At maintenance work of switching equipment, fixing force between a tongue rail and a stock rail is managed indirectly by opening force on toe of a tongue rail, because it had been known empirically that these forces are proportional. In our studies, it was confirmed that these forces have proportional relation in many cases of measurements and simulations, however the relation are affected by a closure status between rails and measurement method of opening force. In this paper, we report the test results for investigation that the effects for strains of switching devices and lateral displacement on toe of a tongue rail against fixing force strength, when vehicle passed on a turnout. By the test results, we confirmed that the effect of the strength is small for those parameters in normal fixing force between 1.9kN to 3.0kN. In addition, we propose new standards and methods for maintenance work of fixing force based on this study.

Stochastic evaluation of the track buckling is achieved considering the random process of initial lateral misalignment of continuous welded rails. The probability density functions are obtained by means of the subset simulation. The stochastic influence of statistical parameters in the autocorrelation function of the lateral irregularity on the upper and lower buckling temperatures is investigated. Influence of the uncertainty in lateral resistance on the probabilistic characteristics of the buckling safety is also examined.

In recent years, some prestressed concrete sleepers (PC sleepers) installed in areas with a high risk of frost damage have some deformations that are considered to be frost damage, such as scaling and fine cracks. Therefore, efficient maintenance and management methods for these PC sleepers with frost damage are required. To establish appropriate replacement plan for PC sleepers with frost damage, it is necessary to clarify the actual temperature environment around the PC sleepers. In this study, temperature environment investigation of PC sleepers installed in areas with a high risk of frost damage are conducted. As a result, the effects of sunshine and snow conditions on the temperature environment and the number of freeze-thaw cycles of PC sleepers.

A track irregularity on a turnout section is difficult to measure by a track inspection car due to a gap called “whiteout” on a crossing section. However, the demand of developing the way to measure the track irregularity on the turnout section increases by the railway companies. In this paper, we introduce a method to remove the whiteout on the turnout section from a track measuring data of a track inspection car and track irregularity monitoring device, and study on a possibility of application of this method to evaluate the track irregularity on the turnout section.

A literature survey was carried out to identify possible sources of lead soil pollution of land, including railway sites, due to external environment other than the railway industry. Examples of possible sources from the railway industry were investigated to assess their impact and to examine whether it is technically feasible to distinguish whether the source is from the railway industry or not. It was found that, at present, lead emissions from road traffic are high, but that these external sources are decreasing.

In recent years, there has been a strong demand for reduction of energy consumption from the viewpoint of preventing global warming, and reduction of energy consumption associated with the running of railway vehicles is no exception. When formulating an energy-saving plan for a railway company, a method to estimate the energy consumption associated with the running of a vehicle is required. In this paper, we briefly introduce the simple calculation method for electric and diesel railcars proposed in the past and propose a new simple calculation method for hybrid diesel railcars constructed by combining the previous method.

We developed a driving support system of high-speed trains that ensures the punctuality and controls the driving to save energy. This system has a function which creates a run curve ensuring punctuality and operates the train to run along the run curve. It is mainly composed of a run curve creation unit and a notch selection unit. The run curve creation unit creates a run curve that saves energy by adding longer coasting. The notch selection unit selects optimal notches with better equipment efficiency to save energy. As results of conducting running tests of this system by using the Series N700S prototype train for the verification, we confirmed sound performances in punctuality and energy saving that we expected.

It is known that a pressure fluctuation with frequencies of several hertz to 100 Hz are generated from a passing Shinkansen train vehicle. Past studies showed that this aerodynamic pressure fluctuation is caused by bogie cavities and gaps between vehicles. To evaluate the pressure fluctuation, we have utilized a linear microphone array for field measurement. The microphone array consists of ultra-low frequency microphones arranged in line along the rail. In this paper, the effect of the microphone arrangement of the linear microphone array on measured results of the pressure fluctuation was investigated in cutting section.

Railroad companies have prepared safety system to prevent a fall accident from station platform such as emergency stop buttons, fall detection mats, waiting spaces under platforms and platform doors. In particular, platform doors can almost eliminate fall accidents, except for cases where people climb over them and enter the tracks. However, various types of platform doors have been developed because platform doors installation has some problem such as the differences in door positions between vehicles and the cost of installation. Hence, we developed a gate-bar typed safety device to prevent a fall accident from a station platform as an alternative safety system to platform doors.

In recent years, the interior lighting of railway vehicles is changing to LED lighting. LED lighting has dimming and toning functions, which makes it possible to create an unprecedented in-vehicle environment and may contribute to in-vehicle comfort. In this study, we examined the possibilities of various functions of lighting. We also conducted multiple evaluation tests to verify the specifications and expected effects that lead to improve in-vehicle comfort.

This paper describes displacement-dependent rubber bushes applied for traction links to reduce elastic vibrations in Shinkansen vehicle. The developed rubber bushes have a small gap between the rubber and the inner fixture, which realizes the rubber bush with displacement-dependent properties. The transmission of excitation force from bogie to carbody is isolated by the gap. We confirm the vibration isolation performance and running stability of the developed rubber bushes by excitation tests using a bogie and test vehicle in the rolling stock testing plant.

Railway operators’ revenue from passenger transport fluctuates in accordance with various factors. However, the impact of those factors on the fluctuation is unclear. Therefore, we try to quantify such effect, focusing on the impact of opening and renewal of shopping complexes near the station. For this purpose, “Causal Impact,” a time series causal inference method, is applied to aggregated revenue data. As a result of some case studies for some stations, it is suggested that opening of shopping complexes can contribute to the increase in nearby railway station revenue.

When using railway, passengers wait at stations for their trains to arrive. The length of waiting time may depend on characteristics of train timetables, as well as travel characteristics and personal preferences. This study attempts, by focusing on timetable characteristics, to reveal the effect of introducing clockface timetables on reducing passengers’ waiting time at stations. The questionnaire data and regression analysis suggest that, besides train frequency, waiting time is significantly shorter in stations with clockface timetables than those without.

The purpose of this study is to analyze the transition of the staying population during heavy snowfall in the Tokyo area in January 2018 using mobile spatial statistics based on the location information of mobile phones. As a result of the analysis, after 14:00 when the heavy snow warning was issued, the population increased in many municipalities compared to normal times, while it decreased in work areas such as central Tokyo compared to normal times. In particular, in the 5 central wards of Tokyo, the population decreased significantly from 16:00 to 18:00. Furthermore, it was found that those who had a long distance from their place of stay to their place of residence started returning home early.

This report focuses specifically on EU's Shift2Rail, which is a major railway R&D project and its promoting organization in Europe, and summarizes its process of establishment, its composition of R&D organizations and its scheme of the evaluation. Through this process the current European R&D system, railway's system development direction and the future direction of R&D to be carried out by Japanese organizations are clarified as follows. Firstly, this project is characterized by having future-oriented research programs for example. Secondly, the goals are numerically declared, and the research activities are evaluated using the achievement levels named TRL. Thirdly, each R&D program is systemized with the smallest components named TD and BB.

The number of railway service disruptions has been increasing owing to intensification of natural disasters. In addition, abrupt changes in social situations such as the COVID-19 pandemic require railway companies to modify the traffic schedule frequently. Therefore, automatic support for optimal scheduling is anticipated. In this study, an automatic railway scheduling system is presented. The system leverages reinforcement learning and a dynamic simulator that can simulate the railway traffic and passenger flow of a whole line. The proposed system enables rapid generation of the traffic schedule of a whole line because the optimization process is conducted in advance as the training. The system is evaluated using an interruption scenario, and the results demonstrate that the system can generate optimized schedules of the whole line in a few minutes.

The railway network in the Tokyo metropolitan area has been operated with interconnection and high-frequency service to increase convenience. However, the negative effects of these measures have resulted in chronic train delays, and urgent solutions are required. Train delay is a phenomenon in which a train is delayed due to an increase in boarding and alighting time caused by congestion, etc., and has a dynamic nature in that it propagates to subsequent trains. In this study, we develop a recursive logit-type railroad route selection model that represents the dynamic nature of delay phenomena in a space-time network based on timetables, with a view to evaluating railroad delay countermeasures.

When a large-scale natural disaster happens, railway facilities can be affected. In that case, they may be restored, and the operation section will be expanded accordingly. It is necessary to make a transport plan in each expansion phase, which is a heavy work for schedule planners. In this paper, we propose a rolling stock assignment algorithm for supporting schedule planners. The algorithm is based on a multi-commodity network flow model which aims to reduce the number of required rolling stocks and split-and-merge. In addition, we show the result of computational experiments using actual railway data.

When a train service disruption happens, dispatchers make a train rescheduling plan to control train delay and congestion. To support dispatcher's work, we developed a passenger flow prediction model during disruption using machine learning techniques. The proposed model consists of time-series waveform prediction using LightGBM and rule-based correction. We defined 5 time series waveform clusters using unsupervised learning with dynamic time warping(DTW). As a result, we verified prediction average accuracy 75% about 4 cases of unlearned disruptions.

Scouring is a disaster that threatens safe driving of trains. So, we proceed with the development of a new scour detection device is also possible state grasp of before scouring inclined. The natural frequency of the pier is calculated from the measured waveform, and when the value drops, it is judged as scoured state. In order to verify whether the natural frequency can be calculated stably from the constant microtremors, long-term microtremors measurement was carried out. From the calculation results, we verified the long-term stability of the natural frequency calculation and analyzed the natural frequency fluctuation tendency when the water level increased. It was found that the natural frequency can be calculated stably and accurately in daily water level fluctuations where disasters do not occur.

Ultrasonic impact treatment (UIT) is an effective method for improving the fatigue strength of welded joints. In this study, the applicability of UIT to the welded joints of a railway bogie frame was assessed. Fatigue tests and finite element analysis of cruciform welded joint specimens were performed. The results showed that UIT increased the fatigue limit to more than two times that of the as-welded test specimen. This difference was attributed to the increased compressive residual stress and the expanded weld toe radius caused by UIT, as in previous findings. Therefore, UIT can improve the fatigue strength of welded joints of railway bogie frames.

The fatigue strength of back-side welded joints of railway bogie frames has not been clarified. Therefore, three-point bending fatigue tests on T-joint specimens were conducted. In the case of fatigue fracture initiation at the weld toe, the fatigue strength of the back-side welded joint was almost equal to that of the as-welded joint with the same weld toe radius. Moreover, finite element analysis was also conducted to evaluate the fatigue failure initiating at the root area. It was found that the stress intensity factor of the nonwelded area was almost constant at its different lengths, and the fatigue strength of the back-side welded joint did not decrease significantly, even at the nonwelded area.

In the railway field, the shortage of railway drivers and maintenance workers has become a problem, particularly serious for local railways where the business environment is experiencing difficult conditions. Therefore, further efficiency and labor saving of operations are required, and installation of automatic operation to general routes is being considered. Among them, safety measures at level crossings which the points of contact with road traffic are considered indispensable to ensure safety on train tracks. Therefore, we think important to detect crossing rod breakage that blocks road traffic when the train approaches, and we report about the studying of detection method using image analysis by color element.

When a flaking occurs in an axle bearing housed in an axle box, the axle box tends to abnormally vibrate. We have developed an autonomous damage detection system that detects and notifies receiver of flaking of axle bearing by actively utilizing the abnormal vibration of the axle box. The system uses an anti-vibration rubber installed on the axle box. The system consists of piezoelectric elements to convert the vibration to electric power and a transmitter built into an anti-vibration rubber. The transmitter is driven by the electric power from the piezoelectric element to notify the receiver of damage. In this study, to evaluate the detection performance of the autonomous damage detection system we conducted an experiment using the axle bearing fatigue test equipment, after flaking is artificially generated and propagated.

In this paper, we investigate a methodology that estimates derailment occurrence probability during an earthquake through the railway route. The methodology, which is based on the derailment occurrence estimation using track vibration waveform during an earthquake, includes effects of the parameter of railway structures and the existence probability of the railway vehicles due to train diagrams. The trial calculation using the proposed methodology has shown that the train possibly derails when it runs near the epicenter in case of active fault type earthquakes with shallow hypocenter.

Because there is not outbreak of the human damage, the Incident is hard to become a target of social sanctions such as criminal punishment, the administrative deposition unlike an Accident. In addition, I have characteristic to say that the cooperation of the person concerned including the acquisition of the detailed testimony is easy to be provided because the person concerned lives. I suppress the damage as much as possible by clarifying "an element, the factor that was able to prevent an accident" by a railway Incident Investigation and connect it with improvement of the resilience of the railway safety.

The purpose of this study was to formulate criteria for determining the necessity of implementing planned suspension of operations using the measured values of railway rain gauges and the weather prediction information of the numerical weather prediction model. For Typhoon No. 19 in the first year of Reiwa, we analyzed the three points of rain intensity, length of rain duration, and wide range of rain, and examined a method for determining planned suspension of operations by combining them.

The snow accretion simulation consisting of airflow calculation and snow accretion calculation was conducted to verify the reduction effect of snow accretion for railway car-body models. As a result of the simulation, the amount of snow accretion in the countermeasure shape decreased by 44%. The results of the air flow calculation suggest that the amount of snow accretion decreases due to the increase in the flow velocity on the wall surface and the obstruction of the flow toward the upper wall of the bogie.

To discuss about utilization of Hazardous Wind Watch released at the time of typhoon by the Japan Meteorological Agency for railway disaster prevention, authors collected and organized about 6,500 data of Hazardous Wind Watch and conducted a statistical analysis. As a result, predictive values of the Hazardous Wind Watch were evaluated to be approximately 4% on average both at the time of typhoon and others. On the other hand, capture ratios of the Hazardous Wind Watch were evaluated to be up to 75% or more.

Parapets, noise barriers and through girders, hereafter referred to as the wall, which have 100% solidity ratio are not built for the wind protection. However, the wind protection effect can be expected as long as the height of the wall or the distance between the wall and the vehicle meets certain criteria. Then, in order to confirm the wind protection effect, we carried out the wind tunnel tests. On the basis of the test results, we arranged the conditions for the windbreak wall which have a windbreak effect equal to or better than that of windbreak fence (the height is R.L.2m and the distance to the center of the vehicle is 3m).

Fires on railway rolling stock potentially cause not only injury passengers and crew but also damage the rolling stock equipment. It is important to evaluate the performance of materials against fire. Heretofore, the time-dependent production of smoke and toxic gases relating to combustion behavior has not been considered. Moreover, quantitative understanding of combustion behavior is important. From these backgrounds, Railway Technical Research Institute designed and fabricated a new combustion test device that can simultaneously measure time-dependent changes of combustion phenomena through combustion tests. On the other hand, it is necessary to compare the conventional index of toxicity (CIT_G) between EN standards and new combustion test device. Therefore, obtained from respective tests was compared with use of same materials for railway rolling stock.

The authors investigate a method to monitor the running condition of a bogie using an axial spring anti-vibration rubber with a built-in piezoelectric element called "anti-vibration rubber with built-in sensor". In the previous study, it was found that the piezoelectric element in the anti-vibration rubber with built-in sensor move during the rubber molding process. It may affect the performance of the sensor. Therefore, a new piezoelectric element in the anti-vibration rubber with built-in sensor was fabricated to prevent the piezoelectric element from moving during the rubber molding process. In this paper, we report the results of the basic characteristics of the newly fabricated piezoelectric element in the anti-vibration rubber with built-in sensor, such as frequency characteristics and fatigue characteristics.

Double helical gear driving device was contrived newly to realize stable run and high reliability in place of conventional helical gear driving device, because the load on the driving device is increased by high-speed Shinkansen to 360km/h. Therefore we produced some double helical gear driving devices experimentally, and verified performances and long-term durability by some tests using rotation testing machines and the high-speed examination train (commonly known as FASTECH360 and ALFA-X) on main track, and could confirm that it was a good result. In this paper, we describe the summary and characteristics that became clear in the development of the double helical gear driving devices of division type.

In the railway industry, there are needs to develop technologies that contribute to automatic driving and driverless operation in order to address the shortage of drivers due to the declining population and to improve the safety of train operations. Therefore, in order to expand the benefits of driverless operation, Railway Technical Research Institute is investigating an autonomous decentralized train operation system in which the train itself collects information necessary for operation, communicates directly with signal equipment such as turnouts and level crossings, and controls speed while confirming safety.

In this paper, we report on a method of autonomously configuring safe route by onboard equipment. In the conventional method, blocks and routes are secured by wayside block equipment and interlocking device. On the other hand, in the proposed method, the on-board device compares the routes with passage time of its own and other trains and secures the block if its own train is judged to have priority. We also analyzed the effects of control equipment malfunctions on safety.

The radio train control systems have been increasingly introduced. In order to provide flexible operation and reduce the need for ground equipment, the systems use of radio transmission between the ground and on-board trains, and train positioning with on-board databases. However, it becomes difficult to interoperate, when each company has different transmission formats, radio standards and databases. In order to ensure interoperability, we propose the idea for defining the minimum functions required to ensure safety in the radio train control system. In the defined system, interoperability is achieved by replacing the information.

Recently, systems using radio communication for train control or operation assistance have been widespread, and they are contributing to advancement of operations, improvement of safety and others. On the other hand, security of information transmission has become very important. NTSEL carried out a case study using our original equipment for preventing level crossing accidents as a model in order to consider methods of detections and countermeasures against accidental or artificial interference on information transmission. The results of the study were verified by actual train running tests.

This paper propose an on-board position detection method using a combination of a tachometer and an inertial sensor to detect the beginning and end of curves and turnouts. As a result of the driving test, we obtained the prospect of achieving the target accuracy of position recognition error of 4m, which is to be used as a substitute of the position information ground beacon. This paper reports the outline of the proposal method and the test results.

The conventional train control system is based on fixed block to control trains safely. Radio train control system is able to realize the moving block between trains which have same route. However, most radio train control systems use fixed block in stations because the interlocking equipment is same as current system. Therefore, route variable interlocking system has been proposed to control trains more efficiently. It can control trains using moving blocks also in stations. When we introduce that system, it is considered that on-board equipment has to decide priority in conflicting route trains. In this paper, we report a method of deciding priority in conflicting trains when we configure autonomously safe route by on-board equipment.

We have been conducting design safety evaluations of railway signalling systems, considering the consistency with international standards. On the other hand, in order to cope with the recent complexity of railway signalling systems, it is considered effective to utilize new evaluation methods proposed in recent years in addition to the conventional safety evaluation methods. In this paper, we report on a trial evaluation using STAMP (System Theoretic Accident Model and Processes) / STPA (STAMP based Process Analysis) as a new evaluation method.

This study considered the mechanics of snow removal resistance acting on railway vehicles. We researched the running resistance of a vehicle on a snow-covered-track. In addition, we researched factors important to the resistance of snow removal by a scale model experiment using walnut powder and miniature rail guard. From this experiment, we examined the relation between running speed, snow height, width of rail guard and running resistance force on a section of snow. From the results, we propose a method of how to obtain running resistance force on a section of snow from running speed, snow height, and width of rail.

It is important to evaluate current collection performance based on results of a bench test where sliding between overhead contact lines (OCL) and pantograph is considered. This study proposes methodology of hardware-in-the-loop simulation (HILS) for the current collection systems using RTRI’s High-Speed Test Facility for Pantograph/OCL Systems (HiPaC) being in operation since 2020. In the proposed HILS, the contact force between pantograph head and vertical actuator is estimated from strain measured at the pantograph head. It is validated that the dynamic interaction between OCL and pantograph due to span-passing of the pantograph can be evaluated by the proposed HILS.

A series of elastic-plastic FE analyses was carried out to identify the allowable operating temperature of wheels of different diameter with various web shapes. The allowable temperature was determined by the onset temperature of plastic deformation during temperature rise. Circumferential tensile residual stress and residual rim displacement were generated depending on the degree of constraint of displacement, i.e. the shape of the web. The analytical results were in close agreement with the experimental values in the literature.

Most of frictional materials used in railways are constructed from several kinds of materials. Therefore, its material properties largely depend on mesoscopic structure such as ratio, size, shape, and position of each constituent. To clarify the relationship between mesoscopic structure and material properties, the homogenization method using mesoscopic structure model is useful to evaluate equivalent material properties. In this study, as an example of confirming validity of the evaluation by the homogenization method, we compare the calculated material properties with the experimental ones for metal-impregnated carbons. As a result, it is shown that the difference of them is up to 30%. In addition, it is also shown that the dependence of calculated electrical resistivity on metal-ratio is similar to that of experimental ones.

Maintenance or renewal of track circuits detecting train positions is heavy burden for a rail operator. Using Global Navigation Satellite System (GNSS) is one of methods which a train detects its position by itself and would be replacement of track circuits. It is required a preliminary evaluation for the accuracy of train detection position using GNSS on actual railways expected for application of GNSS. We are considering evaluation techniques for the accuracy of train detection position using GNSS.

Signaling systems tend to be installed at a place where vibrations due to train passing are caused via rails, sleepers, and roadbeds. Therefore, it is necessary to design in consideration of the influence of vibration not to be damaged by vibration. In recent years, the installation environment of signal equipment has been changing due to the speedup of trains and changes in tracks and structures. However, the details of the propagation of vibrations to signaling equipments have not been investigated so far. Therefore, we investigate the current usage environment of signaling equipment to grasp the actual situation. In this report, we show the background of vibration measurement so far and the current issues, and report the construction of an unmanned measurement unit and the status of investigations to date.

It has been said that lubricative carbon films are formed on the surface of a contact wire when using carbon based pantograph contact strips. However, there are no reports on the observation of such films, and the details of the carbon film have not been clarified yet. In this study, the author investigated the surface of the worn contact wire actually used on a commercial line where the metalized carbon contact strip is applied. From the results of the Raman spectroscopic analysis, it was found that both R value, the D band /G band ratio, and the width of the G band of the carbon film decreased compared to those of the original carbon substrate of the contact strip. It means that the carbon film on the contact wire is not only a transfer film from the contact strip but also a product of graphitization process on a sliding surface. The author also conducted wear experiments using the metalized carbon contact strip sliding against a copper ring under electric current condition. It was found that such graphitization of the carbon was proceeded by only arc discharge not by Joule heat of frictional heat during sliding.

In this study, we continuously measured rail surface roughness in the track where the rail was corrugated, and resilient rail pad is used on a trial basis. The authors' previous study shows that there are multiple types of growth factors for rail corrugation. In an investigation track, growth factor of rail corrugation was identified as "anti-resonance phenomena in total system of track and vehicle". As a result of the field investigation, it was confirmed that the growth rate of the rail surface roughness of the rail corrugation was controlled in the track by using resilient rail pad as compared with in the track by using conventional rail pad.

Flange wear tends to occur frequently in urban subways where there are relatively many sharp curved sections. This flange wear is the main factor that determines the cycle of wheel turning in the Tokyo Metro. After turning the wheels, the flanges are severely worn in the first few months, and when the flange wear progresses to some extent, the wear rate decelerates rapidly and the occurrence of wear is suppressed. In this study, the contact between the wheel and the rail was investigated with a new wheel and a worn wheel, especially on rails with severe wear. Based on the results of this research, we have developed a new wheel tread that can prevent flange wear. In addition, the developed wheel was put into service on a commercial line and the flange wear was investigated.

On the lines that made use of the characteristics of linear-motor-driven subway "Linear Metro", there are a lot of sharp curves which have a radius of less than 160m. In such sharp-curve sections, optimization efforts in the maintenance for prevention of wear of rails and wheels are continued. A link-type steering bogie was introduced for the first time into a Linear Metro line. Based on the wear situation observed later, a ground-side lubrication device was introduced. The evaluation methods for the prevention of wear are reported.

In this study, in order to clarify the causes of rail fracture at leakage area in tunnels, past cases of rail fracture were analyzed and the causes were estimated. In addition, in order to clarify the effects of head unevenness and floating sleepers, which are considered to be direct causes of rail damage, on the stress generated by rail bending stress, we extracted the locations where these stresses were significantly generated from track survey data and conducted measurement tests of rail bending stress during train running. Based on these results, the mechanism of rail fracture at the leaking area was discussed.