Monitoring Rail Bed Infrastructure Using Wireless Passive Sensing

Details

• Creators:
  Malla, Birasa ; Ghazanfari, Ehsan ; Frolik, Jeff
• Corporate Creators:
  University of Vermont. Department of Civil and Environmental Engineering ; University of Maine. Transportation Infrastructure Durability Center (TIDC)
• Corporate Contributors:
  United States. Department of Transportation. University Transportation Centers (UTC) Program ; United States. Department of Transportation. Office of the Assistant Secretary for Research and Technology
• Subject/TRT Terms:
  Ballast Fouling Harmonic Transponder Passive Sensor Rail Bed Monitoring
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final Report
• Corporate Publisher:
  University of Maine. Transportation Infrastructure Durability Center (TIDC)
• Abstract:
  Railroad ballast plays a critical role in distributing train loads, maintaining track stability, and ensuring proper drainage. Over time, intrusion of fines and moisture leads to ballast fouling, which can compromise track structural integrity and service life. Early detection of ballast fouling is therefore essential for effective maintenance and extending the operational life of rail infrastructure. This study investigated the use of passive harmonic transponders as a low-cost, sustainable, and long-lasting sensing solution for monitoring ballast conditions. Laboratory experiments were conducted using clean and fouled ballast under varying moisture levels and transponder embedment depths. The harmonic transponder is unique in that it returns a signal at twice the frequency of that which interrogates it, allowing clear separation of the transponder response from background reflections and noise. Two types of harmonic transponders, one is commercially available sensing device (RECCO, operated at fundamental frequency 890 MHz) and another university developed sensing device (developed by Czech Technical University, operated at 1.17 GHz), were tested to evaluate signal responses under different conditions. The results indicate that moisture content and embedment depth are the primary factors influencing signal attenuation, while fouling level plays a secondary role. The transponders operated at lower frequency demonstrated more stable performance, whereas the device operated at higher frequency was more sensitive to ballast heterogeneity and moisture fluctuations. The findings suggest that embedding passive harmonic transponders during new rail-bed construction can provide a built-in monitoring system capable of early fouling detection. Interrogation of the embedded transponders can be performed using portable units, moving trains, or drones, offering a flexible and non-destructive approach. Their low-cost and passive design eliminates the need for batteries or continuous power supply, reducing both maintenance requirements and environmental impact. This energy-efficient operation enables long-term field deployment with minimal resource consumption. As a result, harmonic transponders represent a practical and sustainable solution for continuous monitoring of fouling in railway ballast.
• Format:
  PDF
• Funding:
  69A3551847101
• Collection(s):
  University Transportation Centers
• Main Document Checksum:
  urn:sha-512:3bd2f13c83b63302b5a5d3303337dfc70ef832197e65a3039e62754832950ecf76049d1b9ae4545871edb2acf9999e07da33412da378b17a042ef163d68abdc0
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/88731/dot_88731_DS1.pdf
• File Type:
  [PDF - 11.51 MB ]