ANNUALREPORT2018-2019
For the year ended March 31, 2019

Railway Technical Research InstituteForeword
Norimichi KUMAGAI
President of the Railway Technical Research InstituteFiscal 2018 is the 4th year of RTRI’s five-year
master plan RESEARCH 2020. Assessing its
progress accurately, we have been conducting
research and development and other tasks inorder to complete the master plan. Based upon
the needs of railway operators and the rapid
development of science and technologies, wehave been dynamically promoting research anddevelopment in order to create the technologies
that will lead the changing society and to provide
quality outcomes.
In 2018, Japan suffered from many disasters
by floods caused by torrential rainfalls, typhoons
and earthquakes in Osaka and Hokkaido. RTRI
provided railway operators with technical support
in investigating the causes of railway accidents,
disasters and equipment failures and in proposing
measures to prevent operation disruptions as wellas helped the investigations and restoration ofoperations in the disaster areas.
This fiscal year, we focused on the research
topics for enhancing railway safety. In Japan,
increasingly serious natural disasters such as
earthquakes, torrential rainfalls, strong wind andheavy snowfalls have frequently occurred in recent years. RTRI has been developing measures
to prevent derailment, level crossing accidents
and human errors and developing condition monitoring technologies as well as the technologies toenhance the resilience against the serious natural
disasters.

use information and communication technologies
including advanced sensing technologies, image
analysis using machine learning and high-speed
large-capacity communication systems.
We have been increasing the number of
researchers particularly in the fields of disasterprevention measures, energy saving and the
speed increase on Shinkansen. We have continued the construction of a new testing equipment
for dynamic and electrical tests of pantographand catenary for Shinkansen’s speed increase, a
new low-noise moving train model rig and a new
high-speed wheelset testing facility to enhancerunning safety. Furthermore, we have started toconstruct a new building to accommodate these
testing machines.
The ICT Innovation Project was also set up inorder to determine the direction of the research
into ICT and to establish an interdisciplinary research plan. Our supercomputer was replaced
by a machine with five times faster processing
speed.
We will continue to promote the research anddevelopment in order to enhance the value ofrailways and to be trusted by railway operatorsand other customers. Continued support andadvice from all the rail-related people will be mostappreciated.

We have also promoted research and development to build low-cost, energy efficient andconvenient railway systems, to raise Shinkansen’s
speed, and to further enhance simulation
technologies. In implementing these research
projects, RTRI has been seeking to extensively
Annual Report 2018-20191

Overview

Contents

Organization

2 Overview
Results of
4 MajorResearch and Development

34 News Release2

Board of Trustees

Board of Directors

Auditors

Annual Report 2018-2019

Railway Technical Research InstituteExecutive
Vice
Presidents

ChairmanPlanning Division

Compliance Division

Vehicle Structure
Technology Division
Vehicle Control
Technology Division
Structures
Technology Division

President
Executive
Directors

Administration Division
Miyazaki Test
CenterPower Supply
Technology Division
Track
Technology Division

Accounting Division
Disaster Prevention
Technology Division
Information
Management Division
Health Insurance
Systems Center

Signalling &Transport Information
Technology Division
Materials
Technology DivisionInternational Division
Research &Development
Promotion Division
Wind Tunnel
Technical Center
Marketing & Business
Development Division

Railway Dynamics
Division
Environmental
Engineering Division
Human Science
Division
Maglev Systems
Technology Division

Railway Technology
Promotion Center

Yamanashi
Maglev
Test Center

Railway International
Standards Center

Center for Railway
Earthquake Engineering
Research(As of April 1, 2019)

Annual Report 2018-20193

Major Results of
Research and Development
IMPROVEMENT OF SAFETY
1. Real-time hazard mapping system for localized heavy
rainfall-induced disasters• This system analyzes natural hazards caused by localized heavy rainfall in real time, and calculates
train stopping positions and evacuation routes for passengers to avoid hazard areas.
• This system can be used to support decisions on how to apply operational regulations currently inforce in case of rainfall.
Countermeasures to natural disasters causedby heavy localized rain, depend on being able toforecast these hazards, and being able to adapt
esponses over time. Being able to do this can help reduce
damage and accelerate resumption of services following disruptions. The system presented uses constantly
updated precipitation forecasts analyzed in real time basedon third party data and identifies inundation of small to
medium sized watersheds and large-scale landslides ata certain distance from railway, and then depending on
the outcome of these analyses shows suitable stopping
locations for trains or passenger evacuation routes.
The developed system includes 4 sub-systems (Fig.
1): ①A system for converting random-points precipitation
into graphs based on two-hour precipitation forecast data
received approximately every ten minutes from externalsources; ② A system which conducts sequential analysis
Drainage base + ○km
Rainfall zone
(prediction)○Preprocessing ofRainfall zone
(after correction) Drainage base potential heavy rainfall①Precipitation forecast
data display
Precipitation
forecast data(external source)from radar etc.
for target zoneof inundation hazards; ③ A system for displaying hazards
when forecast precipitation reaches a given threshold inareas that have previously been identified as possible locations of large-scale landslides; ④ A system for displaying
locations for trains to stop to avoid the hazard, and possible
routes for passengers to take in the event of an evacuation.
This system can identify where natural disasters, inundations and large-scale landslides are likely to occur
almost in real time, which can support operational decisions and determine evacuation routes and safe locations
for passengers to flee to in the case of heavy localized
rainfall, improving safety.
In addition, the system can prove useful for prior examination of equipment inspection periods and locations,to enable faster resumption of operations.

River

Portable data display
terminal (on site)zones around small
watersheds②Inundation hazards (water depth)
Water depth

Web

Railway operators

tool to determine train stopping③Large-scale landslide hazard ④Support
locations / passenger evacuation routes

Data display PC(office based)（Time-of-arrival and affected area）

Fig. 1 Railway disaster mitigation system against heavy localized rainfall, etc., based on forecast precipitation data

4

Annual Report 2018-2019

Railway Technical Research Institute

2. Earthing system testing device for lightning protection in power
supply installations• A new portable testing device has been developed to inspect earthing systems in fixed power supply
installations.
• The newly developed testing device makes it possible to perform a lightning protection testing with afaster current rise than conventional testing devices.
• The automatic data processing function in the developed device allows operators without special skills
to carry out tests.
Lightning protection tests (high frequency) of earthing
systems in fixed power supply installations cannot be
carried out using ordinary earthing resistance tests (lowfrequency) because of the difference in frequency components of the testing currents. The current waveform ofa lighting strike typically surges rapidly as shown in Fig.
1. Since lightning is a natural phenomenon, the surge
time is random. However conventional test results using
simulated lightning currents surging in few microseconds
were insufficient for the protection of ICT control equipment
in fixed power supply installations, because ICT equipment
is more vulnerable to lighting strikes than earlier relaybased control equipment.
Consequently, a new portable testing device for earthing
system inspection was developed as shown in Fig. 2. A
new developed power source circuit optimized for earthing
system testing was installed into the device. Comparedto the conventional equipment the circuit can generate asimulated lightning current with a faster surge in about
0.2 μs (blue curve in Fig. 1). The new testing device
can be used to evaluated lighting protection covering the95th percentile of lightning strikes, according to reported
statistics 1).

Furthermore, an automatic data processing function
including an algorithm to calculate the evaluation value(earthing impedance) was developed and installed into the
new testing device. The function allows operators, suchas railway maintenance workers, to carry out tests without
the need for special skills.
Table 1 shows the test results from two substation earthing systems on a railway line in operation. According to theresults, compared to conventional devices, the developed
device can evaluate conditions that are 3 to 10 times morecritical. The developed device can therefore be used forregular inspections, for detecting potential weaknesses ininstallations, and verifying the effect of earthing systemdesigns in order to improve protection against lightning, etc.
Table 1 Example of results from an evaluation of an installation in operation
Conditions

Dry

4.7Ω

42Ω

Substation B

Damp

9.6Ω

37Ω

〔Reference〕

1) Lightning Protection for Electrical and Electronic
Equipment, Institute of Electrical Installation
Engineers of Japan, OHMSHA，2011

Power source (simulated
lightning current generator)

Current

Approx. 0.7m

TimeEnlarged image of current surge zone
Current ratio

Surge time 0.2μs generated
by developed device

1
0.5
0

5

10

Time (μs)

1520Fig. 1 Testing device current waveform

Annual Report 2018-2019

Measuring device(waveform processing)

Approx. 1mSurge time in microseconds
generated by conventional device

0

Evaluation value
Conventional Developed
devicedeviceSubstation A

Several tens of microseconds
to several milliseconds
Typical lightning
current waveform

1.5

Soil

Fig. 2 Developed earthing system testing device

5

Major Results of Research and Development

3. Vertical damper to suppress decrease in wheel load on container wagon bogies• In order to suppress the decrease in wheel load on container wagons, improvements were made toa vertical bogie damper.
• Stationary vibration tests on a rolling stock test rig were performed on a single container wagon,
simulating actual cross-level track irregularity, confirming that the improved damper was able tosuppress wheel-unloading by approximately 20%.
In order to confirm the effect of the improved dampers,
stationary vibration tests were performed on a container
wagon on a rolling stock test plant (Fig. 2). Cross-levelirregularity track measurement data was input to the roller
rig, to reproduce in a test, the conditions that led to thepast derailment. As a result, when the speed of roller rig
was 60 km/h, it was found that the improved damper had
lowered the wheel-load reduction ratio on the third axle byapproximately 20% (Fig. 3).
Following main line running tests to confirm the validity of the new design with different loading conditions, a
proposal will be made to introduce the improved damper
into service as a way to improve the operating safety offreight wagons.
30
Attenuation force (kN)

When a carbody rolls due to track irregularity, there
is a decrease in wheel load. This can become a factor
leading to derailment in the case of container wagons.
Consequently, the vertical damper on the bogie was
improved.
On container wagon bogies, vertical dampers aremounted in parallel with secondary suspension to manage the switch in attenuation characteristics between theloaded and empty state of the wagon.
However, depending on the load conditions, etc., even if
the mass including the load corresponds to empty vehicle
damper characteristics, there are cases where rolling caneasily occur.
In such cases, if the vibration frequency caused bycontinuous irregularity at a constant wavelength and thenatural frequency of the vehicle rolling coincide, resonancecan occur, and the more rigid the secondary suspension,
the greater the relative attenuation force insufficiency ofthe damper, causing a cyclical decrease in wheel load.
Investigations were carried out using dynamic vehicle
simulation, to examine the attenuation characteristics ofcompliant dampers under different loading conditions,from empty to maximum loaded state. As a result, an
improved damper was proposed for vehicles with relatively
rigid springs, excluding empty state attenuation properties,
corresponding to unified loaded state characteristics whichstrengthened the attenuation force in the operating speed
region below 10cm/s (Fig. 1).

Improved

20 (characteristics
common to loadand empty state)0

Existing
characteristics(empty state)

0

5

15

20

Fig. 1 Attenuation force characteristics of the verticaldamperMaximum wheel loaddecrease ratio (%)

610Operating speed of damper (cm/s)

Approx.
20% reduction

60
40
20
0

Fig. 2 Vibration tests on rolling stock test plant

Existing
characteristics(load state)

1080

Vertical dampersristicracte gf cha xistin
Relieame as es

Existing Improved
damper damper

45km/h
50km/h
60km/hRoller rig rotation speed

Fig.3 Effect of suppressing decrease in wheel load using
the improved damper

Annual Report 2018-2019

Railway Technical Research Institute

4. Seismic reinforcement methods for improving anti-catastrophe performance of railway viaducts• A work method has been proposed to improve anti-catastrophe performance of railway viaducts
against unexpectedly extreme earthquakes.
• A dead-weight compensation structure was developed to prevent the collapse of viaducts.
• A structure to control the direction of collapse and failure behaviour of a viaduct, is developed to help
rapid repair.
Railway structures are built according to seismic design
requirements to guarantee safety and durability. However,
it is impossible to say that in future they will not be subject
to unexpectedly powerful earthquakes. Consequently, a
dead-weight compensation structure and collapsing-direction control structure were developed in order to increase
the seismic resistance of new and existing viaducts.
The dead-weight compensation structure ensures thateven if a viaduct’s piers are temporarily destroyed, a backup set of piers (dead-weight compensation columns) comeinto play to support the vertical load of the viaduct slabs,
thereby preventing total collapse (Fig. 1).
The tops of the dead weight compensation columns
are equipped with a Teflon slipping surface, severing theconnection with the viaduct and horizontal movement.
Consequently, the structure protects the piers from damage due to inertial force, and they are able to support thevertical load of the slabs. The results of loading tests

Dead weight compensation column
The slabs are supported and preventing viaduct collapse

confirmed that the structure with dead-weight compensation columns prevented the collapse of the viaduct evenwhen its piers were severely damaged by the shaking(Fig. 2).
Were the viaduct to collapse, the collapse-direction
control structure artificially controls the fall direction,
thereby protecting adjacent residential areas and emergency access roads, etc. (Fig. 3). As shown in Fig. 3,
a block-shaped device has been introduced to preventthe structure from collapsing in the undesirable direction.
Results from shaking table tests confirmed that the direction of fall (to the right) could be controlled when subjected
to vibrations equivalent to over twice the current level
required in seismic design (Fig. 4).
In addition to these large-scale tests, design methods
for applying the proposed methods to real structures
were proposed, based on a response analysis methods,
resilience evaluation method, and design method, etc.
Slabs supported by dead-weightcompensation columns,
preventing total collapse

Slab

Steel
plate

Slab

Teflonslip-surface
structure

Dead-weightcompensation column

The normal
columns aredestroyed

Severely
damaged columns

Fig. 1 Dead-weight compensation structure
Restraint

Free

Block
Pier

Restrained to
avoid collapse
in this direction

The viaduct is controlled tomake it collapse to the right

Viaduct collapses to the left

With the retraining blocks

Without restraining blocks

Viaduct

Residential areas andemergency access roads
Fig. 3 Schematic outline of the collapse-direction control
structure

Annual Report 2018-2019

Fig. 2 Effect of dead weight compensation structure in shaking table tests

Fig. 4 Effect of collapse-direction control structure in shaking
table tests

7

Major Results of Research and Development

5. Support System for verifying evacuation safety in case ofstation fire
• A system for verifying evacuation safety was developed to make it possible to keep a real-time visualtrack of the state of smoke propagation and passenger evacuation, in case of a station fire.
• The system makes it possible to verify evacuation safety based on distribution of the estimated numberof people being evacuated, based on station characteristics.
• It also makes it possible to verify evacuation safety considering the effect of evacuation instructions
broadcast over PA (public address) systems.
Design specifications in building standards are determined on the basis of maximum distances to emergency
exits, etc., which can be used to evaluate the safety ofevacuation in case of a fire in a station. However, theobjects of these specifications are often offices and othersuch spaces in stations. Generally, they do not consider
stations as a whole. Consequently, a support system wasdeveloped as a tool to verify the safety of station evacuation

measures when being designed, by predicting passenger
flows (evacuation times) and movement of smoke (timefor smoke layer to descend) (Fig 1).
A new calculation formula was created for estimating thenumber of people that need to be evacuated from the station concourse, which is needed for calculating evacuation
time. The estimation formula was created using passenger
flow surveys that were carried out in 5 stations of different size and layout. Using the input variables ofUsing the estimation formula to calculateconcourse surface area, number of station users,
Ticket barrier 2
the number of people that need to benumber of lines of movement, etc., the formula gives
evacuated from the station, their uneven
distribution at the beginning of thethe density of people that need to be evacuated per
evacuation is reproduced
section of station concourse.
As a result, using this formula dispenses with theneed to conduct on-site surveys to obtain a setting
for the number of people that need to be evacuated,
and it is possible to reproduce their distribution in
Ticket barrier 1
the station when a fire breaks out (Fig. 1).
In addition, employing the existing PA system inthe station used for assisting evacuation, tests wereconducted to examine the effectiveness of different
sound broadcasting methods to guide people out of
the station (Fig. 2). The effectiveness of instructions
given through the different broadcasts was inteMovement of people that need to be
grated into the system. Based on this integration,
evacuated from the station (towards
Room on firethe evacuation point) changes based(objects
it should be possible to investigate the effectivenessincludeall
officeson evacuation guidance announced
and concourses)
over the PA systemof different types of evacuation guidance to shorten
overall evacuation time (Fig. 3).
Fig. 1 Example of system output (initial distribution of people thatneed to be evacuated from the station)

Investigation into effect of sound level andcontent of two evacuation guidance broadcasts

600

Example broadcast B

400

Fig. 2 Evacuation guidance experiment conducted withhealthy subject

8

Smoke layer descent time from shop fire

300
200
100

Crowd noise 70dB Computer graphic (CG) projection of
space in station concourse projectedin headset worn by subject

Evacuation time through ticket barrier 1
Evacuation time through ticket barrier 2

500
Time (seconds)

Example broadcast A“Please evacuate through“Please evacuate throughticket barrier 1”(65dB～80dB) ticket barrier 2”(65dB～80dB)

0

Smoothing
Shortest
evacuation route

Evacuation instructions
broadcast over PA system

Fig. 3 Effect of evacuation instructions

Annual Report 2018-2019

Railway Technical Research Institute

6. Early railway line tsunami inundation forecasting method• A method was developed to give early estimations of inundated areas and water depth along railway
lines due to tsunamis, using tsunami data from the open sea transmitted from public institutions.
• Using data from the 2011 off the Pacific coast of Tohoku Earthquake, it was confirmed that it waspossible to obtain early estimations of inundated areas with an accuracy of over 90% approximately
one hour before the time the tsunami would have made landfall.
In order to accurately estimate the water depth ofinundations caused by a tsunami immediately after anearthquake, it would be effective to develop a method thatuses tsunami data from the open sea transmitted frompublic institutions. Consequently, tsunami data from the
National Research Institute for Earth Science and Disaster
Resilience and the results of a previously conducted tsunami simulation were used to develop an early tsunami
inundation forecasting method.

0

2.5

5

7.5 10km

Water depth ofinundation(m)
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0

(b) Japanese Cabinet Office Model
Fig. 2 Forecast accuracy of new method

Annual Report 2018-2019

Water depth of inundation (m)In step 1 of this method (Fig. 1), using tsunami data observed at one station out at sea and a previously preparedtsunami propagation function obtained through numericalsimulation of a tsunami, an estimation is made of the
expected tsunami height at the coastline. In step 2, using
inundation maps for various earthquake scenarios collected in a database, the inland inundation area matching
the estimated coastline tsunami height is extracted. Thismethod therefore has the unique feature of being able toimprove not only the timeliness of warnings
using data from a single observation station,
Forecasted tsunami
M8
M8height at coastline
but can also increase the impact on stability
Earthquake scenario
M8of the warnings by building databases ofObserved tsunami height
Selectedearthquake scenario
in the open sea
tsunami propagation functions and inundaApplication of matching
Forecasted inlandtion maps ahead of time.
methodtoforecast
tsunamiinundation areaheight at coastline
Applying this method to data fromOpen sea
Coastline
Step 2 :Step 1:
Forecastofinlandinundation
Forecastoftsunamithe2011 off the Pacific coast of Tohoku
line
area caused by the tsunami
height at coastline
way
Rail
Earthquake, and comparing the subsequent
Map corresponding to tsunami
Tsunami propagation function Earthquake
Inlandsource fault
inundation areas with those from the model
inundation based on the earthquake based on seafloor topography
scenario is prepared in advanceis prepared in advanceissued by the Japanese Cabinet Office as
Fig.1 Inland early tsunami inundation forecasting method
an accurate reference, it was confirmed thatboth areas matched by over 90% (Fig. 2). By the samemeasure, it was also confirmed that the water depth ofA
inundations caused by the tsunami could be estimatedA’approximately one hour before reaching the railway tracks.
Applying this method immediately after receiving tsunami data observed in the open sea, and by displaying thewater depth of inundations caused by the tsunami around
Over 90% matchthe tracks, it would be possible to communicate to trains
ahead of the flooding, which sections of track they could(a) New method
move to in order to remain safe for evacuation (Fig.3).
25
20
Sections of track
safe for evacuation

15
10

Sections of track
Sections of track
safe for evacuation safe for evacuation

5
0

25

A

20

15

10

Distance (km)

5

0

A’

Fig. 3 Real time extraction of sections of track safe for evacuation along railway line on route A-A’

9

Major Results of Research and Development

7. System for determining the stability of slopes during snowmelt season• A system has been developed to determine the stability of slopes during snowmelt season using
meteorological data.
• The system function without the need to install new observation equipment by using publicly available
information.
• The new method was able to detect 20% more cases of slope stability deterioration compared toexisting method.
A method has been developed to determine the stabilityof slopes during snowmelt season using the amount ofsnowmelt as an index.
In the existing method, the maximum amount ofsnowmelt in the area is used as a threshold for determining that slope stability has declined. However, in pastgeo-disasters, there have been cases where it was notpossible to determine whether slope stability had declined.
Therefore, a method has been proposed to determine
slope stability using two indicators: the snowmelt volume
and snow depth.
The new method uses observation data from AMeDAS
and public geographical data in the vicinity of the target
point to estimate the amount of snowmelt and snow depth
in order to determine slope stability. Using AMeDAS data,
past snowmelt volumes for each snow depth are thencalculated and then set as threshold values. By comparing the threshold values with actual snowmelt volumes

and snow depth calculated on the basis of AMeDAS data
updated on an hourly basis, it is possible to determine
the slope stability (Fig. 1). Taking past geo-disasters as areference, the ratios of successfully detected deteriorated
slopes (disaster detection rate) using the existing andnewly developed methods were compared. The resultsof the comparison confirmed that even though results inboth systems were the same in terms of the time in which
the amount of snowmelt exceeded the threshold value, thenewly developed method’s disaster detection rate was approximately 20% higher than the existing method (Fig. 2).
Given that the new method only uses publicly available
data and information, it allows the stability of any slope to
be examined, without the need to install a new network ofobservation equipment. In addition, the system is designed
so that if the system is used in an environment with internet
access, the user can obtain a visual display of the slope
stability result in any location, as shown in Fig. 1.

Target point

Target point 2

100

Target point 3

Lowstability

Threshold value 3※(return period t : 8 years)
Threshold value 2(return period t : 4 years)
Threshold value 1(return period t : 2 years)

Snowmelt volume RC (mm)Target point 1
80

Sequential determinationof slope stability

60
40

Cut off value

20

Actual snowmelt volume

Newly developed
methodExisting method
Threshold value 1(t=2 years)
Threshold value 2Threshold value 1(t=4 years)(RC=35mm)

90
80
70

Thresholdvalue 360 (t=8 years)

20% improvement

50
40

Threshold value 2(RC=70mm)

30

Threshold value 3(RC=maximum recorded value)

20
10

0

0.0

0.2

0.4
0.6
0.8
Snow depth (m)

1.0

1.2

※ The value for return period t : the value shows the numberof years on average for a given phenomenon to occur once

Fig. 1 Example of result of slope stability determination insnowmelt season (Target point 1)

10

100

Disaster detection rate (%)

Target point 1

0

0

100

200

300

400

500

Duration over one winter that a thresholdvalue is exceeded (time)

Fig. 2 Result of disaster detection rate comparison between
newly developed method and existing method

Annual Report 2018-2019

Railway Technical Research Institute

8. Measures for reducing damage to overhead contact line
system due to bridge oscillations caused by passing trains• A computation method was developed to analyse coupled oscillation between bridges and catenary
poles caused by passing trains, which also revealed the conditions under which overhead contact line
system oscillations were largest.
• As a means to prevent wire fatigue failures in overhead contact line systems due to large bridge
oscillations caused by passing trains, a new metal fitting was designed and a decision-making flow
chart was proposed to determine whether measures had to be taken or not.
On some sections of simple-support bridges, wire
fatigue failures in overhead contact line systems have occurred due to large bridge oscillations caused by passing
trains. The amplitude of bridge and catenary pole oscillation depends on their type and design. Consequently, it isnecessary to clarify what conditions of bridge and catenary
pole lead to wire fatigue failure, and to identify the criteriathat determine whether measures have to be taken or not.
A computation method of coupled oscillation between
bridges and catenary poles (Fig. 1) was developed to beable to calculate their complex coupled oscillation. It was
found that calculated response displacements coincidedwith measured values. This new computation method istherefore able to reveal the conditions that cause larger

Catenary pole (beam element)xyCriteria of fatigue
breakdownTrain running line

Stiff beam

Horizontal (to bridge)

Bridge (beam element)
Axial direction(in relation to bridge)

Fig. 1 Coupled oscillation model of catenary pole and bridge.

Catenary poleoscillation location

Measured value (new system)
Calculated value (new system)
Measured value (existing system)
Calculated value (existing system)

Newly added
metal connector

2000
1000
0

0

50

100

150

Total amplitude of catenary
pole displacement [mm](Results of excitation tests) (Newly developed system)
Fig. 2 Structure of wire support metal fitting to reduce strain
on wire※Criteria of metal fitting wear management

Oscillatory measurement
Total amplitude＞20mm※

Strain on wire ×10-6

Perpendicular
directionz

oscillations in overhead contact line systems. These results can be used to screen which existing bridges haveconditions that are likely to cause wire fatigue failure, andto select which measures should be applied to prevent
damage.
The total amplitude of catenary-pole displacement thatcauses wire fatigue failures was then clarified. Whenthe total amplitude exceeds 50 mm, insulator rotation isrestricted, resulting in a tremendous strain on the wire.
Consequently, a new metal fitting was developed to reduce
this strain (Fig. 2). In addition, a decision-making flow
chart was proposed to determine whether measures had
to be taken or not (Fig. 3).

No

Yes
Measures are needed(Total amplitude over 100mm)

Catenary pole measures +metal fitting measures +wear management(Total amplitude 50〜100 mm)

Catenary pole measures ormetal fitting measures +wear management(Total amplitude 20〜50 mm)

Catenary pole measures orwear management

No measuresneededFig. 3 Decision making flowchart about catenary pole oscillation whether measures need to be taken or not

Annual Report 2018-2019

11

Major Results of Research and Development

9. VR-based training to prevent man-vehicle collision accidents• A training method using virtual reality (VR) technology, was developed to teach railway personnel about
the processes leading to man-vehicle collision accidents and the risks of working alongside tracks.
• Tests using the training method with on-site railway personnel led to a 21-point increase in the numberof staff who followed rules completely.
There is a need to educate frontline railway personnel about the risks of violating rules, however, there has
been a lack of clarity about exactly what risks should behighlighted during training.
After analyzing past cases involving track maintenanceor work on electrical installations, and conducting opinion
surveys among on-site railway personnel, it became clearthat training was necessary in particular to understand the“processes leading up to accidents” in order to promote
more rigorous rule keeping.
Consequently, a “VR experience-based training method”
was developed to provide training on better understanding
the processes leading to man-vehicle collision accidents(Fig. 1). The training method comprises two types of module, the “Virtual reality experience” and “Case transfer.”
The “VR experience” module is a role play exercise where
the subject is given the role of the person in charge of aworksite. The subject is immersed in a VR scenario, where
they can walk around a simulated space and participate in
Explanation of purpose
VR experience

Image of subjects
during training

VR scene seen
by participant

track maintenance work. One of the scenarios used raises
awareness about the process that leads to a man-vehicle
collision accident due to lack of attention to approaching
trains when fully absorbed in a task: through the exercise,the subject is able to understand the importance of moving
away from a track at the right time (Fig.2). The “Casetransfer” part of the training, uses past cases as a reference. Subjects take part in a group discussion, and reflect
on how the process leading to a man-vehicle collision accident could apply to their own workplace, and examine
what tangible countermeasures could be implemented.
The “VR training method to prevent man-vehicle collision
accidents” was trialed with a group of on-site personnel.
The training improved their understanding about how
man-vehicle collisions occur, and compared to before thetraining, the number of respondents who said they would
fully comply with rules for moving away from tracks at theright time, rose by 21 points (Fig. 3).
The satisfaction level among participants was particularly high for the VR experience, with 96% of respondents
agreeing that it was “true to reality.”
It is hoped that implementing this training will increaselevel of compliance with rules that can prevent man-vehicle
collision accidents.

Case transfer exercise
Explanation by
instructor
Fig. 1 Outline of “VR-based training method to prevent
man-vehicle collision accidents”
0

Maintenance workon tracksMoving awayfrom tracks
at the right timeWorker is fully absorbed
in task (human error)

Beforetraining

Non compliance with rules
Work continues

Process leading
up to man-vehicle
collision accident

Man-vehicle
collision accident

Fig. 2 Example of VR scenario

12

One monthafter training

percentage (％)
50

Definitely comply

100

Sometimes don’t comply

21-point increase
Definitely comply

Sometimes
don’t comply

・Answers from a) - d) on behavior collected one week after training
Regarding the rule which requires workers to move away from track
within a given time before a train passes「a) I always comply」「b) I do not always comply 」「c) I don’t often comply」「d) Not applicable I do not do this type of work」
・Analyzed except d) (43 respondents) ,c) No respondentFig.3 Rule compliance behavior before and after training

Annual Report 2018-2019

Railway Technical Research Institute

10. Method for evaluating train running safety during earthquakes considering non-linear behaviour of structures• A method has been developed for evaluating the running safety of trains during earthquakes taking
into account the non-linear behavior of structures.
• Using design drawings and specifications, the method is able to rapidly detect existing elevated bridges
that present a weakness in terms of running safety during earthquakes, which can help selection ofsuitable countermeasures and prioritization of work.
As work progresses to implement measures against
derailment or install derailment prevention guiding devices,
there is a growing need to find a way to rapidly and accurately detect vulnerable sections of line on the networkin terms of Shinkansen running safety during earthquakes.
The response of structures built according to old design
standards, in some cases under L1 seismic motion fell into
a non-linear domain, that was outside the scope of methods cited in existing design standards. This created the
problem that detailed numerical analyses then needed tobe performed which were both costly and time consuming.
Dynamic interaction analyses between vehicles andstructures were therefore carried out, and a comprehensive
investigation was made into the influence of various factors
such as vehicle type, running speed, vibration characteristics of structures and type of earthquake, on derailment

Train running safety during an earthquake

Limit in design standards (former)

Vibration displacement

Differential displacement

Angular rotation of structural
boundary

Derailment

×

Vibration displacement

Acceleration of the topof the viaductlimits considering the non-linear behavior caused by theyielding of the structure. An evaluation method was thendeveloped taking into account the coupled influence ofstructural vibration displacement (acceleration) and structural boundary differential displacement (angular rotation)(Fig. 1). The applicability of the new evaluation method
was verified by comparing its output with results from thedetailed numerical analysis.
The present method extends the scope of evaluation
to non-linear domains that were beyond the area of application of the design standards. In addition, by using
structural design drawings and specifications, it is possible
to rapidly and accurately extract vulnerable sections, tosupport the selection of countermeasures and prioritizationof work (Fig. 2).

Proposed derailment limit curve

Response value

Response value
No derailment
Derailment

Safe
Extension

Limit value

Limit value

Differential displacement
Fig. 1 Running safety evaluation method considering non-linear structural behavior

Overroad bridge

Contribution of differential displacement ofstructural boundary
Contribution of vibration displacement due
to structural acceleration

Overroad bridge

RSI = 0.6

0.8

1.2

0.6

0.8

0.8

0.8 0.8

Vulnerable point

0.6

1.2

0.8 0.6

Vulnerable point

Effect■Determine whether there is a derailment or not■Extraction of vulnerable points, setting orderof priority■Selection of countermeasure work based on
RSI (Relative Strength Index) value

Fig. 2 Main effects and image of application of proposed method

Annual Report 2018-201913

Major Results of Research and Development

11. Critical wind speed of overturning based on actual measured lateral vibration acceleration• A method for calculating the critical wind speed of overturning with the use of measured lateral car-bodyvibrational acceleration values has been proposed, making it possible to evaluate the resistance tooverturning in accordance with a train’s actual running conditions.
• A stochastic interpretation of the critical wind speed of overturning following analysis of the frequency ofoccurrence of lateral car-body vibrations, will make it possible to add a safety margin to the evaluationof crosswind stability against overturning that reflects the assumed probability of occurrence.

1

linear equation including the vibrational acceleration peakvalue of waveforms measured at different speeds (Fig.
1), resulting in some cases where the critical wind speedof overturning was calculated to be as high as 2-3 m/s(Fig. 2).
This method also allows stochastic interpretation of thecritical wind speed of overturning following analysis of thefrequency of occurrence of lateral car-body vibration (Fig.
3). Adopting a new annotation of results of the calculationof the critical wind speed of overturning which separates
the average (deterministic) and fluctuating (stochastic)
parts, it is possible to calculate the critical wind speed ofoverturning with quantitatively incorporated safety margins
that reflect the assumed probability of occurrence. In turn,this makes it possible to take into account the balance
required between safety and operational stability whensetting wind speeds for operation control.

Actual measured values
Current assumption
Assumption based on
actual measured values

0.8
0.6

0.2

0.4
0.2
0

0

20

40

60

※Example of results from
actual measured values

80

100

120

Running speed (km/h)
Fig. 1 Relationship between running speed and lateral
vibrational acceleration

Probability density

Lateral vibrational
acceleration (m/s2)

The crosswind stability of railway vehicles against overturning can be evaluated from the critical wind speed ofoverturning. Using the detailed RTRI equation for calculating the critical wind speed of overturning, which takes into
account not just vehicle and infrastructure specifications,but also many other factors, and based on a premise of
the severest running conditions, including wind direction,
lateral car-body vibration due to constantly changing
track irregularity, it is possible to make safer evaluations.
However, for train operators to use this method on a daily
basis for train operations, it would be more practical if theevaluation reflected more real track and other tracksidewind conditions.
Consequently, this research makes a proposal to apply
actual measured lateral car-body vibrational values to thevibrational inertia term in the RTRI detailed equation. In
this method, the existing assumption of the linear equation(in the RTRI detailed equation), is replaced with an adapted

2.5m/s0.15

Assumption based on
actual measured values
Probability of occurrence
corresponding to SD of 7
0.1
Current
assumption
Corresponding to
0.05 SD of 1-4

Average critical windspeed of overturning

Critical wind speed ofoverturning (m/s)※ Standard

0

40
35
30

Current assumption
Assumption based on
actual measured values

25
20

0

20

40

60

100

24

26
28
30
32
34
36
Critical wind speed of overturning (m/s)

Example of annotation of critical wind speed of overturningwith probability of occurrence corresponding to SD of 7

※Speed exceeding
2-3 m/s based on
conditions in Fig. 1

80

Deviation (SD)

Critical wind speed of overturning : 30.3 ± 2.5m/s
120

Average part

Fluctuating part

Running speed (km/h)

Fig. 2 Example of calculation of critical wind speed ofoverturning

14

Fig. 3 Example of stochastic interpretation of critical windspeed of overturning (illustrating new annotation method)

Annual Report 2018-2019

COST REDUCTION

Railway Technical Research Institute

12. Method for monitoring state of driving devices using vibration analysis and machine learning• A method was developed where vibrations are monitored constantly, allowing the system to detect
abnormalities through comparison with normal vibrations.
• The method does not require detailed information about the design of equipment or any abnormal
vibration data related to failures.
• This method also allows the classification of abnormalities and evaluation of the degree of abnormality
based on the abnormal vibration rate per frequency band.

Communication bymobile phone, etc.

Monitoring equipment
mounted on train

Vibration sensor
Driving gear

Train side
Track side

1 second
Vibration
wave form

Octave Band
analysisA

30%High frequency
Middle frequency
Low frequency

20%
10%
0%
70

Classification Oscillation
frequency

58

44

32

22

Type of abnormality
・Imbalance

Low Below
frequency 100Hz ・Misalignment

A：Nearest training
data to X

・LoosenessTraining data (normal condition)

 Per-second octave band analysis output⇒Analysis of main components⇒ coordinates plotted in multidimensional space Large distance between X-A ⇒ considered to be abnormality

Fig. 1 Conceptual outline of abnormality detection andstructure of condition monitoring system

Annual Report 2018-2019

40%

9Fig. 2 Abnormal vibration ratio at time of malfunction in auxiliary driving gear due to wear

X

PC

50%

Number of days until malfunction (days)

X：Test data
ServerIn doing so, any abnormal vibration would produce anisolated plot, making it possible to detect an abnormality
based on the distance from the points plotted for normal
vibrations.
Then, by separating octave-band analyses results byfrequency band and detecting abnormality separately, it ispossible to predict the type of abnormality that has been
detected (Table 1). Furthermore, by estimating the abnormal vibration rate within a given timeframe, it is possible
to evaluate the speed of progression of the abnormality.
Trials were conducted with the developed monitoring
system mounted on an actual train, which demonstrated
that indications of an abnormality were detected 50 days
before the auxiliary driving gear malfunctioned (Fig. 2).

Abnormal vibration ratio

Early detection of driving device abnormalities is required to guarantee the safety and stability of transport. A
method for monitoring the state of vehicle driving devices
was therefore developed.
An effective way to check the state of traction motors
and engines is to monitor vibrations. However, given thecomplex, changing operating environment of driving equipment, and vibrations generated by actual running of the
train, it is difficult to detect abnormalities based simply on
the amplitude of the vibration. As such, machine learning
was applied to the outcomes of vibrational octave-band
analyses, in order to develop a method for detecting abnormalities based on differences with normal vibrations(Fig. 1).
The principal components of vibrational data obtained
from octave band analyses were plotted as coordinates.

Remedy(example)

External visualinspection
Dimensional
measurement
Hammering test
Hammering test

Middle 100Hz ・Loosenessfrequency ～1kHz ・Wear or collision (Bearing etc.) Lubricant inspection
Overhaul inspection

High More than ・Wear or collision (Bearing etc.) Lubricant inspection
frequency 1kHz ・Flaw or cracking (Bearing etc.) Overhaul inspection

Table 1 Type and frequency of abnormal vibration15

Major Results of Research and Development

13. Wheel flange-wear reducing wheel-tread friction block• A wheel tread friction block was developed, which reduces wear and friction of the flange by using
solid lubricant.
• Tread abrasive material and solid lubricant were combined into a block, which is interchangeable withexisting abrasive blocks.
• Line tests with a pendulum express train confirmed that wheel wear could be reduced by approximately
40%.

Abrasive block
Wheel flange
Wheel tread

Abrasive block

Solidlubricant
固体潤滑材(composition : Molybdenum disulfide. graphite)
Wheel tread cleaning device

Wheel

Integrated wheel-tread
conditioning block

Fig .1 New integrated wheel-tread conditioning block
structure and appearance when mounted

16

Wheel flange wear rate (Trailer)(mm/104km)

Solid lubricant(Fig.1). The wheel-tread conditioning block is molded as asingle piece, and the block as a whole including boundaries
between the solid lubricant and the tread abrasive material
meet the same strength criteria as existing tread abrasive
blocks. Furthermore, the composition of the tread abrasive
material in the new block is the same as the tried-andtested material used in existing tread abrasive blocks.
The new blocks move vertically by the action of thewheel-tread cleaning device, and therefore no adjustment
is required for different wheel diameters. In addition, thewear rate of the integrated wheel-tread conditioning blockis identical to that of the tread abrasive blocks, so no additional serviceable life management is required.
Introducing the new integrated wheel-tread conditioning block on a pendulum express train, on which existinggreasing methods cannot be used, confirmed that wheelflange wear was approximately 40% lower than without
the integrated conditioning block. It was also confirmedthat the friction coefficient on the flange was lower (Fig 2).

Wheel flange friction coefficient(Tribometer reading value)

Wheel flange wear progresses through flange-rail contact as trains run through curves, and a rise in the numberof wheel re-profilings leads to increased costs, creating theneed to control wheel-flange wear.
However, for noise and the derailment safety margin,a low friction coefficient is desirable. To overcome thisproblem, flange lubricant is required. Greasing methods
do exist, however, they can lead to wheel slipping andtransfer of grease to the rail, and a work adjusting lubricant
position is required, making these methods sometimes
difficult to apply. A new wheel-tread friction block wastherefore developed (hereinafter, ‘integrated wheel-tread
conditioning block’), combining lubrication of the flange
and wheel tread adhesion improvement.
The new integrated wheel-tread conditioning block consists of wheel-tread abrasive material which is in contact
with the wheel-tread, a built-in solid lubricant component
in contact with the wheel flange, and can be installed inexisting wheel-tread cleaning devices without modification

0.4
0.3

16 new blocks fitted on 2 out of the 3 trailercars in the trainset
90,000km point after fitting the new blocks

Lower wear rate

0.2
0.1
0
0.7
0.6
0.5

Trainset with no new blocks Trainset with new blocks
90,000km point after fitting the new blocks

Friction coefficient falls

0.4
0.3
0.2
0.1
0

Trainset with no new blocks Trainset with new blocks

Fig. 2 Reduction of wheel-flange wear / friction

Annual Report 2018-2019

Railway Technical Research Institute

14. High-strength bolted friction joints for existing weathering
steel bridges• A high-strength bolted friction joint connection method with protective rust was developed for the repair
or reinforcement of weathering steel bridges.
• Design methods were also proposed corresponding to different rust conditions and different surface
properties of the reinforcement/repair members.
• The new method is only 1/3 of the cost of conventional methods.
Weathering steel bridges are a special type of bare-steel
bridge where corrosion is prevented by the protective rustthat forms on the steel surface (Fig.1). Bridges of this type
began being built 40 years ago and today the first signsof fatigue cracking and other damage are beginning toappear, calling for increasingly urgent repair and reinforcement. However, in order to apply repair or reinforcement
members, rust has to first be completely removed from thesteel surface with large-scale blasting equipment, which isextremely time consuming and expensive.
A method of high-strength bolted friction joints withprotective rust was developed for the repair/reinforcementof existing weathering steel bridges. In this method, only
the surface grained layer of protective rust is removed

with a hand-held electric brush (Fig. 2), and the friction
between the contact surface of the inner layer of protective
rust and repair/reinforcement member ensures the joint
strength (Fig.3). The slip coefficient used for the designof the friction joint strength is determined according to thesurface properties of the repair/reinforcement member
and the protective rust and depending on the bridge’s surrounding environment (Table 1). Furthermore, the surface
condition of the protective rust can be classified using
a visual inspection index (Table 1). Using the proposed
joint method, means that large scale blasting equipment
to remove rust in reinforcement/repair work is no longer
required, shortening work time and reducing work cost by
approximately 2/3.

Joint with high-strength bolt

Existing weathering
steel bridge(only surface grained
layer removed)

Protective rust

Repair / reinforcement
memberForce

The friction produces joint strength(calculated with slip coefficient)Fig.1 Weathering steel bridge

Fig. 3 High-strength bolted friction joints

Repair/reinforcement
member surface properties

proposed method
Removal of only surface grained

layer of protective rustHandy electric brush
Inner layer ofprotective rust

Steel

Removable with simple hand-held tool
regardless of the skills of the worker

Fig. 2 Removal layer and equipment

Annual Report 2018-2019

Condition ofprotective rust
Visual inspection index

Conventional

Complete removalof protective rust

Blasted steel Zinc coating

5 Good
0.5

4

0.3

3
2
1

Bad

0.4
※Complete rust removal anduse of adhesive

Table 1 Slip coefficient17

Major Results of Research and Development

15. Bridge pier stability monitoring method using microtremordata• A system was developed to monitor the natural frequency of bridge piers using microtremors measured
at the top of bridge piers.
• The system allows monitoring of bridge piers even in situations where the influence of ground vibrations
is significant.
• Using this method prior measurement of the natural frequency through impact and vibration tests is
not necessary.

Sensor 2

Estimation of ground vibration based on
Incremental difference in microtremor
waveforms and geometric relationshipbetween rotation center of pier vibrationand sensor position③
After removing the estimated groundvibration from the measured pier vibration,
the Fourier spectra ratio is calculated④
The calculated Fourier spectra ratio isconverted to curvilinear regression
using theoretical equation to identify
the natural frequency

Fourier amplitude(spectra)Sensor 1②

Fourier spectra ratio

Sensors are placedon the top of the pierFourier spectra ratio

Measurement of microtremors
upstream and downstream on
the top of the pierFourier amplitude(spectra)The stability of bridge piers can be assessed by using③ The estimated ground vibration is then subtracted fromthe natural frequency of the pier obtained through impact
the measured values; ④ The values are then converted
and vibration tests, however, these tests involve creating
to a curvilinear regression using a theoretical equation to
impacts using weights, which from a practical point ofidentify the natural frequency of the bridge pier.
view is not viable for periodic monitoring. As a solution to
The new method was used to identify the natural
this problem, a monitoring method was developed using
frequency of 12 bridge piers, which were comparedpier microtremor measurements. However, in the casewith the natural frequency obtained through separatelyof large ground vibrations, pier vibrations were drowned
conducted impact and vibration tests. The results of thisout by the ground vibrations, so the method could not becomparison demonstrated that apart from one pier thatapplied. Consequently, in contrast with the single measurewas in exceptionally good condition, it was possible toment location used in this method, another microtremor
identify the natural frequency of each of the 11 other piersmonitoring method was developed based on two (Fig. 1)even in conditions heavily influence by ground vibrations
microtremor measurement locations on the top on the pier,to within 1 Hz.
and then subtracting the estimated ground vibration, toGiven that this new method does not require priormake it possible to monitor the natural frequency of themeasurement of the natural frequency through impact andpier even in conditions where influence of ground vibrations
vibration tests, it is much more practical to implement. In
is significant.
addition, since microtremors values are used, it is possible
The new method (Fig. 2) works as follows: ①two microto monitor to the piers even with rising water levels.
tremor gauges are placed upstream and downstream on
the top of the pier, and two microtremors are measured; ②
Ground vibration is estimated using measured values;
Pier vibration Natural frequency①
obtained throughimpact andvibratio tests

Vibration frequency (Hz)÷
Estimated ground vibration

Vibration frequency (Hz)Vibration frequency (Hz)Vibration frequency (Hz)Curvilinear regression obtained
through theoretical equation

Fig.1 Schematic showing sensor location

18

Fig. 2 Process for identifying the natural frequency using the new method

Annual Report 2018-2019

Railway Technical Research Institute

16. Low-cost continuous welded rail track structure suitable forregional railways• A track structure has been developed that can be introduced at half the actual cost.
• Lateral ballast resistance force is maintained by mixing cement to reinforce existing ballast.
• Tests on a full scale model track confirmed that the track did not buckle with a rail temperature riseof 70 °C

Replacement with
PC sleepers incertain sections

Existing 40kgN rail
( joint depressions cut and welded)

Existing wooden
sleepers
Lateral ballast resistance force reinforcement measure(mixing of existing ballast with cement)
Fig.1 Low-cost continuous welded rail track structure

Annual Report 2018-2019

done, no buckling occurred when the temperature of the rail
was increased by 70 °C (Fig. 2). In addition, when using
RTRI’s test line installations, it was confirmed that lateralballast resistance force track reinforcement work could be
carried out for less than 20 000 JPY (approximately 165
Euro or 183 USD) per meter of track.
As a result, the new continuous welded rail track structure can be introduced for less than half the current cost.

Increase in temperature of rail (degrees)

Rail joints, which are a weakness in tracks on regional
railways are a significant problem in terms of maintenance,
given their high number, and so a low-cost effective means
to reinforce track structures is essential. It is thought thatone potential, effective method to solve this problem in particular, would be to develop a low-cost method to introduce
continuous welded rails, which would remove rail joints andsignificantly reduce maintenance costs. However, existing
continuous welded rail track structures are designed fortrunk lines, and would be difficult to introduce on regional
railways given the high implementation cost.
In the proposed track structure, some wooden sleepers
are replaced with PC sleepers, while the soil/ballast mix is
kept as it is, and joint depressions are sectioned off andwelded. In order to maintain the lateral stability obtained
through analysis the lateral ballast resistance force of
14.7kN required in certain sleepers is guaranteed by adding cement to the ballast through stabilizing reinforcement(Fig. 1).
The developed continuous welded rail track structure
was used to build a full size track model, and rail heating
tests were conducted. The results confirmed that after
the lateral ballast resistance force reinforcement work was

80
Without lateral ballast resistance force reinforcement
With lateral ballast resistance force reinforcement

7060

No buckling : 70℃

50Buckling at : 42℃

Buckling

X

40
30
20
10
0

State after buckling
0

50
100
150
200
Lateral rail displacement (mm)250

Fig. 2 Result of buckling stability verification experimentusing full scale track model

19

Major Results of Research and Development

17. Track stiffness inspection method using portable track stiffness measuring device (RFWD)• A method using a portable RFWD for rapidly inspecting track stiffness was designed.
• The method can be used for checking track stiffness after restoration work and for designing roadbed
improvement.
A method was proposed to inspect the state of sleeper
support and roadbed stiffness using a portable track stiffness measurement device (RFWD Railway Falling WeightDeflectometer) (Fig. 1 and Fig. 2). The portable RFWD
is a device drops a weight onto the rail and, based on
the load and the displacement, measures the track springcoefficient. It is therefore used to evaluate track stiffness
to assess the need for track repair work or track restoration
after work under the roadbed. Up until now, there wasno portable machine that could be used along the rails inorder to exert a load on the track to inspect track stiffness,
however, measuring can be done swiftly with the highly
mobile portable RFWD. Using the portable RFWD, measurements on one sleeper can be taken every 11 seconds.

Sleepers lacking the sufficient stiffness (floating sleepers) can be detected (Fig. 3), which makes it possible tocheck track safety after work has been carried out under
the roadbed, or after track restoration work following adisaster, before allowing traffic to resume.
In addition, the track spring coefficient obtained with theportable RFWD can be used to identify locations along theroadbed that require repair, and determine the thickness
that needs to be replaced as well.
Several railway operators have commenced pilot tests
using the portable RFWD.

Loading unit

The portable RFWD

WeightDrop
Signs of track
subsidence due tocavities under the roadbed

Load cell /displacement gauge

Work under the roadbed

Fig. 1 Portable Railway Falling Weight Deflectometer(RFWD)

6
4

Delay in displacement response measured
with portable RFWD
(Time difference between load and displacement peak)

2

-10
-5
0

0

-2
-4
-6
-8
5140

5

Static-dynamic difference(seriousness of floating
sleeper condition) in 5 m
chord versine

10
Floating sleeper

5150

5160

5170

5180

Position (km point)(m)

5190

15
5200

Delay in displacement response (ms)

Static-dynamic differencein 5 m chord versine (mm)8Fig. 2 Inspection of track stiffness using the portable RFWD

Fig. 3 Example of diagnosis of track stiffness using the portable RFWD

20

Annual Report 2018-2019

Railway Technical Research Institute

18. Device to determine fouling of structural clearance gauge
using on-board 3D laser scanner• A system has been developed to determine fouling of the structural clearance gauge by any of thenumerous facilities that exist beside tracks.
• The device can be mounted on a track geometry inspection car, and in some sections can reduce theneed for manual measurements by 90%.
• Confirmation was obtained that the error margin in the lateral direction was less than 200mm.
To guarantee the running safety of railway vehicles, it
is essential to determine whether any trackside structures
foul the clearance gauge. In the past this was achieved
manually or with a specially equipped car for inspecting
the structural clearance gauge, however, the problem withthis method, is that it is both time and labor intensive, andthe initial cost of building such special cars is expensive.
Consequently, using a “3D laser scanner” which measuresdistances to target objects based on beam reflection time,a clearance gauge fouling detection device was developed,
which can measure trackside installations continuously(Fig. 1). The device can be mounted on any kind ofvehicle, and can inspect structural clearance gauges at
up to 80km/h, making it possible to check the structuralclearance gauges at a lower cost.
In order to measure the clearance gauge, two pairs of
3D scanners are fitted to the top left and right gable ends ofthe front of a vehicle. Two more 3D scanners are mounted
on each side of the lower part of the front end of the vehicle
to measure the track position, to correct vehicle vibration

when running. The lateral error in distance measured forlarger trackside installations, such as level crossing gatesand equipment boxes was within 50 mm, while for thinner
items, such as signaling markers, the error margin waswithin 200mm, confirming that the system satisfied thetarget accuracy (within 200mm) (Fig. 2). Satisfying theaccuracy criterion of 200 mm, signifies that depending on
the conditions of the track section, the need for manual
measurement could be kept to below 10%.
Given that this device is fitted onto a track geometry
inspection car, the structural clearance can be measured
according to the schedule of usual track geometry inspections. Consequently, the clearance gauge can be checked
now without the need for a specially operated car. In addition, given that the data is collected in 3D configuration(Fig. 3), it is possible to identify which piece of an installation is fouling the gauge, and obtain the cross-sectional
shape of the track bed, to determine how good or bad asituation is.

900 mm Distancefrom clearance gauge

3D laser scanner for measuring
the clearance gauge
3D rail scanner for detecting rails
Targetinstallation

Fig. 1 Example of application of the device for determining
fouling of the clearance gauge

Forward image

1,000mmFig. 2 Measurement of distance from clearance gauge

Measurement data

Fig. 3 3D display of measurement data

Annual Report 2018-2019

21

Major Results of Research and Development

HARMONY WITH THE ENVIRONMENT
19. Method for evaluating characteristics of wheel/rail noise
generated in curved track sections• An on-site evaluation method has been developed to characterize high-frequency noise produced bywheel and rail vibrations above 10 kHz generated on a gently curved track.
• The dominant source of high-frequency noise was identified as being the outside leading wheel ofeach bogie.
• The method can be used to evaluate the characteristics of wheel/rail noise and serve as a guideline
for the development of mitigation measures.
It is common knowledge that squeal noise can occur
when a train runs through a sharp curve. However, even on
a gently curved section, wheel/rail noise due to wheel andrail vibrations above 10 kHz (referred to as “high-frequency
noise”) close to the upper limit of the audible frequency
range can occur and significantly contributes to waysidenoise (Fig. 1). In order to develop measures to reduce thisnoise, it is necessary to understand its characteristics, suchas the contribution to overall noise of each noise sourceand source localization.
As such, an evaluation method was designed (Fig. 2)

A-weighted soundpressure level (dB)Train passing

Measurement(frequency components
below 20 kHz band)

Contribution of highfrequency noise

15dB

Frequency components
below 8 kHz band5s

Outside wheel
78.3%Time (s)① Omni-directional
microphone① Accelerometer② Directional
microphone

Track side

① Shaker① From the results obtained in shaker test, the transfer function between
rail vibrations and rail noise is estimated. And, noise contributions frompassage of a train are evaluated.
② The location of the predominant noise source from a passing train is identified.

Fig. 2 Outline of evaluation method12.5 kHzband
10kHz band
Equivalent sound pressure level (dB)for each outside wheel

Fig. 1 Time histories of the wayside noise(At 3.5 m away from the outside rail, curve radius of
2500m, train speed 239 km/h)

22

combining a transfer function between rail noise and rail
vibrations, and source localization technology in the formof a directional microphone. The method was tried on acommercial line which, as shown in Fig. 1, revealed that thedominant source of high-frequency noise was the outside
leading wheel of each bogie (in the traveling direction).
Furthermore, it is found that the level of the noise depends
on train speed (Fig. 3).
The method can be applied to evaluate the characteristics of wheel/rail noise, including high frequency noise,in order to guide the development of mitigation measures.

10dB

Inside wheel
1.2%

Inside rail0%

Outside rail
20.5%

16 kHz band
20kHz band

*230-239km/h

Traveling direction
230-239km/h

250-259km/h

270-274km/h
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Sequential number of cars

Fig. 3 Contributions of high-frequency noise and location of thedominant noise source in the 16 kHz band

Annual Report 2018-2019

Railway Technical Research Institute

20. Train operation power simulator to evaluate energy-saving
strategies• A simulator has been developed that can be used to calculate the energy consumed during train
operation in an actual operating line scale, considering an installing of energy storage systems, under
the condition of several lines and many types of rolling stock.
• The simulator is able to evaluate the performance of energy-saving strategies, such as introductionof new types of rolling stock and energy storage systems.
• The energy-saving performance of an energy storage system was estimated and the influence ofparameters such as outside temperature, is quantitatively analyzed.
Various energy-saving strategies relating to ground sidefacilities and onboard systems are being studied, from theview point of reduction of energy consumption, however, inorder to assess the performance of these strategies, there
is a need for much more accurate energy calculations. A
simulator for calculating energy consumed by trains inoperation has already been developed, which produces
detailed calculations of the current/voltage interaction
between multiple substations and multiple trains, andmake it possible to reflect changes in acceleration due tovariation in voltage to speed profiles. This simulator has
now been modified to include a function that generates

Rolling stock

Current Voltage

Substation

Current Voltage Speed

Notch

Train position

Train diagram

speed profiles to reproduce average driving operations
in commercial traffic. In addition, it can produce practicalscale calculations assuming any type of commercial line,that is, any variety of line, rolling stock, and so on. (Fig. 1).
In terms of energy efficiency, parameters such as auxiliary machine power consumption, running resistance andbraking operation, etc., significantly influence energy consumption calculation results. To resolve this issue, a new
method has now been developed to make use of vehicle
related big data collected through on-board information
recording systems in order to set parameter values thatare as close as possible to reality.
A comparison of actual consumed energy measured during commercial operation on an actual line with estimatedvalues obtained through the new simulator demonstrated
that the reproduction of real conditions had been improved
from a level of accuracy of about 20-10% to within 5%,
confirming a significant step up in performance (Fig. 2).
This outcome demonstrated the applicability of the train
operation power simulator for evaluating energy-saving
strategies.
The simulator was therefore applied to estimate theenergy-saving performance of a newly introduced energy storage device. It was found that its energy-saving
performance varied between 0.7%~3.3% depending on
installation location and outside temperature.

650
600
550
500
450
400
350

Measured(daytime hours)

0Median of measured
value (daytime hours)

Calculated(daytime hours)

10
20
30
Outside temperature [℃]40Fig. 2 Result of energy consumption verification

Annual Report 2018-2019

Energy-saving performance

Energy consumption [kWh]Fig. 1 Example of simulation output display

4%
3%
2%
1%
0%

Installation
Installation
location A
location B
Outside temperature
equivalent 15℃

Installation
Installation
location A
location B
Outside temperature
equivalent 35℃

Fig. 3 Estimated effectiveness of energy storage device

23

Major Results of Research and Development

IMPROVEMENT OF CONVENIENCE
21. Vertical vibration control method for Shinkansen rollingstock• A method has been developed to control vertical and rolling vibrations on Shinkansen trains to improveride comfort.
• The system combines two types of damper and one type of actuator and satisfies the double requirementof improving ride comfort whilst controlling cost.
• Excitation tests simulating actual running confirmed that the maximum ride comfort improvement wasover 4dB(LT value).

PSD of vertical vibration acceleration

The ride comfort onboard
Shinkansen trains has beensignificantly improved following the installation on almost
all trainsets of lateral vibration
control devices. As a result,vertical vibrations can be felt
3
more, and so suitable measures
1
2
are required in response to this.
Vertical vibrations are made up
of “rigid vibrations” produced byController Car body
Accelerometer (bogie frame)
the car body moving as a whole,
Accelerometer (car body)and “elastic vibrations” producedby car body deformation: bothsignificantly impact ride comfort.
Bogie frame
Consequently, a new vibration
Axle box
control method was developed in(1) variable primary verticalresponse to both rigid vibrations(2) variable secondary vertical damper(3) vertical actuator
damperccccc
and vertical elastic vibrations
Fig. 1 Structure of vertical vibration control system and example of position when mounted(Fig. 1).
on bogie
The respective vehicle vibrations are controlled by mounting a variable primary vertical
Peak due to rigid
damper between the axle box and the bogie frame, andbody mode vibration
Peak due tomounting a variable secondary vertical damper between
Without control elastic vibration(LT=85.9dB)
the bogie and the car body. The variable primary verticaldamper controls the elastic vibrations of the car body, while
the other damper mainly reduces rigid body vibrations.
In addition, a newly developed highly responsive vertical
With primary and secondary
actuator is added in between the bogie and the car body tovertical damper control(LT=83.8dB)
further control and reduce both rigid body and elastic vibrations. This method exploits the positive mutual interaction
With all devices control(LT =81.1dB)of these control devices, optimizing vibration reduction /ride comfort improvement. Nevertheless, the three types
0.5
1
2
3 4 5 6 7 8 10of control device can be used effectively in any combination
Frequency [Hz]or alone, and so can be used flexibly in any configuration
depending on the desired ride comfort improvement to be
Fig. 2 Example of how vertical vibration is reduced using
achieved, or cost.
the new method (results of excitation simulating actual
running on rolling stock test rig)
In order to verify the developed method, the devices
were mounted on a Shinkansen equivalent vehicle, andexcitation tests simulating actual running on the rollingstock test rig were carried out. The results confirmed thatthe maximum ride comfort improvement that could beachieved was over 4 dB (LT value) (Fig. 2).

24

Annual Report 2018-2019

Railway Technical Research Institute

22. Aerodynamic brake design for higher Shinkansen
running speeds• A small light-weight aerodynamic brake assembly has been developed composed of a dual-wingresistance plates.
• A computational fluid dynamics (CFD) analysis of the new assembly mounted properly on the roof ofa train set showed that the stopping distance could be reduced by approximately 10% when operatingwith higher running speeds.
Reducing the stopping distance of Shinkansen trains
to improve safety has always been an important topic. In
the case of rain or snow in particular, or conditions that
reduce wheel/rail adhesion (friction force), a new typeof aerodynamic brake has been developed which cancomplement the braking force in emergencies, such as
during an earthquake, etc. The device works by increasing the aerodynamic resistance acting on a running train
when necessary, thereby directly reducing the speed of
the vehicle with a braking method which does not rely onadhesion. This braking system has the specificity that it
generates sufficient aerodynamic resistance when in use,
but is folded back into the passenger vehicles at othertimes, in order to avoid affecting normal operation.
The developed device is composed of one set of two
drag plates, which are designed to stay up alone without
extra support by virtue of differences between the aerodynamic forces of travelling winds generated when the train
is running: the assembly is 65 mm thick, with a mass of 36kg, and is therefore both lightweight and compact (Fig.1).

A prototype was tested in a wind tunnel with a windspeed of 400 km/h. The maximum resistance force of 2.3
kN (3.5 kN in tunnels) on each set could be obtained within
0.3 seconds after sending the operation command (Fig.
2). The durability of the device was tested by deploying
the wings continuously in a speed of 400 km/h over along period of time (cumulative total of 4 hours of windblowing), and no problems were observed, while the tests
also confirmed that no aerodynamic noise was generated
when the wings were stored. Verifications were also madeto confirm the operational safety of the device in low andfreezing temperatures, and in case of a bird strike, etc.
A computational fluid dynamics (CFD) analysis was
carried out by mounting the device on the roof of a 10-car
trainset (Fig. 3). After adjusting the location of the device
on the roof to achieve maximum drag on the whole trainset,
it was demonstrated that the device had the potential of
reducing the stopping distance by approximately 10% witha running speed of over 360 km/h.

Operation by virtue oftravelling wind

Thin

des

ign

65m

m

(a) in storage mode (folded)(b) Drag mode
Fig. 1 External view of prototype

Drag from one set [N]

3000
2294N

2500

Travelling direction

2000
1500

Drag ∝ Squareof speed

1000
500
0

0

100

200

300

400

Speed [km/h]
Fig. 2 Drag characteristics (Wind tunnel tests)

Annual Report 2018-2019

Velocity and pressure distribution
on plate surface
Fig.3 Flow field analysis of train fitted with multiple sets25

Major Results of Research and Development

23. Method for increasing braking force of linear rail brakes• A method for increasing braking force has been designed for a contactless linear rail brake, capableof controlling increases in rail temperature and which can be operated even with loss of power.
• By combining a new design method which exploits distortion in the magnetic field, and a new control
method that employs auxiliary power sources, results found that the new system increased braking
power by a factor of 1.9 compared to the previously used system.

After improvement
Concentrated
winding structure

Iron core coil

Braking force per unit of mass

Before improvement
Ring winding
structure(Equivalent value using state before
improvement as a reference)

In order to reduce the stopping distance of trains operating at high speed, a method for increasing the braking force
of a linear rail brake equipped with an alternating current
electromagnet (armature) has been developed. The linear
rail brake operates in the same way as the eddy current
rail brake, where electromagnetic interaction between thearmature and the rail generates a braking force. However,with the new device, since the energy needed for it towork is generated by the device itself, it can operate evenwhen power is lost, and because of this feature, is alsoable to control any rise in rail temperature. In the existing(previous) designs, ring winding electromagnets were usedin order to control rail temperature (Fig. 1), however, thismeant that there was a limit to the possible increase in
braking force, and reduction of weight. Therefore, basedon a premise of using fewer devices on a trainset in order
to avoid rail overheating, a method was designed thatwould increase the braking force of each individual device.
The new proposed design has a concentrated winding
armature (Fig. 1) and a battery-operated backup auxiliary
power source to enable it to function even with loss of
power. With the concentrated winding structure, by superimposition of distortion onto the sinusoid magnetic fieldon the rail generated by the armature, even though the
maximum rail temperature increase is greater by a factorof 1.8 at the maximum running speed of the Shinkansen
compared to the ring structure, the braking force can beraised by a factor of about 1.5. When the uninterruptible
auxiliary power backup was added to the device combinedwith the energizing system to reinforce the braking force,
tests on the prototype armature demonstrated that thebraking force could be increased by a factor of 1.9, compared to when the device was only self-powered (Fig. 2).
Based on this method, if the braking function of the
trainset is maintained, the number of linear rail braking
devices and the additional weight can be reduced by about
half. Nevertheless, given that the rail temperature rises by
a factor of approximately 1.3, it is being considered for use
in emergencies. Estimations suggest that the rail temperature increase would be higher by approximately 1.8 ℃,
under the condition that the stopping distance using the
new linear rail brakes was be about 10% shorter than using
disc brakes alone, and assuming the longest Shinkansen
train formation being braked from the maximum runningspeed.

2

After improvement(concentrated winding armature,
combined with auxiliary power source)

Before improvement(ring winding armature, self-powered)
1

0
400

300

200

100

0

Speed (km/h)
Fig .1 Schematic drawing of armature structure

26

Fig. 2 Comparison of braking force in relation to mass (roller rig test)

Annual Report 2018-2019

Railway Technical Research Institute

24. Development of a CPS contact wire for Shinkansen• A new CPS contact wire has been developed with equivalent performance of the PHC contact wire
used currently on recently opened Shinkansen lines, and which can be produced in small-lots, at alower cost.
• Tests with the new CPS contact wire on commercial lines showed that the new product posed no
problem from a construction point of view, nor in terms of long term use.
Chromium-Zirconium copper alloy (precipitationhardened copper alloy - PHC®) contact wire with hightensile strength and high conductivity has been introduced
on recently opened projected Shinkansen lines since
the Tohoku Shinkansen line extension (Hachinohe –ShinAomori section) entered into operation. However,the casting and rolling processes for manufacturing PHC
contact wires have to be carried out separately, so eventhe minimum batch quantity should be large. As a result,
this contact wire cannot be adapted to the demand from
infrastructure managers that require only small amounts
to meet their contact line replacement plan needs.
The newly developed Cobalt-Phosphorus copper alloy(CPS) contact wire offers the equivalent performance of
PHC contact wire. This can be cast and rolled successively,
resulting in ability to respond to small quantity of order.

This feature of production procedure also contribute to
reducing cost.
The CPS contact wire was tested not only to determine
its mechanical and electrical characteristics, but also its
wear and fatigue performance, to verify it possessed theequivalent or better characteristics than PHC contact wires(Figs. 1 and 2). Pilot introduction of the CPS contact wireon both conventional and Shinkansen lines demonstrated
that the new product posed no problem in the test use withmeasuring uplift and strain for 6 months after construction,
confirmed that there were no problems in relation to current collection performance including fatigue (Fig. 3). In
addition, confirmation was obtained that this contact wire
had higher resistance to wear than ordinary contact wire
(Table 1).

0.3

Strain amplitude (×10-6)

Rate of wear of contact wire
(mm2/10,000 pantograph passages)

3000
No current flow
(non-energized)
200 A current

0.2

0.1

0

2000
1500
1000
500

PHC110

CPS110

PHC contact wire
CPS contact wire

2500

Means that the test was stopped
before actual breakage of the wire

105

107

106

108

Vibration cycles to fatigue breakage (number of cycles)

Fig. 1 Wear characteristics (stationary tests)

Fig. 2 Fatigue characteristics (stationary tests)

Measuredvalue(maximum)Uplift 35.0mm
Strain 247µst

CPS contact wire

Fig.3 Image of test installation of CPS contact wire on a Shinkansen line and results of dynamic characteristic measurements

Annual Report 2018-2019

Table 1 Results of wear and resistance confirmation tests(from test installation on conventional line)

Type of wire

Annual wear rate
(mm/year)

CPS1100.09

GT-SN1100.13

27

Major Results of Research and Development

25. Yield management method optimizing discount ticket
sales quota• To maximize the revenue of railway undertakings, a method has been developed to optimize thediscount ticket sales quota, based on ticket sales data, etc.
• The method supports the decision-making process for setting the quota, making it possible to maximize
revenue and facilitate decision-making.
One approach for increasing the revenue of railway
undertakings has been to adopt yield management
techniques, by setting a quota for discount ticket salesof reserved seats on express trains. However, the difficulty with this method lies in how to quantify its effect onrevenue, and how to calculate the optimum sales quota
for revenue maximization. Therefore, a method was developed to calculate the optimum sales quota, incorporating
demand estimation for various discount tickets and the
behavior of passengers purchasing the next-best-option
when they are unable to buy their first-choice ticket (Fig.1).
Demand estimation for discount tickets projects ticket
sales per train, segment of journey, ticket type and timeof booking, based on past sales data according to date.
Passenger ticket selection behavior was modelled on the
results from a questionnaire, where imaginary passengers
were asked what their second choice of ticket would bewhen their first choice was no longer available: decideto choose an earlier train, a later train, a higher-priced
ticket on the same train, or abandon the train journey.
This model shows how difference in price between ticket
types and time between trains influences passenger
choice of ticket. This method was integrated into a system,

which can calculate the ticket sales quota and support thedecision-process for setting the quota (Fig.2).
This method and system were then applied to ticket
sales for a particular express train line as a pilot test by
inputting the calculated sales quota into the actual seatreservation system. The result demonstrated that, which
may include other effects, the calculated quota increased
revenue by approximately 5 to 11% compared to manuallyset quotas.
This method supports the decision-making process forsetting the discount ticket sales quota, making it possible
to maximize revenue and facilitate decision-making.

Demand estimation

Solving the mathematicaloptimization problem considering
the booking behavior ofpassengers

Demand for tickets per train,
segment of journey, ticket type
and time of booking

Booking
Success

Calculated quota (per train)
Success / Failure
depends onsales quota

Different
train / ticket
type chosen

FailureReselectionof train / ticket
type
Ticket choice
behavior model

No selectionof alternative

Lost demand

Purchased (i.e. revenue)
Fig. 1 Developed method for calculating optimal
discount ticket sales quota

28

Month / Day Express train No. xxx
Journey segment Ticket type X Ticket type Y Ticket type Z
Station A → B

2 tickets

7 tickets

10 tickets

Station B → C

5 tickets

12 tickets

21 tickets

Optimal sales quota per day/per train based on estimated demand(Also possible to calculate expected revenue)
Fig. 2 Example calculation of quota applying developed system

Annual Report 2018-2019

Railway Technical Research InstituteBASIC RESEARCH

26. Head car collision testing and numerical simulation• The crash deformation and fracture behavior of a rail carbody structure were determined in a crashtest conducted on an actual-size partial railway vehicle.
• Comparison and verification of the simulation output with results from an actual vehicle test confirmed anincrease in accuracy of numerical simulation results and a maximum deformation error of approximately
10%.
• Simulation can be used for examining safety improvement measures to better protect passengers
and railway staff.
When investigating measures to reduce injuries to passengers and railway staff in the case of a collision accident,
tests involving full-scale trainsets are difficult to conduct
because of large scale, and so numerical simulation isan effective alternative, but if simulation is used, then accuracy is essential.
Therefore, in order to increase the precision of simulation, a crash test was conducted on a full-scale partial
vehicle structure. The test vehicle was cut out from astainless steel used head car carbody. A special running
carriage was built to mount the test vehicle, and a highLoad cell

Rigid wall

54km/hRunning carriage

Target markFig. 1 Deformed shape of an actual-size partial vehicle(high speed camera image)energy crash test was carried out. The test vehicle collided
with a rigid wall at a speed of 54km/h. This speed wasestablished on the basis of a statistical analysis of past
serious level crossing accidents in Japan. The results ofthe test were used to quantitatively investigate the crashbehavior of the carbody structure, such as deformationand fracture of the main structural elements (center andside sill, etc.), as well as the crash load/deformation characteristics (Figs. 1 and 2).
A comparison of results from an FEM analysis using
the same conditions as in the crash test with the actual
test results showed that by reflecting various material
properties, i.e. strain-rate dependence obtained from tensile tests carried out at various speeds, and spot and arc
weld rupture characteristics etc., in the FEM model, it waspossible to reproduce the carbody’s deformation behavior
and load/deformation characteristics with high accuracy. As
a result, the maximum load error was approximately 12%,and the maximum deformation error was approximately
10% (Figs. 2 and 3).
This method therefore makes it possible to examine thevarious types of crash behavior of carbody structures that
occur in a collision accident.

FE Result 1 : Not taking into account strain-rate
dependence and weld rupture
2500
FE Result 2 : Taking into account strain-rate dependence
Not taking into account weld rupture
FE Result 3 : Taking into account strain-rate
dependence and weld rupture

Load (kN)

2000
1500
1000
500
0

Test result
0

200

400

600

800

1000

Deformation (displacement of target mark)(mm)
Fig. 2 Comparison of load/deformation characteristic between
test and FE results. Taking into account material and weld
properties, FE result agrees well with test result.

Annual Report 2018-2019

Fig. 3 FE result of deformed shape of test vehicle.
FE result agrees well with test result.

29

Major Results of Research and Development

27. Snow accretion simulation method for high speed
trains• A new snow accretion simulation method to calculate the shape of snow accretion on high speed
trains was developed by combining an airflow simulator with a particle simulator.
• The capacity of the snow accretion simulation method to reproduce the shape of snow accretion a
cubic model was confirmed.
• This snow accretion simulation method can be used to find train shapes that reduce snow accretion.
Snow thrown up from passing trains accumulates andgradually collects on train bodies and bogies. When thisaccumulated snow falls off a running train, it can cause
flying ballast, which in turn can cause damage to signaling
equipment or train bodies. As a means to explore anddevelop measures to prevent snow accretion therefore, asnow accretion simulation method has been developed
which can reproduce the snow accretion process.

The newly developed simulation method combines anairflow simulator with a particle simulator (Fig. 1). The
simulation process follows a series of steps: ① The
distribution of the velocity of the airflow are calculatedaround the target object using the airflow simulator. ② The
trajectories of the flying snow particles are calculated using
the velocity of the airflow. ③ Snow accretion is calculatedaround the target object using the particle simulator. Given
that the target object shape will change as snow
① Airflow Calculation using the airflow simulator
accumulates, the shape is updated, and the calculaDistribution of the velocity
tions in steps 1-3 above are repeated to obtain theof the airflow velocity
snow accretion shape on the object. The capacity② Trajectory calculation of flying snow particle
using the equation of motionof the snow accretion simulation method to reproModification of thefor drag and gravity
boundary shapeduce a shape similar to that formed during snow
③ Snow accretion calculation
Orbit of snow particles
accretion experiments was validated using snowfall
using particle simulator
wind-tunnel experiments (Fig. 2).
Figure 3 shows the results of the snow accretion simulation on a train model. The white dotsshow the collected snow, while the color of streamlines indicates the magnitude of air flow velocity.
Fig. 1 Outline of the snow accretion simulation method
This snow accretion simulation method makes
it possible to obtain insight into the relationshipbetween airflow and snow accretion, and if applied
to the actual train shapes, can be used to find train
shapes that reduce snow accretion.
Experiment

Simulation
Airflow + Snow

Airflow + Snow

Fig. 2 Comparison for a cubic model between the snow accretion
experiment and simulation
Airflow + Snow

Velocity (m/s)

28Fig. 3 Snow accretion simulation for a bogie model

30

Annual Report 2018-2019

Railway Technical Research Institute

28. Ground-to-train communication system using 90 GHz
band millimeter-wave• It has been demonstrated for the first time in the world that ground to train data transmission at 1.5Gbps
using a 90 GHz band millimeter wave is possible at a running speed of 240 km/h.
• This technology can be used to transmit on-board camera images and train state monitoring data
to the ground in real time, and to provide on-board passenger services such as internet access andstreaming video content, etc.
Train radio systems used today have a narrow bandwidth of several kHz per channel, limiting the data rate thatcan be transmitted. As such frequency bands with wider
bandwidths of several hundred MHz to several GHz were
explored, which could be used to transmit large volumes ofdata. Consequently, attention was focused on the 90 GHz
band millimeter-wave which has not been used up until
now on the railways, and the component technologies weredeveloped for a ground-to-train communication system.
Based on measurement experiments carried out on
viaducts and tunnels, and simulations, it was found that the
90 GHz band millimeter-wave propagation characteristics
in the railway environment possessed certain features,such as the lower than free-space . The data relating toweather related attenuation (due to rain fall and/or snow
adhesion, etc.) needed for the design of a radio circuit

was then collected. A new ground-to-train communication
system (Fig. 1) was proposed that combined the 90 GHz
band millimeter-wave with Radio over Fiber (RoF) technology, which was then tried out in a demonstration test.
Test results showed that aside from a change in the datatransmission rate at one point due to a different antenna
angle, track side radio access units (TS-RAUs) connectedto the base station were switched at high speed using an
optical switch, in accordance with the train running at a
speed of about 240 km/h. Consequently, it was verified
that data transmission rate was maintained as transmission moved on from one TS-RAU to the next, and that it
was possible to continuously transmit data up to a rate of
approximately 1.5Gbps (Fig. 2). The results of simulations
to estimate radio transmission quality also showed thatthe new system could probably be used at speeds of over
300 km/h.
Base station
These outcomes suggest that the new
Optical switch
ground-to-train communication system could
allow transmission of up to 750 times moredata than is possible with existing systems.
Radio over Fiber network
Track side radio access
Consequently, with the new system it would beunit (TS-RAU)
90 GHz band
possible to stream train condition monitoring
millimeter-wave
帯
data and security camera images to ground in
On-board station
Train Direction
real time.

Linear cell structure

Data transmission rate (Gbps)

Fig. 1 Proposed configuration of the ground-to-train communication system combining 90 GHz band millimeter wave and radio over fiber (RoF)
2.0

Track side radio access Track side radio access Track side radio access
unit (TS-RAU) 2
unit (TS-RAU) 1
unit (TS-RAU) 3

1.5
1.0
0.5
0.0

0

200

400
Distance(m)

600

800

Fig. 2 Results of the demonstration test

Annual Report 2018-2019

31

Major Results of Research and Development

29. Mechanisms underlying slope collapse due to rain or
during an earthquake resulting from changes in watercontent of volcanic soil
• A constitutive model has been proposed to express deformation and strength characteristics of volcanic
ash soil in case of change in water content.
• Based on simulations of changes in water content and strength of volcanic ash soil due to rain andduring earthquakes, mechanisms underlying tephra-covered slope collapse were clarified.

Pore water

In case of rainfall

Deposited moreloosely thanordinary soil

20
0
-20
40

During anearthquake

0
40
20
0
-20

Increase in water Increase in watercontent due tocontent due toseepagecompression

Fig. 1 Characteristics of volcanic ash soil

Soil/rock(Before rainfall begins)

Volcanic ash soil B

0
10
20
30
40
50
Number of loading cycles [number of cycles]

Fig. 2 Model of behavior of volcanic ash soil during cyclicloading
150
100
50
0
100
90
80
70
1.5

Level of Rainfall
Safety factor saturation intensity[mm/h][%](stability)

Volcanic ash
soil layer

Volcanic ash soil A

20

Axial strain[%]

Soil particles
Pore aircontent was low, repeated loading increased pore waterpressure and could lead to liquefaction (Fig. 2). A model
was then proposed to express the variation in strengthand deformation characteristics depending on changes
in water content of the soil. This was then incorporated
into a coupled permeation – deformation computational
analysis considering the three phase conditions of soil/
water/air. Then, after carrying out a numerical analysisof an actual slope collapse it was found that an increasein water content within the volcanic ash soil layer caused
slope stability to decrease, leading to deformation (Fig. 3).
By applying the mechanical tests which can take
into account changes in water content together with thenumerical analysis method, it was possible to clarify themechanisms involved in volcanic ash soil slope collapse
in case of rainfall and during earthquakes.
Pore water Loadingpressure
stress[kPa][kPa]

Recent years have seen significant damage to tephracovered slopes due to rain and earthquakes. Volcanic ash
soil covers approximately 40% of Japan’s land surface,
and is different from ordinary soil and loosely deposited.
Therefore, it has a water content which varies easily incase of rainfall and during earthquakes. Consequently,
changes in deformation and strength characteristics of
volcanic soil due to variations in its water content need to
be clarified in order to examine the mechanisms involvedin collapse of slopes constituted of this type of soil (Fig.1).
Mechanical tests were carried out on various types of
unsaturated volcanic ash soil to examine changes in watercontent while subject to a load, in order to understand thestrength and deformation characteristics of volcanic soil.
Through these experiments it was found that an increasein water content reduced strength, and that even if water

Slope collapse(after 15 hours)

1.0
0.5
0

Slope collapse occurs

Increase in saturation

Decrease in safety factor (stability)

6
12Time (hours)

18

Fig. 3 Collapse mechanism of tephra-covered slope

32

Annual Report 2018-2019

Railway Technical Research Institute30.Factors influencing concrete deterioration due toexpansion• We found that alkali-silica reaction (ASR) contributes to delayed ettringite formation (DEF) progression,
which is one of the factors leading to expansion deterioration in concrete.
• This has revealed the need of maintenance management that takes into account the compound causesof deterioration of concrete structures in ordinary environments.

Ettringite

20μm

water, causing cracking similar to that of actual concrete
structures. These results indicated that similar cracks could
appear due to complex deterioration in concrete structureseven in ordinary environments (Fig. 3). DEF occurs inconcrete structures with a history of early exposure tohigh temperatures during construction, which could beaccelerated by the decrease in the pH of the concrete.
Thus, we suggested that the influence of DEF should betaken into account during repairs.

3 With ASR
2

DEF isaccelerated
due to ASR

1
0

13.0

0

12.9

Without ASR

100
200
Days passed (days)

300

12.8
12.7

(a) expansion rate

expansion rate [%]Fig. 1 Examples of concrete deterioration due tocombined action of DEF and ASR
3

pH decreases
due to ASR

pH

Ettringite generationin cracks etc.

expansion rate [％]Delayed ettringite formation (DEF) is one of the causesof concrete deterioration. DEF occurs when high temperature environments decompose a cement hydrate called
ettringite produced inside concrete. This then regenerates over time, leading to expansion cracks in concrete.
Previous studies have reported cases of suspectedcompound deterioration of alkalis-silica reaction and DEF
in concrete railway structures (Fig. 1). However, research
conducted on conditions that accelerate DEF has failed toclarify the probability of DEF generation in concrete structures in ordinary environments or demonstrate whether
ASR had any influence on the occurrence of DEF.
Consequently, we investigated this influence, and foundthat decreasing pH in concrete when ASR occurred, created an environment where expansion of concrete due
to DEF occurred more easily (Fig. 2). Similarly, we foundthat ASR deterioration encouraged DEF expansion even in
ordinary environments with a low presence of sulfate andWith ASR Without ASR(b) pH

Fig. 2 Effect of ASR on DEF expansion(under unfavourable conditions)
Deterioration due to combined
action of DEF and ASR

2With ASR

1
Without ASR
0

0

200
400
Days passed (days)(a) expansion rate

10mm(b) Crack stateFig. 3 Effect of ASR on DEF expansion (under ordinary conditions)

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News
Release
1. WCRR 2019 Headquarters Launched
The Railway Technical Research Institute (RTRI) will co-host, with international organizing committee
members, the 12th World Congress on Railway Research (WCRR 2019) which is scheduled from
October 28th to November 1st in 2019. Since last year, the preliminary office for WCRR 2019 has beenworking, and on April 1 this year, the WCRR 2019 Headquarters were launched at RTRI, staffed withnew members. At its opening ceremony, RTRI’s President Kumagai and General Manager Uzuka who
leads the Headquarters’ team made following statements.
President Kumagai’s greetings
Here the WCRR 2019 Headquarters were launched.
The countdown has already started for the congress which
is 18 months away. Since WCRR’99 was held in Tokyoin 1999, the role of WCRR congresses have graduallychanged while Japanese railway systems and technologies
have made great strides. The coming WCRR 2019 will beable to provide participants from abroad with a significant
opportunity to see the Japanese railway systems and toshare views and information. I hope that the team of theheadquarters will think hard and create an inspiring andproductive congress. The entire staff of RTRI will back up
the team.

General Manager Uzuka’s statement
WCRR 2019 Headquarters made a start with sevenmembers. Considering the advancement of Japanese
railway systems into the global market, It is highly importantto have an occasion where railway engineers and managers and executives of railway operators from around theworld gather together. The headquarters team will dedicate
efforts so that the participants will be able to have wonderful“customer experience.”

General Manager Uzuka (center left)

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President Kumagai (center right)

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Railway Technical Research Institute

WCRR congresses have been held since 1994 andworld’s railway engineers and people in railway management have participated together. WCRR has missions topromote railway technical research and development, toenhance the values and benefits of railways and to offer

opportunities for international cooperation. The congresses
have been organized by the WCRR Organizing Committee
consisting of UIC, SNCF, DB, Trenitalia, RSSB and TTCI
which lead world’s railway research.

WCRR 2019 will be a good opportunity to showcase
Japanese railway technologies in addition to provide theplace for information sharing. WCRR 2019 is the second
one held in Tokyo, following WCRR ’99.

Call for Papers and the brochure for sponsors andexhibitors are scheduled to be released in the end of April
this year. The abstracts for presentation will be called in
May and we would like to ask for your participation as
sponsors and exhibitors.

With the main theme of WCRR 2019, “Railway research
to enhance the customer experience,” participants fromrailway operators, industries and research institutes are
expected to deliver presentations which contribute toimproving the experience of railway customers from theirown standpoints.

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http://wcrr2019.org/

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News Release

2. ICT Innovation Project Launched
The Railway Technical Research Institute (RTRI) started the ICT Innovation Project.
1. Purpose
According to the report by the ICT Promotion Team set up in June 2017, the ICT Innovation Project aims to implement R&D to provide solutions for railway technical issues and to promote innovation by using ICT (Information andCommunications Technology).
2. Responsibilities
ICT Innovation Project will fulfill the following responsibilities.
・To set the direction of the R&D to apply ICT to railway systems
・To choose research topics regarding ICT and prepare the roadmaps
・To examine how to implement the R&D on ICT and how to use the research resource
Targeted topics for ICT application are shown in the figure below.below.

Safer train operation
・Autonomous driving using the object-detection technology
・ ICT-supported operation control and autonomous driving which stops trains, reduce the speeds, or movetrains to safer spots according to the situations
Automated operation
・Energy-saving operation, flexible operation meeting delays and changing demand, autonomous driving
Automated maintenance・ Diagnosis of facilities based condition-monitoring data, analysis of big data, machine learning, simulation,
condition prediction combined with cross-sectoral database, automatic maintenance planning
Shared platform
・ Safe and flexible operation, automated operation, the information network for automated maintenance,
operation management system integrating facilities conditions and train positions

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Railway Technical Research Institute

3. Organization
ICT Innovation Project consists of researchers in the broad-ranging technical fields under Project Manager Kumagai,
President of RTRI.
Norimichi Kumagai Project Manager
				President
Kimitoshi Ashiya
Deputy Manager
				Executive Director
Shigeto Hiraguri
Working Leader
				Deputy Director
				
Research and Development Promotion Division
Atsushi Furukawa
Director				Research and Development Promotion Division
Yuichiro Takata
Chief Manager
				Research and Development Promotion Division
Minoru Kondo
Senior Researcher				
Drive Systems, Vehicle Control Technology Division
Masayuki Koda
Director
				Structures Technology Division
Mitsuru Ikeda
Director				Power Supply Technology Division
Katsumi Muramoto Director
				Track Technology Division
Yosuke Tsubokawa Senior Researcher				Track Geometry and MaintenanceKunihiro Kawasaki
Director				
Signalling and Transport Information Technology Division
Masato Ukai		Principal Researcher				
Signalling and Transport Information Technology Division
Hideki Arai		
General Manager
				Signalling Systems
				
Signalling and Transport Information Technology Division
Kazuki Nakamura
General Manager
				Telecommunications and Networking				Signalling and Transport Information Technology Division
Nozomi Nagamine
Senior Researcher				Image Analysis and IT
				Signalling and Transport Information Technology Division
Masamichi Sogabe Director				Railway Dynamics Division
Chizuru Nakagawa Senior Researcher
				Ergonomics
				
Human Science Division

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News Release

4. Overview of the 1st meeting
The ICT Innovation Project had its first meeting on April,
20. At the meeting, after President Kumagai’s remark, thedirection of using ITC was discussed and the following
was proposed:
A road map of the automated train operation and maintenance needs to be prepares.
How to share basic technologies including machine learning and big data analysis should be discussed.

President Kumagai’s remark
Following the report by the ICT Promotion Team, several
research projects have already been started this year, andin December last year, Image Analysis and IT Laboratory
was set up. I hope that this ICT Innovation Project will show
the direction and schedule of research and development
and the picture of future railways, and actively communicate information. We would like to have steady, open andlively discussions.

5. Schedule
The goals and effects of using ITC will be discussed anda research map showing the topics, processes and timeschedule of the research on how to use ICT.

The 1st meeting38

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Railway Technical Research Institute

3. RTRI Updates Its Super Computer
The Railway Technical Research Institute (RTRI) introduced a new supercomputer and its opening
ceremony was held on May 18. With this machine, we will be able to run simulation programs to analyze
railway technical issues with more reality and to provide more practical and direct solutions. It will also
be used for the research to apply information and communications technology to railway systems.
The new supercomputer, Cray XC50, was chosen
based on its processing capacity, cost, compatibility withcurrently-used applications and versatility. It has five times
faster processing speed than the replaced machine. (Table
1)

On this machine, the massive parallel numericalsimulator and ISV application will be run and a variety ofphenomena regarding railways will be analyzed.

President Kumagai of RTRI and Mr. Mamoru Nakano, President of Cray Japan Inc.
at the opening ceremony

President Kumagai’s greetings at the opening
ceremony
After the research over 18 months, our new supercomputer started operation Today. Thanks to the effortsof Cray Japan Inc., we have introduced an extremely

Annual Report 2018-2019high-performance machine. In addition to this advanced
tool, we will have to use our wisdom and intellect so that wewill continue research to enhance safety and technologyof railways and fulfill our mission to make railway systems
more attractive. I believe our researchers will produce
significant outcomes by fully utilizing this machine.

39News Release

Table 1 Comparison of the performance of old and new supercomputers

President Kumagai is booting the CRAY XC50

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Railway Technical Research Institute

4. Proving Test of Superconducting Feeder Cable System
Conducted on JR East Chuo LineThe Railway Technical Research Institute (RTRI) has been developing a superconducting feeder
cable system. This year, under the support by JR East, the team has connected the system to thepower-feeding system of the Chuo Line and conducted power-feeding tests for the first time at home
and abroad. In the testing, it was proved that this system is effective in maintaining stable voltage by
reducing electrical resistance.

Figure 1: Power feeding system for the tests and current flow

【Test results】
408-meter-long superconducting feeder cable system
was installed at RTRI’s Hino Civil Engineering TestingStation and its superconducting state was maintained bya cryocooler using liquid nitrogen as a coolant. Then thesystem was connected to feeder cable running from Hino
substation to Toyoda on Chuo Line and test transmission
to Toyoda Rolling Stock Depot was conducted after thelast train service. (Figure 1) In this test, air conditioning
equipment and lighting fixture of ten E233 10-car trainsets
were turned on. While the testing, the measured voltage
showed almost same level of values at both ends of thesystem and it was confirmed for the first time at home andabroad that the voltage drop value measured on existing
feeder cable, 9.41v, was reduced to below 0.02 v. (Figure
2)

Annual Report 2018-2019

It means that the power loss in this 408-meter range
was reduced about 7kW through the transmission by thesuperconducting feeder cable system.

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News Release

Figure 2: Reduced voltage drop by superconducting feeder cable system【The effect of the superconducting feeder cablesystem】
While electricity is transmitted from substations totrains, energy loss is caused by electrical resistance offeeder cable. Therefore, it is required that substations
be placed with a close interval in order to prevent
voltage drop when trains receive power. When a train
applies brake, the kinetic energy of revolving motors isconverted to electricity, sent back to feeder cable, andreused to power other trains running nearby. If the train
is running in a distant position, however, the regenerated
energy cannot be used effectively because resistance offeeder cable increases in proportion to distance.

◇ Part of this project has been supported by the program to promote creation of Innovation and the program
to create future society by the Japan Science andTechnology Agency and the subsidy for railway technicaldevelopment by the Ministry of Land, Infrastructure,
Transport and Tourism.

Since this superconducting feeder cable system canreduce the resistance to almost nothing, it is expected
to be an effective solution to the issue of energy loss.
Going forward, we will confirm the effects through running tests on commercial tracks, using test trains. At thesame time, in order to attain commercially applicable
performance level, we will extend the length of the currently 408-meter feeder cable system and improve thecooling performance of the cryocooler in order to keep
stable superconductivity in the cable.

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5. A Team Launched to Develop Advanced level-Crossing
Obstruction Detection System
The Railway Technical Research Institute (RTRI) set up Team for Advanced Obstruction Detection
System on September 1 in order to promote utilization of the advanced obstruction detection system inlevel-crossing of commercial-service lines.

1. Purpose
RTRI is currently developing a level-crossing obstruction detection system using far-infrared image processing
technology. We will further improve its image processing
technique and make the safety performance as perfectas possible in order to develop a commercially-applicablesystem. This is why the new team was launched and it
is part of RTRI’s commitment to railway innovation using
information and communication technology.
2. Responsibilities
The team will fulfill the following responsibilities. It is atemporary team with a one-year term limit.
・To share the information on the development of othersystems.
・To compare performance of similar technologies
・ To identify issues to be cleared before completing
commercial products (improving image-processing
technique, confirming safety performance)
・ To gather demands and requirements from railway
operators
・To set development targets
3. Overview of the kickoff meeting
The team had its first meeting on September 3. At themeeting, after the remarks by President Kumagai and theteam leader, Executive Vice President Watanabe, their
expected activities and policy were discussed.
【President Kumagai’s remark】
In April, we started ICT Innovation Project and have beenreviewing broad-ranging technical fields from an interdisciplinary perspective. It is important to finish each technicalcomponent in order to produce substantial output for one
research topic. As the first topic of ICT Innovation Project,
we will improve the detection system for level-crossing
obstruction that we have already been developing. This
team will implement research and development with a highgoal of applying the advanced level-crossing obstruction
detection system to commercial railway lines. Through thisAnnual Report 2018-2019

project, all of us will make best efforts to contribute to thesafety of railway transportation.
【Team leader, Executive Vice President Watanabe’s
remark】
RTRI has so far developed several types of level-crossing obstruction detection devices including ultrasonic-wave
type and stereo-image type. However, none of them havebeen used widely due to various reasons. Now, thisteam was set up and we will work toward the purposeof completing commercially-applicable level-crossing
obstruction detection system using far-infrared image
processing technology. We will identify the characteristics
and the performance limit of the system and introduce itto the places where it will fit in. Since the research costand schedule are also important, the team members will
share such information through the project work. As theterm of this team is limited to one year, we would like toimplement well-focused tasks effectively.
【Organization of the team】
LeaderExecutive Vice President
Assistant Leader
Deputy Director, Research and Development
Promotion Division
Director, Signalling and Transport Information
Technology Division
Senior Chief Researcher, Train Control Systems
Signalling and Transport Information Technology
Division
MemberDirector, Assistant Senior Researcher, Researcher
Signalling Systems
Signalling and Transport Information Technology
Division
Director, Senior Researcher, Researcher
Image Analysis and IT
Signalling and Transport Information Technology
Division

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News Release

Kickoff meeting* Level-crossing obstruction detection system using
far-infrared image processing technology
This device detects obstructions in level crossing byanalyzing thermal images taken by far-infrared camera.

44

This is less susceptible to the impacts of weather conditions and sunbeam and does not require lighting. We areusing mechanical learning technology to develop a systemthat is capable to detect any shape of objects with a sizeof 20×100cm.

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Railway Technical Research Institute

6. RTRI Develops a Low-Cost Ballast Track Maintenance
MethodThe Railway Technical Research Institute (RTRI) developed “Ballast Stabilization Method Using
Biodegradable Polymer” as a low-cost ballast maintenance measure to prevent aged ballasted tracks
from subsiding.

【Main features】
・Biodegradable polymer and accelerator are poured into
fine-grained ballast to reinforce the ballast and preventthe track from subsiding and to reduce maintenance
cost.
・The repairing material is widely used as a ground stabilizing material. As it does not cement the ballast too hard,ordinary tamping is still effective to maintain the ballast.

Fig.1 Processing the ballast with biodegradable polymer【Effects】
This method has already been applied to more than
10 spots of railway tracks for the test purpose. At one
rail joint where mud pumping is occurring, the track was
subsiding 20mm in three months (Figure 2), but since thismethod was applied (Figure 3), the ballast has subsided

Fig. 2 Before the method is applied

Annual Report 2018-2019

just 10 mm in two years. This data has confirmed that thismethod has prevented ballast subsidence more effectively
than conventional tamping (Figure 4). At this site, tamping
had been necessary twice a year. After the method wasapplied, no tamping has been necessary for two years andit resulted in 30% cost reduction.

Fig. 3 After the method is applied

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News Release

Fig. 4 Effect of the method【Overview】
In order to fundamentally repair aged, fine-grained
ballasted tracks, the ballast needs to be replaced with newone. However, it is difficult to implement such replacement
due to its high cost, in particular, on lines with smallertransport amount. Therefore it has been required todevelop a low-cost, effective repair method that can beapplied to these lines.
With this method, biodegradable polymer and accelerator
are poured in ballast that has been finely grained overyears and it improves the strength of ballast and mitigatesthe subsidence of ballasted tracks. Ordinary tie tamping
machine is available to apply this method and trains can run
on the tracks one hour after the work. The biodegradable
polymer (polyvinyl alcohol) and the main ingredient of theaccelerator, silicate soda, are commonly used as groundstabilizing materials. Since these materials do not harden
the ballast excessively, ordinary maintenance by tamping

machines still works after this method applied. As ballast
subsidence can be reduced by this method, the tamping
interval is extended and as the result, maintenance costis reduced.
【Work process】
1. The accelerator is tamped in below sleepers by a tietamping machine (Figure 5 (a))
2. Biodegradable polymer is poured onto the ballast, thenadditional ballast is placed, and the sleepers are tamped
again (Figure 5 (b))
3. Mixed with fine-grained ballast, the biodegradable
polymer gets hardened in a few minutes, the fine grainsof the ballast get cemented (stabilized) and stronger,
and trains can run on the track within an hour.
The biodegradable polymer used in this system has
been marketed by Kowa Kasei Co., Ltd. since March 2018.

Fig. 5 Work Process of ballast stabilization method using biodegradable polymer

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7. Chairman Masada Awarded the Gaston Maggetto Medalfrom EPE
Dr. Eisuke Masada, Chairman of the Railway
Technical Research Institute was awarded the Gaston
Maggetto Medal at the 20th European Conference onPower Electronics and Applications (EPE) for his yearsof contribution to the development of power electronics
technology, for the first time as a Japanese. The medalaward ceremony took place on September 18 this year in
Riga, Latvia.

EPE is an European conference where researchersand engineers in the field of power electronics gather fromaround the world. This conference was started in 1985 andits 20th meeting was held this year. The Gaston Maggetto
Medal, award of the highest honor given by EPE, wasestablished in recognition of Professor Gaston Maggettoof the Free University of Brussels, who served as the firstchairperson of EPE conference and made an outstanding
contribution to EPE.

Chairman Masada at the award ceremony

Gaston Maggetto Medal and certificate

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News Release

8. President Kumagai of RTRI Meets with President of French
National Railways
President of the Railway Technical Research Institute (RTRI), Dr. Kumagai, visited the headquarters of
the French National Railways (SNCF) and had a meeting with President of SNCF, Mr. Guillaume Pepy,
and the executives managing technology-related divisions on the research collaboration.
【Meeting on Japan-France collaborative research】
Date and time: October 18, 2018 14:00 - 14:40
Venue:		
SNCF Headquarters in Saint-Denis
Attendant:
Norimichi Kumagai President RTRI
Guillaume Pepy
President SNCF
Dr. Shunichi Kubo Executive Director RTRI
Pierre Izard
CTO SNCF
David Leborgne
CDO SNCF
Carole Desnost
Director of Research and Innovation
Department SNCF
In 1995, RTRI concluded an agreement on researchcollaboration with SNCF and has implemented collaborative
research projects in a number of technical fields. This
meeting started with the greetings by both presidents andthey shared views on research and development for thehighest priority issue, railway safety, and for autonomous
railways, energy saving, climate change and humanfactors. SNCF and RTRI have been promoting projects
for digitalization, TECH4RAIL and ICT Promotion Project,
respectively. Both presidents confirmed that they need toshare the challenges and to cultivate a human networkby exchanging personnel. They also talked about WCRR
2019, the World Congress on Railway Research scheduled
next year in Tokyo.

Meeting of RTRI and SCNF executives

48

Greetings by President Kumagai
It has already been 23 years since the RTRI-SNCF
research collaboration started, and we have had manyright-to-the-point discussions. Sharing technologicalexpertise by the two most advanced railway organizations
means a lot to world’s railway systems. I deeply respect
the active commitment of SNCF to innovative technologies
and President Pepy’s policy to emphasize technology. I
hope to keep sharing our knowledge and experience inimprovement of safety, digitalization, and mitigation ofnatural disasters over the difference between our railway
cultures.
Greetings by President Pepy
I am so pleased that we have been continuing researchcollaboration with RTRI. I hope we will keep doing in-depth
research and learning from each other. We have beenaddressing the research and development to innovate
door-to-door mobility over the years. Since we cannot findready-made solutions anywhere, we will have to explore
them together. Railway industry begins with technology,
and then innovation comes along. Of course we always
have to see customers beyond the technical innovation,
but technology comes first.

President Pepy and President Kumagai

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Railway Technical Research Institute

9. The 8th SNCF-RTRI Collaborative Research Seminar heldin Paris
The Railway Technical Research Institute and SNCF held the 8th collaborative research seminar from
October 17 to 19 this year in Paris.
RTRI and SNCF concluded an agreement on collaborative research in 1995 and, since then, have beencollaborating in many technical fields of research. Thisseminar was organized to present the result of each project
and to have a management meeting where the plan andschedule of the next-phase projects are set. The seminar
took place at the SNCF headquarters in Saint-Denis and
its Innovation and Research Division in Bercy, Paris andwas attended by 20 people including Mr. Pierre Izard, Vice
President, and Ms. Carole Desnost, Director of Innovation
and Research of SNCF and President Kumagai andGeneral Director Kubo from RTRI.

speeches and the researchers made presentations on the
results of 8 current-phase collaborative research projects
and the research plans for the 11 next-phase projects.
The keynote speeches were made by Mr. Valéry
Versailles, Head of Department, Physical Railway System
of SNCF, and Dr. Shunichi Kubo, General Director of RTRI.
Mr. Versailles presented the research and development
policy of SNCF including three goals: catching up latest
technical trend, achieving technical breakthrough andproposing new business model. General Director Kubo
introduced the latest results of RTRI’s technical development mainly focused on improving safety.

(1) Collaborative Research Seminar
At the seminar at the Innovation and Research Division, therepresentatives of both organizations delivered keynote

Participants to the seminar

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News Release

Presentation at the seminar

In the presentation of the 8th-phase project “Predictive
maintenance methods of OCS,” a method to predict thewear of contact wire and the possibility of applying it topredictive maintenance for contact wire was presented.
As a 9th-phase research plan regarding digitalizationof railways, the researchers reported that they will share
information on the research into on-board train position
detection and trouble detection technologies.

At the end of the seminar, the representatives of bothparties signed the minutes describing what was agreed.
The participants took tours to the Technicampus ( training center) and Centre d’ Ingénierie du Matériel (vehicle
technology center) of SNCF in Le Mans and had discussions with the engineers there.

Mr. Valéry Versailles and Dr. Furukawa signing the minutes

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Railway Technical Research Institute(2) Management meeting
Vice President Izard and President Kumagai joined
the management meeting and the status of research anddevelopment on digitalization of railways was reported byboth sides. SNCF introduced the outline of the TECH4RAIL
project promoted since 2010 and RTRI reported the activities of its ICT Innovation Project. SNCF and RTRI agreed
that they will focus on the following four topics and confirm
the progress, having a management meeting every year.
①Autonomous railway operation
Obstacle detection

Operation control
From human to machine: which will ensure safety? (AI)②Natural disaster, climate change (typhoon, heavy rain
and flood)③Energy④Human factor and safety
The next collaborative research seminar and the management meeting will be held in the fall of 2020 and in thesummer of 2019 respectively, both in Japan.

Participants to the management meeting

Management meeting

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News Release

10. The 58th ICE/TC9 Plenary Meeting Held in Tokyo
The 58th Plenary Meeting of the IEC (International Electrotechnical Commission)/TC9 (Electrical
Equipment and systems for railways) (IEC/TC9) took place from November 19 to 22 this year at theStation Conference Manseibashi in Tokyo. The Railway Technical Research Institute (RTRI) has served
as the Japanese national mirror committee for IEC/TC9 and organized the Plenary Meeting in Japanas a host country committee.
51 people participated in the meeting from 13 countries, Australia, China, Czech Republic, France, Germany,
Indonesia, Italy, Korea, Luxembourg, Russia, Sweden andthe United Kingdom.
At the meeting, committee chairperson Mr. Gianosvaldo
Piana Fadin expressed gratitude to the host country Japanand called the meeting to order.
Following Mr. Fadin’s remarks, Dr. Norimichi Kumagai,
president of RTRI, gave welcome remarks.
At the plenary meeting, the conclusions attained throughthe standardizing activities in the year and the progressesof projects are to be confirmed, and decisions are madeto start the review of new standards and to set up thereview system.
At this year’s meeting, the progress of reviews wasreported and discussions were made on starting new

projects. Finally 40 resolutions were made including thedecisions to start vote for the proposal by Japan, standardizing “AC power compensator”, and to set up a new groupled by Japan to standardize “lithium-Ion battery for auxiliary
circuit.”As you may see, decisions were made to start thereview process of new standards where Japan will takethe lead. In addition, since many of Japanese experts participated in the meeting and directly explained the review
activities in Japan, they were able to appeal the role ofJapan in international standardization to the participantsfrom the increasing number of countries. RTRI will use theresults of this meeting in order to deepen understanding ofJapanese railways and to help Japanese railway technologies advance into overseas markets. During the meeting
period, a technical tour to the test facilities at RTRI wasorganized so that the participants from foreign countries
can understand Japanese railway technologies.

IEC/TC9 58th Plenary Meeting52

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Railway Technical Research Institute

President of RTRI Dr. Kumagai welcoming participants【Greetings by President Kumagai】
I would like to thank you for participating this plenary
meeting held here in Japan, and I want to extend mywarmest welcome to you all. All of us at RTRI hope to
produce significant results through the review process ofinternational railway standards and to contribute to creating
better railway systems in the world. Although technicaldevelopment and standardization efforts seem two different matters, the goal of both activities, providing the resultsof serious efforts by researchers and engineers to thesociety, is based upon the same principle. I am expecting
thorough discussion at this meeting that will help building
a better world.

Participants of the IEC/TC9 58th Plenary Meeting

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News Release

Technical tour at RTRI

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11. RTRI’s Researchers win the UIC Global Research &Innovation Awards 2018
Three of RTRI’s researchers won the UIC Global Research & Innovation Awards 2018.
In 2012, UIC started to provide these awards tooutstanding rail engineers and researchers. UIC’s
International Rail Research Board (IRRB) took initiativein creating these awards in order to develop and enhance
railway transportation at the global level and make it more
attractive, cost effective and sustainable. The review
committee for the awards consists of IRRB members andthe awards are given to researchers and engineers fortheir innovative work in six main categories of “Safety
and Security” “Sustainable Development” “Rail systems
technology” “Rail Freight Service” “Passenger Service”
and “Cost Reduction.” In addition, the Award for the Best
Young Researcher and Award for Lifetime Achievement in
Research & Innovation are given to a researcher of age
under 30 and to a person who has contributed to railway
services for many years.
This year’s award ceremony took place on December
7 at the UIC Headquarters in Paris and the following threeresearchers of RTRI attended the ceremony and were
given the awards.

Award Ceremony
Date and time :December 7, 2018 16:00
Venue:UIC Headquarters in ParisAward winners from RTRI
○ Safety & Security Award“Development of Algorithms for Earthquake Early
Warning System Using Ocean Bottom Seismic
Network”
Masahiro Korenaga
Assistant Senior Researcher, Seismic Data Analysis
Center for Railway Earthquake Engineering
Research○ Sustainable Development Award“Prediction for Long-term Behaviour of Railway PC
Girders affected by Creep and Shrinkage of Concrete”
Ken Watanabe
Senior Researcher, Concrete Structures, Structures
Technology Division○ Cost Reduction Award“Development of Contactless OCL Geometry
Measurement System”
Itaru Matsumura
Assistant Senior Researcher
Current Collection Maintenance, Power Supply
Technology Division

By courtesy of P. Fraysseix at UICceremonyAward ceremony
Mr. Matsumura (right end), Mr. Watanabe ( fourth from the right ), Mr. Korenaga (fifth from the right)

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12. The 4th Japan-UK Track Maintenance Workshop Held in
Winchester, UK
On November 22, 2018, the Railway Technical Research Institute and University of Southampton held
the 4th Workshop on Track Maintenance between UK and Japan in Winchester, UK.

Since 2013, RTRI started to hold Japan-UK workshop
on track maintenance in order to pick up issues shared by
Japan and UK and develop them into future joint research
projects. This year’s workshop, the 4th one, was held at
Wessex Centre of Winchester Cathedral in Winchesterand 35 persons from RTRI, 6 universities of UK and Japanand 2 rail operators from Japan participated. They had
discussions regarding issues of railway tracks including
high-speed rail track.
The workshop was started by the welcome greetings
by Professor William Powrie of Univ. of Southampton, andfollowed by 8 presentations from UK side and 7 from Japanside, total 15 presentations. The topics of presentations by
UK included track maintenance of HS1*1, the research into
fiber-reinforced trackbed ballast , test equipment for railway
track, and track design considering the construction ofHS2*2. The presentations by Japanese researchers dealt
with maintenance of Shinkansen, mechanical propertiesof ballast and track vibration.
Through the presentations, they shared information
regarding the latest research output on ballasted track andslab track. The workshop was closed by the remarks by
Dr. Momoya, Head of Track Structures and Geotechnology
Laboratory, and Prof. Powrie and they agreed that ballasted and slab track maintenance and high-speed rail
design are important issues shared by both countries andthey will continue sharing information.

Outline of Dr. Momoya’s closing remark:
Today, we had presentations covering a wide range ofissues on ballasted and slab track. UK and Japan share
the technical issues of both types of tracks and the issues
need further research and development. I would like topropose that the next workshop be held in 2020, at RTRI
or the Univ. of Leeds.
Outline of Prof. Powrie’s closing remark:This has been a very interesting workshop with many
presentations on ballasted track maintenance, high-speed
line design, noise and vibration, We hope to keep in touchwith Japanese researchers toward 5th workshop.

*1 HS1: High Speed One
A high-speed railway line in UK connecting the Channel
Tunnel and Saint Pancras Station in London.
*2 HS2: High Speed Two
A high-speed railway line planned in UK following the opening of HS1. The first-stage line is to be opened in 2026,
connecting London and Birmingham.

Outline of Prof. Powrie’s opening remark:This is the 4h of the UK-Japan track maintenance workshop. At the first workshop mainly the topics regarding
ballasted track were dealt with, but since the 2nd workshop,
we have picked up issues on high-speed rail and slab track.
In the U.K., HS2 project is currently going on and it has
been discussed which of ballasted or slab tracks should
be adopted for HS2. At this workshop, 15 presentations
will be made including that issue. I am looking forward to
productive discussions.

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Railway Technical Research InstituteProf. Powrie making an opening remark

Dr. Momoya making a closing remark

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57

News Release

13. Japan-France Workshop on Scour and technical standards
for basic structures Held in France
The Railway Technical Research Institute and the French Institute of Science and Technology forTransport, Development and Networks (IFSTTAR) held the Workshop on Scour and Erosion from
November 27 to 29, 2018 in France.
Since 2014, RTRI and IFSTTAR have been implementing collaborative research and exchanging researchers
and in 2017, concluded an agreement on collaborative
research.
Currently, following three collaborative research andinformation sharing projects are in progress:
・ Analysis of scouring at river bridge base and soil
erosion・ Comparison of Japanese and French technicalstandards for base and soil structures
・ Information sharing on the methods to analyze
ground-structure dynamic interaction
This workshop took place at IFSTTAR in Marne-la-Valléein the suburbs of Paris, with 30 participants from RTRI,IFSTTAR, Japanese and French universities, research
institutes and railway operators. This was organized toshare the results of RTRI-IFSTTAR collaboration and theexpertise of railway operators in France and Japan.
The three-day workshop was started by the opening remarks by Mr. Kovarik, Deputy General Director of
IFSTTAR, and Dr. Ota, Director of the Disaster Prevention
Technology Division of RTRI. From France, 8 presentations were made on its risk management project for
scour “SSHEAR”*, on-site scour risk management, bigdata analysis regarding scour and others. From Japan,
7 presentations were delivered regarding Japan-Francecomparison of methods to identify scouring risk points,
scour monitoring technologies and examples of scouring
disasters. Discussions were also made regarding scourand erosion risk management and technical standards forbase and soil structures.

in Japan and France. The presentations and discussions
provided us good suggestions for the improvement ofscour risk scoring tables. In the field of technical standards
for base structures, the difference and common points
between Japan and France in vertical pile-loading tests
were reviewed as an information sharing project.
Outline of Mr. Kovarik’s opening remark:
RTRI and IFSTTAR have been working together toshare our expertise and improve the quality of research
activities for the purpose of making railway systems more
resilient, friendly to the environment and fitting to climate.
In this workshop, we will be focusing on the research into
scouring at bridge base and relationship between erosion
and soil properties. I hope researchers from both sides
will have discussions and promote the projects beyond ameeting room.
Outline of Dr. Ota’s opening remark:This workshop will provide us a very good opportunity
to understand the difference between France and Japanin scouring and eroding risk by sharing our expertise. I
am looking forward to having even closer cooperative ties
with IFSTTAR, related universities and institutes throughthis workshop.
* Soils, Structures & Hydraulics Expertise and Applied
Research

With regard to bridge base scouring, examples ofscouring and inspection methods were presented as well
as RTRI’s scoring tables, scour guidelines in France andthe results of comparison and confirmation, followed byproductive discussions on the difference between bridge
structures, riverbed, flow speeds and inspection methods

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Annual Report 2018-2019

Railway Technical Research Institute

Deputy General Director Kovarik

Participants

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59

VisionWe will develop innovative technologies to enhance the rail mode so that railways
can contribute to the creation of a happier society.

Missions
We will accomplish the following three missions:
To intensify research and development activities so as to improve railway safety, technology andoperation, responding to customers'needs and social change.
To develop professional expertise in all aspects of railways and, as an independent and impartial
research body, to fulfil our tasks using the best science available in an ethical way.
To pioneer cutting-edge technologies for apanese railways and become a world-leader.

Research and development
responding to customers’ needs

Independent and impartial
research using the best scienceavailable

RISINGWe will develop innovative technologies
to enhance the rail mode so that railways cancontribute to the creation of a happier society

Leading the world's
railway technologies

Management and administration

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Annual Report 2018-2019

YEAR 2018-2019: April 1, 2018 - March 31, 2019
Copyright© 2019 Railway Technical Research Institute.
All rights reserved.
Published by Kimitoshi ASHIYA, Executive Director
International Division, Railway Technical Research Institute
Hikari-cho 2-8-38, Kokubunji-shi, Tokyo 185-8540 JAPANFind us :WEB: https: //www.rtri.or.jp/eng/index.html
Facebook: https://www.facebook.com/rtri.eng

For download :Brochure & Annual Report: https://www.rtri.or.jp/eng/rtri/brochure.html
Other Publications: https://www.rtri.or.jp/eng/publish/