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Major Results of Research and Development in Fiscal 2025

This publication is a collection of the major results obtained from research undertaken by the Japanese public body, the Railway Technology Research Institute, in 2025. We would like to take this opportunity to thank all JR companies in particular and all the research centers, universities, industrial partners and other entities which have offered their cooperation, commitment and support to achieve these results and without whom none of this work would have been possible.

Ⅰ. Improvement of Safety

1. Railway Earthquake Disaster Prevention Method Using Distributed Acoustic Sensing (DAS)

  • A method has been developed to capture the distribution of earthquake ground motion at intervals of several tens of meters, as well as a method for estimating seismic parameters, using Distributed Acoustic Sensing (DAS) technology that leverages existing telecommunications optical fiber cables.
  • This technology can improve the accuracy of earthquake early warnings and support the early resumption of railway operations, thereby enhancing railway safety during earthquakes and reducing downtime.

  • A method has been developed to capture the distribution of earthquake ground motion at intervals of several tens of meters, as well as a method for estimating seismic parameters, using Distributed Acoustic Sensing (DAS) technology that leverages existing telecommunications optical fiber cables.
  • This technology can improve the accuracy of earthquake early warnings and support the early resumption of railway operations, thereby enhancing railway safety during earthquakes and reducing downtime.

2. Real-Time Spatial Earthquake Motion Estimation Using Machine Learning

  • To improve the accuracy of the Damage Information System for Earthquake on Railway (DISER), a method has been developed that incorporates machine learning for spatial interpolation of bedrock motion and estimation of vibration characteristics of ground.
  • By improving the estimation accuracy of earthquake motion values by approximately 10% on average nationwide and by up to 30% in some areas, the method enables more accurate decision-making on post-earthquake operation resumption and further reduces service recovery time.

  • To improve the accuracy of the Damage Information System for Earthquake on Railway (DISER), a method has been developed that incorporates machine learning for spatial interpolation of bedrock motion and estimation of vibration characteristics of ground.
  • By improving the estimation accuracy of earthquake motion values by approximately 10% on average nationwide and by up to 30% in some areas, the method enables more accurate decision-making on post-earthquake operation resumption and further reduces service recovery time.

3. Enhancement of Seismic Train-Running Safety on Viaducts Using Low-Cost Displacement-Suppression Dampers

  • A new displacement suppression damper for viaducts that can improve vehicle running safety during earthquakes has been developed.
  • The developed damper consists solely of combinations of standard steels and simple machining processes. By eliminating the need for special processing, it achieves more than 20% cost reduction compared with conventional dampers while also enabling faster installation.
  • The developed damper is also expected to increase the earthquake motion threshold for derailment by more than 50%.

  • A new displacement suppression damper for viaducts that can improve vehicle running safety during earthquakes has been developed.
  • The developed damper consists solely of combinations of standard steels and simple machining processes. By eliminating the need for special processing, it achieves more than 20% cost reduction compared with conventional dampers while also enabling faster installation.
  • The developed damper is also expected to increase the earthquake motion threshold for derailment by more than 50%.

4. Elucidation of Air Spring Behavior Under Large Displacements and Abnormal Conditions

  • Tests conducted under large displacement conditions confirmed the nonlinear response and leakage behavior of air springs.
  • Based on the test results, we proposed an analytical model capable of reproducing air spring behavior under large displacement and abnormal conditions.
  • The proposed air spring model was incorporated into a previously developed vehicle behavior simulation program, enabling more realistic evaluation of dynamic vehicle behavior during earthquakes.

  • Tests conducted under large displacement conditions confirmed the nonlinear response and leakage behavior of air springs.
  • Based on the test results, we proposed an analytical model capable of reproducing air spring behavior under large displacement and abnormal conditions.
  • The proposed air spring model was incorporated into a previously developed vehicle behavior simulation program, enabling more realistic evaluation of dynamic vehicle behavior during earthquakes.

5. Multifunctional Experiment Facility and Prediction Method for Hot Gas Layer Characteristics in Tunnel Fires

  • A multifunctional experimental facility for tunnel fires, capable of reproducing the heat absorption characteristics of full-scale tunnel linings has been developed.
  • The effects of vehicles, branch tunnels, tunnel gradients, and wind on the propagation of the hot gas layer were investigated.
  • Simplified equations were proposed for rapidly estimating the temperature, propagation speed, and thickness of the hot gas layer.

  • A multifunctional experimental facility for tunnel fires, capable of reproducing the heat absorption characteristics of full-scale tunnel linings has been developed.
  • The effects of vehicles, branch tunnels, tunnel gradients, and wind on the propagation of the hot gas layer were investigated.
  • Simplified equations were proposed for rapidly estimating the temperature, propagation speed, and thickness of the hot gas layer.

6. Granular Flame Retarder for Railway Seats Using a Self-Extinguishing Resin for Reducing Fire Risk

  • To reduce the fire risk associated with railway seats, which account for a large proportion of the combustible materials in railway vehicles, a granular flame retarder using a self-extinguishing resin that can be applied to seat cushion materials has been developed.
  • Combustion testing of a prototype seat containing the granular flame retarder demonstrated that heat release during the early stage of combustion was reduced by about half of that of a conventional seat.

  • To reduce the fire risk associated with railway seats, which account for a large proportion of the combustible materials in railway vehicles, a granular flame retarder using a self-extinguishing resin that can be applied to seat cushion materials has been developed.
  • Combustion testing of a prototype seat containing the granular flame retarder demonstrated that heat release during the early stage of combustion was reduced by about half of that of a conventional seat.

Ⅱ. Improvement of Productivity

7. Fretting Wear Mitigation Method for Axle Journal Bearings

  • A wear mitigation method was developed without requiring major design modifications or additional components.
  • Active duty car tests confirmed the effectiveness of the proposed method up to approximately 550,000 km, while bench rotation tests demonstrated its long-term durability, equivalent to approximately 1.2 million km of running distance.
  • The method enables the extension of inspection intervals for railway vehicles, thereby reducing maintenance labor requirements.

  • A wear mitigation method was developed without requiring major design modifications or additional components.
  • Active duty car tests confirmed the effectiveness of the proposed method up to approximately 550,000 km, while bench rotation tests demonstrated its long-term durability, equivalent to approximately 1.2 million km of running distance.
  • The method enables the extension of inspection intervals for railway vehicles, thereby reducing maintenance labor requirements.

8. Construction, Inspection, and Reinforcement Methods for Preventing Fracture of Aluminothermic Weldings

  • For application to Shinkansen tracks, an aluminothermic welding method that improves bending fatigue strength by more than 20% has been developed, along with inspection and reinforcement methods capable of preventing weld fractures caused by solidification cracking.
  • This method improves the reliability of welded joints, which is essential for stable railway operations, and reduces both labor requirements and costs by approximately 30% compared with the current welding method, which relies on highly skilled workers.

  • For application to Shinkansen tracks, an aluminothermic welding method that improves bending fatigue strength by more than 20% has been developed, along with inspection and reinforcement methods capable of preventing weld fractures caused by solidification cracking.
  • This method improves the reliability of welded joints, which is essential for stable railway operations, and reduces both labor requirements and costs by approximately 30% compared with the current welding method, which relies on highly skilled workers.

9. Rail Head Transverse Crack Detection using Guide Waves

  • We have developed a non-contact crack detection system using guide waves that can replace the manual ultrasonic inspection previously required to detect rail head transverse cracks which could not be detected by conventional inspection vehicles.
  • By transmitting and receiving guide waves from the rail head top and side, the system can detect transverse cracks beneath horizontal cracks, regardless of horizontal crack length, reducing the effort required for conventional transverse crack inspection.

  • We have developed a non-contact crack detection system using guide waves that can replace the manual ultrasonic inspection previously required to detect rail head transverse cracks which could not be detected by conventional inspection vehicles.
  • By transmitting and receiving guide waves from the rail head top and side, the system can detect transverse cracks beneath horizontal cracks, regardless of horizontal crack length, reducing the effort required for conventional transverse crack inspection.

10. Automation of Spalling Condition Assessment Using Hammering Sound Judgment AI and Hammer Auto-tracking

  • A system was developed that projects AI-derived heatmaps of deformations and hammering necessity levels onto tunnel walls.
  • The system can automatically record hammering locations and AI judgment results.
  • Using this information, the system can automatically assess spalling conditions and reduce the manpower required for tunnel inspections.

  • A system was developed that projects AI-derived heatmaps of deformations and hammering necessity levels onto tunnel walls.
  • The system can automatically record hammering locations and AI judgment results.
  • Using this information, the system can automatically assess spalling conditions and reduce the manpower required for tunnel inspections.

11. Embankment Quality Control Methods Using Construction Phase Settlement Data

  • A quality control method for embankments using settlement data obtained during construction phase was proposed.
  • The use of ICT equipment enables settlement data to be acquired easily and on an area-wide basis.
  • The proposed method reduces the time required for quality control measurements by approximately 90% and labor requirements by approximately 40%.

  • A quality control method for embankments using settlement data obtained during construction phase was proposed.
  • The use of ICT equipment enables settlement data to be acquired easily and on an area-wide basis.
  • The proposed method reduces the time required for quality control measurements by approximately 90% and labor requirements by approximately 40%.

12. Damage Estimation and Visualization Tool for Signaling Facilities Affected by Snow Dropping from High-Speed Vehicles

  • A method for estimating damage to signaling facilities caused by snow dropping has been developed.
  • We developed an application tool that displays sections where snow dropping damage is likely, estimated using weather information, and lists the signaling facilities located within those sections.

  • A method for estimating damage to signaling facilities caused by snow dropping has been developed.
  • We developed an application tool that displays sections where snow dropping damage is likely, estimated using weather information, and lists the signaling facilities located within those sections.

13. Marker-Assisted Platform Position Measurement Using Forward-View Train Images

  • A method was developed to automatically measure the height and lateral gap of station platforms relative to the rail from forward-view train images using dedicated ground markers.
  • The method can measure the lateral gap with an accuracy of approximately 10 mm, enabling more efficient station platform measurements and management.

  • A method was developed to automatically measure the height and lateral gap of station platforms relative to the rail from forward-view train images using dedicated ground markers.
  • The method can measure the lateral gap with an accuracy of approximately 10 mm, enabling more efficient station platform measurements and management.

14. Anomaly Screening Method for Overhead Contact Line Equipment Requiring High-Frequency Inspection

  • We extended a previously developed anomaly screening method for overhead contact line (OCL) equipment and developed an image analysis method that automates approximately 90% of high-frequency inspections.
  • Image processing tailored to the geometry of overhead contact line equipment streamlines the review of flagged anomalous images.

  • We extended a previously developed anomaly screening method for overhead contact line (OCL) equipment and developed an image analysis method that automates approximately 90% of high-frequency inspections.
  • Image processing tailored to the geometry of overhead contact line equipment streamlines the review of flagged anomalous images.

15. Method for Identifying Causes of Failures in Electric Point Machines

  • Measurement items required for identifying failure causes including motor current were selected, and a method has been developed for remotely identifying faulty components and their causes immediately after switching failures occur.
  • This enables rapid remote identification of causes and the arrangement of necessary restoration equipment, thereby reducing restoration time.

  • Measurement items required for identifying failure causes including motor current were selected, and a method has been developed for remotely identifying faulty components and their causes immediately after switching failures occur.
  • This enables rapid remote identification of causes and the arrangement of necessary restoration equipment, thereby reducing restoration time.

16. Performance Evaluation Method for Inspection Systems Using Cameras and Sensors Based on CG Simulation

  • A method was developed to use CG simulation to verify in advance the performance of various inspection systems and algorithms using cameras and sensors.
  • This method enables evaluation without field tests, even under conditions that are difficult to reproduce in practice, such as changes in weather.
  • The method can be used for hardware selection of inspection systems, sensor layout design, and algorithm evaluation.

  • A method was developed to use CG simulation to verify in advance the performance of various inspection systems and algorithms using cameras and sensors.
  • This method enables evaluation without field tests, even under conditions that are difficult to reproduce in practice, such as changes in weather.
  • The method can be used for hardware selection of inspection systems, sensor layout design, and algorithm evaluation.

17. Method for Constructing 3D Railway Track Spatial Data Using In-service Trains

  • A method was developed for constructing highly realistic 3D spatial data of railway tracksides from images captured by commercially available video cameras installed in the cab of in-service trains.
  • The method enables the positions and shapes of trackside facilities to be mapped without using expensive inspection vehicles.
  • The method was validated on an actual railway track, and its applicability to visibility inspections of signal devices was confirmed.

  • A method was developed for constructing highly realistic 3D spatial data of railway tracksides from images captured by commercially available video cameras installed in the cab of in-service trains.
  • The method enables the positions and shapes of trackside facilities to be mapped without using expensive inspection vehicles.
  • The method was validated on an actual railway track, and its applicability to visibility inspections of signal devices was confirmed.

18. Safety Confirmation-Based Train Control System

  • To reduce maintenance costs for regional railways, a train control system utilizing public communication networks was developed to ensure safe operation even in the event of communication interruption.
  • By standardizing system functions, on-board and ground equipment from different vendors can be used within the same system.

  • To reduce maintenance costs for regional railways, a train control system utilizing public communication networks was developed to ensure safe operation even in the event of communication interruption.
  • By standardizing system functions, on-board and ground equipment from different vendors can be used within the same system.

19. Comprehension Visualization System for Trainees in Remote Lectures for Driver Training

  • A method was developed to quantitatively evaluate “remote affinity,” which indicates how suitable each subject is for remote lectures in classroom training for driver certification.
  • A system was also developed to visualize trainees' comprehension, which is difficult to assess in remote lectures, and to provide an alert function that gives early warnings of declining comprehension based on remote affinity.

  • A method was developed to quantitatively evaluate “remote affinity,” which indicates how suitable each subject is for remote lectures in classroom training for driver certification.
  • A system was also developed to visualize trainees' comprehension, which is difficult to assess in remote lectures, and to provide an alert function that gives early warnings of declining comprehension based on remote affinity.

Ⅲ. Harmonization with the Environment

20. Degradation Prediction Method for Traction Lithium-Ion Batteries

  • A degradation prediction method was developed for traction lithium-ion batteries subject to frequent charging and discharging, and its prediction accuracy was verified by comparison with real vehicle data.
  • This method enables the prevention of premature battery replacement and reduces replacement costs, thereby promoting the deployment of battery-powered vehicles.

  • A degradation prediction method was developed for traction lithium-ion batteries subject to frequent charging and discharging, and its prediction accuracy was verified by comparison with real vehicle data.
  • This method enables the prevention of premature battery replacement and reduces replacement costs, thereby promoting the deployment of battery-powered vehicles.

21. CO2 Emissions Calculation Method for Rail Freight Transport

  • A method was developed for estimating CO2 emissions from long-distance freight trains with an accuracy of approximately 10%, considering operating conditions such as the timetables and routes of trains.
  • By estimating and summing energy losses such as running resistance and braking, this method calculates CO2 emissions simply and accurately, even on a nationwide scale.

  • A method was developed for estimating CO2 emissions from long-distance freight trains with an accuracy of approximately 10%, considering operating conditions such as the timetables and routes of trains.
  • By estimating and summing energy losses such as running resistance and braking, this method calculates CO2 emissions simply and accurately, even on a nationwide scale.

22. Geopolymer Concrete Containing By-products from Shinkansen Rolling Stock as Raw Materials

  • A geopolymer concrete containing by-products generated during the recycling and reuse of aluminum from Shinkansen rolling stock as admixtures has been developed.
  • A prototype railway sleeper was manufactured and confirmed to meet the performance requirements of the JIS standard.

  • A geopolymer concrete containing by-products generated during the recycling and reuse of aluminum from Shinkansen rolling stock as admixtures has been developed.
  • A prototype railway sleeper was manufactured and confirmed to meet the performance requirements of the JIS standard.

23. Method for Assessing Train Set-specific Wheel Tread Conditions Using Continuous Remote Monitoring of Wayside Noise

  • A monitoring method has been developed to enable continuous measurement of wayside noise at locations such as evaluation points 25 m from the near-side track, points directly beneath viaducts, and points near the rail.
  • Since temporal changes in rolling noise reflecting wheel tread conditions can be monitored remotely, the method can be used from an environmental conservation perspective to help determine the optimal wheel reprofiling timing for each train set.

  • A monitoring method has been developed to enable continuous measurement of wayside noise at locations such as evaluation points 25 m from the near-side track, points directly beneath viaducts, and points near the rail.
  • Since temporal changes in rolling noise reflecting wheel tread conditions can be monitored remotely, the method can be used from an environmental conservation perspective to help determine the optimal wheel reprofiling timing for each train set.

Ⅳ. Improvement of Convenience

24. High-Strength Shinkansen Contact Wire Splice for Emergency Restoration after Disasters

  • A splice for the emergency restoration of Shinkansen high-strength contact wires following disasters has been developed.
  • In-house tests demonstrated that the splice can be applied for train passing speeds of up to 200 km/h.
  • The splice enables the current 110 km/h speed restriction imposed during post-disaster emergency restoration to be relaxed.

  • A splice for the emergency restoration of Shinkansen high-strength contact wires following disasters has been developed.
  • In-house tests demonstrated that the splice can be applied for train passing speeds of up to 200 km/h.
  • The splice enables the current 110 km/h speed restriction imposed during post-disaster emergency restoration to be relaxed.

25. Method for Estimating Station Passenger Volumes on Regional Railways

  • A method was developed to estimate the numbers of boarding and alighting passengers at regional railway stations with improved accuracy by combining crew-reported passenger count data collected by railway operators with boarding and alighting survey data collected on-site over several days.
  • Compared with the conventional method based on monthly ticket sales data, the proposed method reduced estimation error by 66% using five days of passenger survey data, making it useful for planning feeder transport services and supporting investment decisions for station facilities.

  • A method was developed to estimate the numbers of boarding and alighting passengers at regional railway stations with improved accuracy by combining crew-reported passenger count data collected by railway operators with boarding and alighting survey data collected on-site over several days.
  • Compared with the conventional method based on monthly ticket sales data, the proposed method reduced estimation error by 66% using five days of passenger survey data, making it useful for planning feeder transport services and supporting investment decisions for station facilities.

26. Method for Automatically Generating Train Rescheduling Plans to Minimize the Number of Delayed Passengers

  • A method was developed to automatically generate train rescheduling plans during disruptions to train services while taking passenger impacts into account (a case study of a double-track commuter line with passing tracks, without train service cancellations).
  • The proposed method can generate train rescheduling plans within two minutes that result in a number of delayed passengers comparable to that achieved by an experienced dispatcher, enabling labor savings and reducing reliance on dispatcher expertise in train rescheduling.

  • A method was developed to automatically generate train rescheduling plans during disruptions to train services while taking passenger impacts into account (a case study of a double-track commuter line with passing tracks, without train service cancellations).
  • The proposed method can generate train rescheduling plans within two minutes that result in a number of delayed passengers comparable to that achieved by an experienced dispatcher, enabling labor savings and reducing reliance on dispatcher expertise in train rescheduling.

Ⅴ. Basic Research

27. Method for Evaluating Erosion on Embankment Slopes Induced by Rainfall

  • An erosion test apparatus capable of simulating embankment erosion caused by surface water was developed, and a method for quantitatively evaluating erosion of embankment slopes was proposed using the apparatus in combination with erosion analysis.
  • The proposed method can be applied to the planning of preventive measures for existing embankments against heavy rainfall, as well as to material selection in the design of steepened embankments.

  • An erosion test apparatus capable of simulating embankment erosion caused by surface water was developed, and a method for quantitatively evaluating erosion of embankment slopes was proposed using the apparatus in combination with erosion analysis.
  • The proposed method can be applied to the planning of preventive measures for existing embankments against heavy rainfall, as well as to material selection in the design of steepened embankments.

28. Snow Accretion Simulation Based on a Constitutive Law for Snow Throwing by Wheels

  • The mechanism of snow throwing by wheels was elucidated, and a constitutive law that can represent this phenomenon was developed.
  • The developed constitutive law was implemented in an existing snow accretion simulator enabling the analysis of ice-type snow accretion.
  • The findings can be applied to the design of snow accretion prevention structures for railway vehicles and to the prediction of a countermeasure's effectiveness.

  • The mechanism of snow throwing by wheels was elucidated, and a constitutive law that can represent this phenomenon was developed.
  • The developed constitutive law was implemented in an existing snow accretion simulator enabling the analysis of ice-type snow accretion.
  • The findings can be applied to the design of snow accretion prevention structures for railway vehicles and to the prediction of a countermeasure's effectiveness.

29. Simulation Method for Impact Response of Track Members under Wheel Flat Conditions

  • A numerical simulation method capable of quantitatively evaluating the impact response of track members such as sleepers induced by the passage of vehicles with wheel flats was developed.
  • This method can be applied to the design of PC sleepers according to line-specific conditions, the quantification of the effects of introducing high-performance materials such as low-stiffness rail pads, and as a tool for clarifying the causes of PC sleeper fracture.

  • A numerical simulation method capable of quantitatively evaluating the impact response of track members such as sleepers induced by the passage of vehicles with wheel flats was developed.
  • This method can be applied to the design of PC sleepers according to line-specific conditions, the quantification of the effects of introducing high-performance materials such as low-stiffness rail pads, and as a tool for clarifying the causes of PC sleeper fracture.

30. Mechanism of Lift Force Variation in Shinkansen Pantograph Heads

  • The mechanism by which changes in the cross-sectional shape of the pantograph head affect lift force characteristics has been clarified.
  • A predictive formula was proposed for estimating changes in lift force caused by variations in the inclination angle of the frontal surface of the pantograph head, and the range of shape parameters that prevent large lift force variations due to contact strip wear was clarified.
  • This can be utilized to improve the efficiency of pantograph head development and to prevent failures caused by lift force.

  • The mechanism by which changes in the cross-sectional shape of the pantograph head affect lift force characteristics has been clarified.
  • A predictive formula was proposed for estimating changes in lift force caused by variations in the inclination angle of the frontal surface of the pantograph head, and the range of shape parameters that prevent large lift force variations due to contact strip wear was clarified.
  • This can be utilized to improve the efficiency of pantograph head development and to prevent failures caused by lift force.

31. Knee Impact Test to Assess Driver Injury Risk in Train Accidents

  • A knee impact test capable of accurately estimating driver thigh injury values was proposed.
  • A numerical analysis model capable of highly accurately reproducing both human body model tests and knee impact tests has been developed.
  • This can be applied to the design of cab specifications and the evaluation of damage mitigation measures.

  • A knee impact test capable of accurately estimating driver thigh injury values was proposed.
  • A numerical analysis model capable of highly accurately reproducing both human body model tests and knee impact tests has been developed.
  • This can be applied to the design of cab specifications and the evaluation of damage mitigation measures.

•A part of I.1 was accomplished by Railway Technology Development Subsidy of Ministry of Land, Infrastructure, Transport and Tourism.
•A part of I.1 was conducted as collaborative research with Japan Agency for Marine-Earth Science and Technology, National Research Institute for Earth Science and Disaster Resilience and East Japan Railway Company.
•A part of I.5 was conducted as collaborative research with Yokohama National University.
•I.6 was conducted as collaborative research with ADEKA Corporation.
•A part of II.7 was conducted as collaborative research with NSK Ltd. and JTEKT Corporation.
•II.10 was accomplished by Transportation Technology Development Promotion System of Ministry of Land, Infrastructure, Transport and Tourism, Grant Number JPJ002223.
•II.13 was conducted as collaborative research with Shikoku Railway Company.
•A part of II.14 was conducted as collaborative research with Shizuoka University and Meidensha Corporation.
•A part of II.15 was conducted as collaborative research with Kyosan Electric Mfg. Co., Ltd.
•A part of II.16 was conducted as collaborative research with Meidensha Corporation.
•A part of II.18 was conducted as collaborative research with Kyosan Electric Mfg. Co., Ltd., NIPPON SIGNAL CO., LTD., Hitachi, Ltd. and Daido Signal Co., Ltd.

Major Results of Research and Development