Current status and trends in the development of inspection technologies and equipment for heavy-haul railway infrastructure

This paper aims to systematically review the evolution of inspection technologies and equipment for heavy-haul railway infrastructure, with a focus on China’s Shuohuang Railway and Daqin Railway. It summarizes the technological progression from traditional manual inspections to integrated and intelligent inspection systems, analyzes their practical application outcomes and outlines future research directions to support the safe, efficient and sustainable operation of heavy-haul railways.

The study employs a combination of historical and empirical analysis, primarily drawing on academic literature and operational data from Shuohuang Railway. The development of inspection technologies is categorized into two distinct phases: traditional inspection and integrated inspection. The comprehensive effectiveness of these technologies is evaluated based on actual inspection efficiency, defect detection capability, cost savings and other relevant data.

The adoption of integrated inspection vehicles has significantly improved inspection efficiency and accuracy. In 2014, the world’s first heavy-haul integrated inspection vehicle enabled synchronous multidisciplinary inspections, greatly reducing reliance on manual labor. By 2024, the intelligent heavy-haul integrated inspection vehicle further enhanced detection precision by 30%. Practical applications demonstrate that the annual number of track defects decreased from 25,000 to 3,800, while the track quality index (TQI) remained stable below 6 mm. Additionally, annual maintenance costs were reduced by more than 40 m yuan.

This paper provides the first systematic review of the development of inspection technologies for heavy-haul railway infrastructure, highlighting China’s leading achievements in integrated and intelligent inspection. It clarifies the practical value of these technologies in enhancing safety, reducing costs and optimizing maintenance operations. Furthermore, it proposes future directions for development, including system integration, onboard computing capabilities and unmanned operations, offering valuable insights for technological innovation and policymaking in the field.