Major Results of Research and Development in Fiscal 2015

This publication is a collection of the major results obtained from research undertaken by the Japanese public body, the Railway Technology Research Institute, in 2015.
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. Advanced seismograph for earthquake early warnings

  • A seismograph was developed to issue earthquake early warnings, offering more accurate seismic parameter estimation and timing, and improved noise discrimination functions.
  • The new advanced seismograph makes it possible to cut the time between warnings being issued to the arrival of seismic motion, by one second.
  • Noise discrimination was improved by 7.4% compared to existing devices.

2.Method for extracting vulnerable structures during earthquakes

  • A method for identifying vulnerable structures on long-distance lines has been proposed, where the running safety of trains can be compromised.
  • This method does not require large scale measurements or surveys and can be used with simple data found in design documents, drawings and specifications.
  • In cases of tall structures on stiff ground, it was possible to improve accuracy of estimated damping by over 50%.
  • The proposed method indicates the supplemental damping required to assure the running safety of trains.

3.Seismic reinforcement technology for earth retaining walls in narrow locations

  • A technique has been developed to adapt natural ground seismic reinforcement measures to steeper and narrower locations
  • Confirmation was obtained that the present reinforcement method doubles seismic resistance
  • A design manual was produced containing all the methods for selecting which kind of seismic reinforcement measure to apply to earth retaining walls

4. Method for assessing tsunami damage to concrete bridges

  • A method has been proposed to calculate the fluid forces acting on concrete bridges, from tsunamis
  • A method has been proposed to assess tsunami damage to bridge piers and concrete girder outflow
  • The assessment and calculation methods can be used to design girder outflow prevention work and bridge pier reinforcement against tsunamis.

5. Management of snowmelt for landslide prevention

  • This method can be used to predict critical periods during the snowmelt season, using meteorological data to estimate run-off volume from snowmelt to evaluate the safety of slopes.
  • A surveying method is proposed using topographical and ground condition data to identify vulnerable landslide prone locations.

6. Calculation of the aerodynamic coefficient on trains in half-bank half-cut line sections

  • A quantitative evaluation was made of the aerodynamic coefficient of trains on half-bank half-cut sections of line
  • For winds acting at an angle of 90 degrees on intermediate carriages, it was observed that running safety was higher with cut banks of a height of 10 m or half-bank half-cut embankments of 15 m.
  • A proposal was made to use the aerodynamic coefficient as an indicator for evaluating safety in high winds on sections with half-bank half-cut embankments.

7. Revision of evaluation criteria to check deterioration in lubricating grease used on trains

  • The values used in criteria applied for managing the grease used in axle boxes and traction motors have been revised.
  • Lithium complex soap grease is used for lubricating traction motors on approximately 80% of conventional line trains. A new indicator has been proposed for the thermal tolerance of this grease to replace ‘changes in dropping point value’.
  • New criteria values have been proposed as the new standard for evaluating deterioration in the grease.

8.Method for detecting step-shaped wear on contact strips on pantograph heads

  • In order to prevent damage to overhead contact lines, a method for detecting step-shaped wear on contact strips on pantographs has been developed. In addition, a data acquisition device suited to this method has also been developed.
  • RTRI then drafted some technical recommendations for railway operators on the practical application of the system.

9.Improving lightening resistance of electrical equipment using new grounding structure

  • A new grounding structure was developed to improve the lightening resistance of electrical equipment.
  • Compared to existing structures, the potential-rise due to lightning strikes is reduced by approximately 50% and voltage difference by about 60%, cutting the frequency of estimated lightning damage by approximately 20%.

10.Proposal of method for diagnosing health of concrete masts for maintenance

  • Through surveys on the health of concrete masts, conducting bending strength tests and materials analyses, insight was obtained into the processes involved in concrete mast deterioration.
  • A new method was subsequently proposed to diagnose the health of concrete masts.

11.On-board platform detection device to assist train crew in train door operation

  • A device was developed to identify which side of the train the platform is on by image detection of the train stopping position signs.
  • By adding gyro-sensor and GPS functions, the platform can be detected in over 90% cases even when covered in snow.
  • A device was proposed to assist on board staff operating train doors.

12.Human factor analysis method using Potential Incidents Reports

  • A method has been proposed to improve the effectiveness of analyses conducted using the RTRI Human Factor Analysis method
  • Employing Potential Incidents Reports to promote better organizational and work systems.

Ⅱ. Harmonization with the Environment

13.Sheet pile reinforcement work on pile foundations during ground liquefaction

  • A reinforcement technique has been developed using the addition of steel sheet piles with closed sections at the bottom to existing pile foundations during ground liquefaction.
  • Confirmation was obtained that this new technique can reduce the working load on existing pile foundations by 30%, and a guide to use of the technique was compiled.
  • This reinforcement technique costs approximately 20% less to apply than existing methods.

14.Countermeasure for fatigue cracks around I-beam bridge supports

  • A method has been developed to repair fatigue cracks around I-beam bridge supports by covering the end of the girder with concrete.
  • The method can be applied to most I-beam bridges which have a span of less than 7 m.
  • The repairs can be completed quickly, and represent approximately 1/3 of the cost of replacing the bridge.

15.Countermeasure work on ballasted Shinkansen track to prevent ballast migration

  • Ballast migration on a ballasted Shinkansen track was reproduced by vibration machine, producing insight into the mechanisms leading to this phenomenon.
  • A countermeasure was developed using biodegradable aqueous polymer solution to stabilize the ballast on the track.
  • This measure manages to reduce costs by 50%, and allows tamping work to be conducted after the procedure.

16.Method for detecting damage and repairing slab track cement asphalt mortar layers

  • A method has been proposed to use track inspection data to detect damaged sections in the CA mortar layer under slab track.
  • A method for repairing the gaps in the upper CA mortar layer was developed, which reduces material costs by 40% compared to existing renovation methods.
  • A method was then developed to carry out repairs on large-scale damage to the CA mortar layer. This new renovation method reduces costs by 50% compared to present methods which completely replace the CA mortar layer.

17.Decision-making support system for planning replacement of wooden-sleepers with PC sleepers in curved sections

  • A system has been developed to help plan replacement of wooden sleepers with PC sleepers according to the specific characteristics of each curved section, its track structure, rolling stock and operating conditions.
  • This system can also be used to calculate the most appropriate distribution of PC and wooden sleepers when carrying out partial replacement work.
  • By using the system, it is possible to reduce the length of curves requiring replacement of wooden sleepers with PC sleepers by approximately 15% compared to taking curves in order of radius size starting from the smallest.

18.System for inspecting obstruction warning signals

  • Using image processing technology, a system for inspecting Obstacle Warning Signals has been developed.
  • By applying the new system, signals can be inspected during daytime operating hours, thus reducing the inspection time to 30% of the existing method, according to estimations on a model line.

19.Possibility of practical application of a 920MHz bandwidth network

  • It has been demonstrated through experiments that wireless network technology using a 920MHz frequency band has the potential for broad application in the monitoring of railway infrastructure and equipment, such as structures and railway vehicles.
  • This type of network is unaffected by weather conditions and is capable of successfully transmitting over 95% of various kinds of data.

Ⅲ. Cost Reduction

20.Characteristics of long-term fuel cell deterioration

  • Before introducing fuel cells onto trains, their endurance for long-term use be tested through 3600 train runs and ten years of power generation tests.
  • This paper proposes new fuel cell design guidelines based on risk assessments in the light of defect reports.

21.Quantification of impact noise due to local wear on wheel treads on Shinkansen railway noise, and method for detecting local wear.

  • A quantitative investigation was made into the effect of impact noise due to local wear on wheel treads, on Shinkansen railway noise.
  • A method has been developed for detecting local wear above 0.1mm on wheel treads from vibrations induced on viaducts.
  • This method can contribute greatly to detecting local wheel wear, which affects wayside noise.

22.Verification of High Temperature Superconducting Flywheel Storage Systems

  • A machine has been developed for verifying high-temperature superconducting flywheel storage systems with contactless flywheel support, using high-temperature superconducting magnetic bearings.
  • Confirmation was obtained using the verification equipment that a small high-temperature superconducting magnetic contactless bearing was capable of supporting a 4-ton flywheel in a system with an output power of 300kW, and storage capacity of 25kWh.

Ⅳ. Improvement of Convenience

23. Car-body tilt control system for better ride comfort

  • A control system was developed for tilting trains to mitigate motion sickness
  • The new system can reduce the motion sickness dose value in sharp curves by 30% and be installed on existing tilting trains.
  • It is proposed that the system can be installed on not only new trains but also existing tilting trains travelling through sections with successive sharp curves during their overhaul periods.

24.Design method and performance verification for linear rail brakes used on high-speed trains

  • A design method has been developed to produce contactless, compact and light-weight linear rail brakes which can still function during power cuts and can be used on high-speed trains.
  • Based on model tests and simulations, it is expected that the new model linear rail brake will be able to reduce the stopping distance after application of brakes at nearly the maximum running speed, by about 10% compared brake systems using adhesion alone.

25.Method for predicting passenger thermal comfort in railway vehicles

  • A method has been developed to predict passenger thermal comfort which correlates closely with the physiological and psychological state of passengers.
  • Subjective experiments in thermal environments were conducted in main line and commuter vehicles. Results demonstrated that the proposed prediction method reflected passenger thermal comfort accurately, with a correlation of over 0.8.

26.Training support program to foster resourcefulness when making PA announcements during disruptions

  • A training method has been proposed to encourage train conductors to be more resourceful when making PA announcements during disruptions, and a training program has been devised to support trainers when conducting on-site practice sessions.
  • After training train conductors with this method, their resourcefulness improved by approximately 20 points on the evaluation scale.
  • The method has been proposed in the form of “study support material” and “trainer and evaluation support material” for trainers.

27.Improvement of visibility of Tactile Walking Surface Indicators (TWSIs) for people with low vision

  • Investigations were conducted into suitable specifications for the continuous adjoining bands (CAB) to improve the visibility of tactile walking surface indicators (TWSIs).
  • A proposal was made to make CABs about 5-15 cm wide, with a luminance ratio of about 3, at least, when used with TWSIs.

Ⅴ. Basic Research

28.Obstacle monitoring system using 90GHz band millimeter wave

  • A new monitoring system has been proposed which combines a 90 GHz band millimeter wave not yet used in the railway environment and Radio over Fiber technology.
  • It has been confirmed that the system can detect the presence of a small group of people from a distance over 100m with a resolution of 50cm.

29.Simulation of contact between running railway vehicles and railway structures during earthquakes

  • Previously, due to unfeasible calculation times required, it was not possible to analyze contact between running railway vehicles and railway structures during earthquakes. However, a new method has now been developed with feasible calculation times to analyze such situations, in order to evaluate the effectiveness of derailment damage mitigation measures such as L-guides and vehicle guide guards during very large earthquakes.
  • The new method can be used as a tool to evaluate the effectiveness of derailment damage mitigation measures and analyze vehicle contact with railway structures in case of a derailment.

30.Aerodynamic characteristics simulation method capable of reproducing crosswind wind tunnel tests

  • A numerical flow simulation method has been developed capable of reproducing crosswind wind tunnel tests.
  • It was confirmed that the simulation method could predict the side force coefficient in wind tunnel tests within a maximum 20% error margin.
  • This simulation method can be used to narrow down certain test conditions and thereby be used as a tool to improve testing efficiency.

・Ⅰ.2, Ⅰ.4, Ⅱ.17, Ⅲ.20 received funding from the Ministry of Land, Infrastructure, Transport and Tourism. ・Ⅴ.28 received funding from the Ministry of Internal Affairs and Communications. ・Ⅲ.22 received a grant from the New Energy and Industrial Technology Development Organization(NEDO). ・Ⅱ.19 is the result of research “Research and Development on Fundamental and Utilization Technologies for Social Big Data” sponsored by the National Institute of Information and Communications Technology.