Major Results of Research and Development in Fiscal 2016

This publication is a collection of the major results obtained from research undertaken by the Japanese public body, the Railway Technology Research Institute, in 2016.
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. Effectiveness of embankment slope work against cloudbursts

  • Insight was gained into the embankment failure mechanisms particularly associated with short, heavy downpours.
  • Embankment slope work increased resistance to precipitation by a factor of 1.3.
  • These findings can be applied to embankment slopes as a countermeasure to cloudbursts.

2. Development of seismic reinforcement methods for bridge abutment and proposal for new design method

  • A new seismic reinforcement method for bridge abutments was developed which does not encumber the space in front of abutments.
  • A seismic design method adapted to level 2 earthquake motion was proposed.
  • It was confirmed that the new method more than doubles resistance to earthquake motion compared to bridge abutments without reinforcement.

3. Fracturing grouting as a countermeasure against soil liquefaction

  • A method was developed to densify ground against soil liquefaction using grout injection.
  • The volume of injected material was cut by 1/3, reducing cost and work time.
  • This method was found to be a suitable countermeasure against soil liquefaction directly under existing railway embankments.

4. Anti-seismic measures using a vibration control damper

  • A design method for a vibration control device has been developed for work on difficult structures, such as bridge piers constructed in rivers.
  • Using the proposed design drawing, the effectiveness of the vibration control can be estimated to within an error margin of approximately 10% .
  • Guidelines including some numerical examples have been proposed to assist application of the vibration control device in design work.

5. Bogie designed to prevent flange climb derailment

  • A bogie designed to improve safety by preventing flange climb derailment was developed combining a bogie designed to suppress wheel load decrease and steering assistance.
  • Based on the derailment quotient used to determine the level of safety against flange climb derailment in curved section, the newly developed bogie showed a performance improvement of 60% compared to ordinary bogies.

6. Method for evaluating running safety in case of punctured air spring

  • A method for evaluating vehicle running safety in case of punctured air spring based on wheel lift was proposed.
  • This method will allow railway operators to make a preliminary assessment based on curve parameters, of running safety in the case of a punctured air spring, before driving the train back to its shed, or engaging in break down assistance, in order to identify sections requiring particular caution.

7. Wireless communication network for monitoring of freight car condition

  • A system using a 920MHz band has been proposed, in response to the need for information about the status of each freight car in a consist when train compositions are changed; the system automatically composes the network and sends it to the driver’s cab on the locomotive.
  • This system is able to check the state of a freight car’s hand brake in approximately half the time required for a visual inspection, and can also be used to monitor freight car conditions.

8. Development of a deterrent sound to prevent Deer-Train Collisions

  • A deterrent sound including the alarm call of deer has been designed to prevent deer-train collisions.
  • Emission of the deterrent sound from a train resulted in a 45% reduction in the frequency deer being observed.
  • A method has been designed to select sections where the deterrent sound should be sounded, using the collision map created with the GIS.

9. Training material to prevent communication errors

  • A “Communication error causation model” gathering error factors obtained through incident and accident analyses was designed.
  • Practical training material was prepared to respond to railway operation related communication errors.

Ⅱ.Cost Reduction

10. Design method for concrete filled tube members with rectangular section

  • A method was proposed to estimate the flexural capacity and deformation performance of rectangular CFT members.
  • The cross section of rectangular CFT members can be made up to 30% smaller than other existing members.
  • Improving the connectivity of these members to building columns in station buildings etc. can reduce construction costs for connection work by 10%.

11. Tunnel lining crack detection method using deep learning or multi-layer neural network

  • A method for detecting cracks in tunnel linings has been developed using multi-layer neural networks offering over 90% successful detection.
  • The method’s discernment capability is close to that of a human being, allowing automatic generation of maps showing damage progression.

12. Methods to detect and predict rapid localized deterioration of track irregularity

  • An effective method has been developed to correct the position of track irregularity waveforms with an accuracy of ± 25cm along the railway track, by comparing frequently measured track irregularity waveforms.
  • By computing the difference between the corrected waveforms, rapid deterioration of local track irregularity can be detected. After this, a method to predict changes of ±1mm, up to fifteen days ahead, was developed.

13. Development of new solid-bed track with resilient sleepers using shear-key to achieve efficient construction work

  • Compared to previous structure configuration, this track structure can reduce construction work costs on concrete track beds by 60%.
  • By optimizing the configuration of the structure, construction work is 1.7 times faster.

14. Profiling (through grinding) of aging rails based on X-ray diffraction analyses

  • Using X-ray diffraction analyses, it was confirmed that the influence of rolling contact fatigue on a rail had reached a depth of approximately 1.1mm.
  • Before grinding ageing rails to 0.1mm after every 50 million tonnes in passing traffic, a proposal was made to first grind rails to a depth of 0.3mm, and grind them again to a depth of 0.3mm after the next 50 million tonnes in passing traffic.

15. Improving OCL connector fatigue resistance

  • An OCL connector diagnosis diagram representing fatigue resistance and a set of anti-fatigue design guidelines were proposed.
  • A prototype connector was built with a fatigue life in excess of 10 million applications of stress from resonance and relative displacement between contact wires and messenger wires.

16. Proposal for light weight high-rigidity car body structure

  • An algorithm has been developed to derive body structures through analysis that are both highly rigid and light weight.
  • A proposal was made for press-molded body structures that have a 17% smaller mass and 12% greater bending rigidity than existing car body structures.

17. Reduction in manufacturing cost of C/C composite pantograph contact strips and clarification of their wear limit

  • 20% reduction in manufacturing cost of C/C composite contact strip through halving of carbon fiber content and modifying manufacturing process.
  • Clarification of the wear limit for the C/C composite contact strips considering the bolt-fastening force and strength of worn contact strips.
  • 50% reduction in usage cost of the C/C composite contact strip through the above two developments.

18. Method for evaluating serviceable life and deterioration of electronic interlocking equipment

  • A method has been developed to determine the serviceable life of electronic interlocking equipment based on their working environment.
  • A case study was used to determine the most critical electrical components in the device, and then age-related changes most likely to pose a risk of damage were identified.

Ⅲ.Harmonization with the Environment

19. Harmonics analysis modelling and harmonics suppression method for AC feeding systems

  • While taking into account the effect of resonance on PWM controlled vehicles, a method was devised to calculate harmonic resonance frequencies and conditions producing resonance.
  • The correlation between effective suppression and location of the harmonics resonance suppressor was also clarified.

20. Development of method for measuring and evaluating low-frequency aerodynamic noise and clarification of noise sources

  • A method has been developed to measure and evaluate the low frequency aerodynamic noise generated when a train runs at high speed.
  • The source of the low frequency aerodynamic noise was identified as being from the lower part of the vehicle housing the bogie.
  • The method could be used to verify the effect of noise mitigating measures through running tests.

Ⅳ.Improvement of Convenience

21. Passenger crowd density and walking speed in stations

  • A method was developed to measure, in detail, passenger crowd density and walking speeds in stations.
  • It was discovered that actual passenger walking speeds in a station were slower than the pace found with previous estimation methods.
  • Based on walking speed data collected in a variety of different conditions, the newly devised estimation method can be used for current station design.

22. Wheel slip suppressing control method using difference in current from the traction motors

  • A method for early detection and control of wheel slipping has been developed, based on the detection of difference in current from the traction motors.
  • The results of water sprinkling tests confirmed that the average rotational speed could be increased by over 5%.
  • The developed re-adhesion control method was adapted for use on commuter trains.

23. Method for predicting train delay and train occupancy rate with a lead time of several tens of minutes

  • A prediction method for train delay and occupancy rate with a lead time to several tens of minutes has been developed based on neural network.
  • Results from verification tests on an actual commuter line demonstrated that train delay can be predicted generally to within 30 seconds.

Ⅴ.Basic Research

24. Seismic resistance design method considering unsaturated condition of embankments

  • Following severe rainfall, water and air can be found mixed in the interstices of an embankment. Strength tests have shown that the strength of material in an embankment is greater when partially saturated than when fully saturated.
  • A method for designing the antiseismic reinforcement of embankments was therefore proposed, considering the unsaturated condition of an embankment.
  • A manual was produced and the design was applied in trials, which demonstrated that antiseismic reinforcement work costs could be reduced by up to 20%.

25.Method for estimating bridge maintenance indicators by combining measured and analytical values

  • A method has been developed to achieve highly accurate estimations of the maximum displacement and natural frequency of a bridge which are required for maintenance, through iterative correction calculation of input values based on measured and analytical values.
  • The maximum displacement and natural frequency can be estimated in approximately 5 minutes, which means that health condition of the bridge can be evaluated on site.

26.Quantitative evaluation of the impact force on a bogie due to a wheel flat

  • Vertical acceleration of the axle box caused by wheel flats is little affected by the wheel radius, but increases with the length of the wheel flat.
  • By evaluating the drop in the axlebox and its vertical acceleration, it was found that the place of impact between the flat on the wheel tread and the rolling rig varied according to speed in the circumferential direction.

27.Simulation of hot gas in tunnel fires

  • This simulation method can predict the thickness of hot gas layers to within a 10% error margin and temperature rise to within a 20% error margin.
  • This method can be used to assess evacuation guidelines and contribute to the design of underground ventilation installations.

28.Development of work-place decision-making tasks to assess decision-making skills

  • Based on information collected about decision-making errors through railway accident analysis, error prone situations can be detected. Following this, a set of decision-making tasks imitating these situations was developed.
  • When carrying out the tasks, the part of the subject’s brain related to decision making becomes activated, and confirmation can be obtained of the suitability of the task as an exercise.

29.Demonstration of vibration resistance and magnetomotive force of Yttrium-Barium-Copper-Oxide high temperature superconducting coil

  • A full-scale Yttrium-Barium-Copper-Oxide superconducting coil was produced, and evidence was gathered to demonstrate that the generated magnetomotive force of 750kA at 32K.
  • It was also demonstrated that heat generated by the coil under maximum acceleration of 15G stayed at +12% compared to its non-accelerated state, confirming that there was no loss of rigidity or of current characteristics.

・Ⅰ.5, Ⅴ.29 received funding from the Ministry of Land, Infrastructure, Transport and Tourism.
・Ⅰ.3 received a grant from transportation technology development promotion system of Ministry of Land, Infrastructure, Transport and Tourism.
・Ⅰ.8 is collaborative research with Hokkaido Development Engineering Center.
・Ⅱ.13 is collaborative research with Yokohama National University.
・Ⅱ.17 is collaborative research with Fine Sinter Co., Ltd..
・Ⅴ.24 is collaborative research with Chuo Kaihatsu Corporation.