint noise and vibration sources inside subway tunnels with unprecedented precision, following a successful pilot deployment on Tianjin Metro Line 5.

Dubbed the "acoustic health check" system, the technology integrates mobile sensors, signal processing algorithms, and an integrated simulation platform to create a three-dimensional "health map" of the tunnel environment. It detects irregularities in track geometry, wheel-rail contact points, and structural resonance that contribute to excessive interior and wayside noise.

In actual field tests, the system guided engineers to install higher-performance vibration-damping fasteners at specific identified hotspots. The result: a measured noise reduction of 3 to 5 decibels at affected receptor locations, alongside a cost saving of at least 10 percent compared to conventional trial-and-error retrofitting approaches.

"Traditional methods rely on broad-spectrum mitigation, which often overshoots or misses the mark," said a CRDC R&D lead. "Our system tells you exactly where to intervene and what type of solution works best, eliminating guesswork."

Beyond noise control, the simulation platform can forecast the acoustic impact of proposed track maintenance or upgrade measures before physical implementation, significantly reducing downtime and rework costs. The company plans to commercialize the technology for urban rail operators across China, as older lines face mounting pressure to comply with tightening environmental noise standards. CRDC is also exploring integration with autonomous inspection vehicles for real-time, continuous tunnel monitoring.