In some cold regions, the freezing and thawing action has caused frost damage to the slab track filling layer. For the purpose of predicting frost damage to slab track, we proposed a temperature prediction method based on a coupled analysis of solar radiation and heat conduction, taking into account the shading of railway structures such as sound barriers. By applying corrections to the proposed method to simulate the effects of snow accumulation and other factors in concave areas, we were able to reproduce the actual temperature of the slab track cross section.

We developed a spring clip fastening system for jointed PC sleepers in low-traffic rail lines. Since the structure fastens the rail at the center of the PC sleeper, there was a challenge in that fastening was not possible when the joint positions of the left and right rails differed significantly. Therefore, we considered extending the fish plates to allow fastening even when the joint positions differ to some extent, and we manufactured fish plates with five holes. We assembled the fish plates and measured the response values generated when the fish plate bolts are tightened in laboratory tests. Additionally, we installed them on the track and measured the stress on the fish plates during train passage.

Among the track geometries, the combination of alignment and cross-level was determined based on the running characteristics of the two-axle freight cars that were operated during the JNR era, so it is not necessarily an optimal index for the rolling stock with two-axle truck currently in operation. Therefore, it is necessary to clarify the range of application to the running safety of current vehicles and to review the composite index. In this paper, as a fundamental study to meet such demand, we analyzed the actual distribution and progress of various track geometries in the current section that manage the combination of alignment and cross-level, and the impact of these track geometries on the vibration of passenger vehicles.

In recent years, a method has been developed to detect floating sleepers using restored track irregularity of vertical displacement by a track inspection car, and this method is being used for track maintenance management. Although this method has been confirmed to have sufficient estimation accuracy in continuous welded rail sections, it has been pointed out that the detection accuracy is low around rail joints in standard length sections. In this paper, as part of an effort to improve the detection accuracy of floating sleepers at rail joints, we report on our investigation into the cause of the decrease in the detection accuracy of floating sleepers at rail joints by measuring vertical displacement and rail seat force at joints where floating sleepers has occurred.

In this study, we carried out measurements of wheel surface roughness and numerical analysis to quantitatively evaluate the relationship between the wheel surface roughness under normal use conditions and the bending moment of PC sleepers. The results were as follows: 1) A wheel flat with the dip of about 0.5 mm had been measured. 2) Compared to the roughness spectrum of a wheel without a wheel flat, the wheel flat increased the roughness level at spatial frequencies of 10 to 100 m^-1, and the irregularity level was up to about 10 dB higher at a spatial frequency of 35 m^-1. 3) Numerical analysis also revealed that if the flat length of the wheel flat is up to about 10 mm, it has almost no effect on the response of the PC sleepers.

While mechanization of inspections using vehicle-mounted equipment has been progressing to determine the condition of track components in general track sections, mechanization of inspections in turnout sections has not progressed due to the complexity of the track structure and operational problems of vehicles. In order to replace the visual inspection of turnout sections to mechanized inspection, we have developed a prototype of a hand-held inspection device using multiple cameras and a viewer application to display the results.

Today, condition monitoring systems (CMS) of point machines and failure detection and diagnosis methods using CMS data are also proposed and then in used. Most of all proposed methods are targeted switch malfunctions by changing gradually such as friction force on bed plate, motor current, and displacement of lock rod. However, another mode of malfunctions happening suddenly are also available, but there is no failure detection and diagnosis method applying such mode of malfunctions. Therefore, we developed a failure detection method covering suddenly happened failure peculiarly broken of inner structure of electric point machine using CMS data, based on failure analysis focused on physical relation between point machine parts.

Railway operators often manage point machines through periodic inspections and condition monitoring systems. Since periodic inspections are labor-intensive, if some of the inspection items could be replaced by a condition monitoring system, maintenance work could be more efficient. In this study, we will confirm whether a condition monitoring system can determine the difference in electric current between normal and simulated abnormal conditions of point machines. We will also confirm whether the electric current at the time of conversion failure can be used to detect foreign matter in the point machine. Through the above, the homogeneity of periodic inspections and condition monitoring systems, and the superiority of condition monitoring systems over periodic inspections will be evaluated, and a direction for reviewing the inspection system will be presented.

In order to identify the cause of failure of the front rod, which connecting the tip of tongue rails, we attempted to elucidate the relationship between the state of stress and extensional adjustments state. First, we measure the strain in each section of the front rod while changing the state of extensional adjustments. The measurement found that the strain increased whether the front rod was extended or shrunk. Also, the strain around the long hole of the L-shaped fitting was particularly affected. Next, the stress in case of the tongue rail was forced to stick rail was analyzed using a finite element model of the point section of railroad switch. The results showed the same tendency as in the measurement, and it was found that a high stress region existed from the inner surface of the long hole of the L-shaped fitting to the outer surface.

Breakage of a front rod by environmental conditions of turnout and switch devices have been one of the issues of maintenance of signalling devices. In this paper, we investigated the relationship between environmental conditions and front rod strain by the failure history of railway operators, on-site survey, and measurement tests at switches when a train passes through. As a result, we confirmed that the impact, when the wheel passes over the joint with difference of elevation at the end of the tongue rail, affects the strain and stress fluctuations on the front rod. Based on these results, we also proposed inspection methods of front rods.

Extension of the front rod is often conducted to decrease the gap between the toe of the tongue rail and the stock rail in case that the gap becomes large when finishing the switching operation. There is a possibility that the adjustment leads to the fatigue of the “hinged lug”, which is a part of the railroad switch components. In our previous study, it was shown that extension of the front rod alters the path of force transmission by using multi-body dynamics simulation. In this study, we validated the simulation results through the experimental measurement. The result shows that the extension of the front rod increases the force between front rod and tongue rail and decreases that between switch rod and tongue rail. The experimental result shows good agreement with the simulation results.

In some Japanese railway operators, the maintenance standard values for track irregularity at turnouts on conventional railways, where trains pass through the main line of turnout at a speed of 120km/h (referred to in this study as “high speed type turnouts”), are managed with stricter values compared to those for turnouts other than high speed type turnouts. These values have been empirically determined based on past running tests. In this study, we built a simulation model using the three-dimensional dynamic FEM which enabled the quantitative evaluation of the effects of track irregularity on track components damage to set new maintenance values based on technical evidence in high speed type turnouts. Furthermore, using the simulation model, case studies on track irregularity were conducted to clarify its effect quantitatively.

In rigid crossings of turnouts laid on composite sleepers with direct fixation of the Shinkansen trains has large dents on nose rails compared to those of ballasted turnouts. The authors focused on the difference in the dynamic load depending on the support condition, and to make depth of dents on nose rails in composite sleepers on direct fixation turnout equal to that for a ballast turnout, developed tie plate for rigid crossings with elastic support. With the conventional tie plate, it is compatible and replaceable.

Assist suit have been introduced and are being researched and developed as a work support device in industrial fields such as logistics, construction, agriculture, and electrical installation. This time, focusing on this assist suit, we report on the development of an assistive suit that keeps upper arms raised to reduce the burden and improves the workability of maintenance work on overhead contact line.

Overhead contact line fittings may loosen due to overhead contact line vibration when a train passes by. We use anti-looseness nuts, periodically retighten bolts at a predetermined force to prevent loosening, and check the fastening condition of the fittings by close-up inspections. These tasks require a great of labor. Conventional contact line fittings loosen when the frictional force between the bolt’s seat surface and the fittings is lost. Therefore, we have developed a new fastening structure for overhead contact line fittings that does not loosen due to overhead line vibration by utilizing L/R bolts with an anti-looseness mechanism that does not rely on friction to fasten bolts.

Rail grinding is an essential maintenance way to remove rail surface defects and restore the profile of railhead. However, the amount of metal removal decreases against rails with a flat cross-sectional profile, which increases maintenance frequency and maintenance costs of railway track. To improve the quality and efficiency of rail grinding, this study proposes a quantitative index for evaluating cross-sectional profile of railhead and a simplified method to determine a grinding pattern based on this index.

Finally, the proposed method has been confirmed to be applicable to on-board measurement of rail profile.

This study investigated the possibility of omitting rail grinding after rail milling work. Under the condition without grinding or with grinding after the milling of rail surface, a material condition of the rail, a remaining rail surface roughness and a rolling noise were measured to confirm the effect of omitting rail grinding. The results suggest that the omission of rail grinding is unlikely to have a negative effect on the rail material. On the other hand, the rolling noise after the rail milling without rail grinding tended to increase due to the remaining rail surface roughness. Further investigations will be carried out to confirm how long it takes for the rail to return to its the pre-work condition.

Wheel profile automatic measurement device was developed to keep ride comfort, perform wheel turning at the appropriate time, and manage wheels at a higher level. This device was designed to be highly accurate and compact enough to be installed in the main track for high frequency measurements. The accuracy of this device was confirmed to be adequate compared to the conventional method. Endurance test was conducted on this device to resolve various problems. Utilization of this device will result in lower costs and a higher level of wheel management.

We investigated the reinforcing method in order to prevent the breakage of thermite welds due to solidification cracking for rails. A finite element analysis model of the welds was developed and validated by comparing the results of loading analysis with an experiment of static bending tests. Using the analytical model, we evaluated the reduction effect of bending stress at the bottom of the rail by the reinforcing method and found that the conventional reinforcement fishplate for thermite welds reduced the bending stress by about 10%, while the new reinforcement method reduced it by about 80%.

Using an acoustic emission (AE) method which utilizes the phenomenon of releasing the elastic energy stored inside as elastic waves when the material is deformed or fractured, full-scale dynamo bench testing of brake shoes for railway vehicles was carried out, and the correlation between the elastic waves and the friction characteristics of brake shoes was evaluated experimentally. In particular, we focused on the relationship between elastic waves and wear. In this paper, we report on the discovery of AE method for evaluating the amount of wear on brake shoes.

We have devised innovative anti-loosening bolts with a double thread-mechanism (denoted DTB-IIC) composed of coaxial single and multiple coarse threads. In this study, comparative Junker vibration loosening tests based on an ISO 16130 standard were conducted on two types of DTB-IICs. The amount of backlash δ between the inner multiple-thread nut and DTB-IIC bolt had a great effect on the initial drop of the bolt axial preload, and the DTB-IIC with a relatively small δ secured a residual axial load rate of ≥ 85%, which satisfied the rating-1 of good self-locking behavior in the ISO standard. A 3D FEM model was employed to simulate the initial loosening process in the Junker test, and the analytical results agreed well with the experimental ones by adjusting δ appropriately. Both experimental and analytical results indicated that the high loosening resistance of DTB-IIC was due to the synergistic effect of the interference mechanism of two types of nuts and the jammed locking state.

To verify the strength of a bogie frame, it is important to understand the stress rightly in the bogie frame. Currently, running tests have to be carried out with strain gauges sticked at various measurement locations on the bogie frame, which is both time consuming and costly. Previous methods for predicting the stress have been proposed using transfer functions or neural networks based on axle box acceleration measured during running. However, it has been difficult to predict the stresses at locations under the brake load, such as the brake lever supports, using acceleration of axle box. In this paper, we propose a new prediction method for predicting bogie frame stresses at locations under the brake load using brake commands.

Sufficient strength and stiffness are required for the bogie of a railway vehicle. In order to verify the stress in bogie frame during running, it is necessary to carry out a running test, but a running test of trains requires large amount of manpower and high cost. Therefore, it is difficult to carry out the running test every time the track conditions and running conditions change. In this paper, we proposed a method to predict the bogie frame stress from the measured acceleration of the axle box using the transfer function. The proposed prediction method of bogie frame stress was then verified for various bogie structures. In addition, the stresses were predicted for bogie of various structures, and were compared with measured stresses. As a result, it was found that the predicted stress was close to the measured stress for bogie of all structures. It was therefore shown that the proposed prediction method can be applied to bogie of various structures.

Rail grinding is employed for the maintenance and noise reduction of high-speed railway tracks. With the extension of the Hokuriku Shinkansen to Tsuruga Station scheduled for March 2024, extensive verification of rail grinding has been conducted. This study introduces a sequence that balances the efficiency of grinding operations with the preservation of the surrounding environment, while making micron-level adjustments.

Noise reduction along railway lines is important issues. Prediction of and countermeasures against noise around tunnel entrances have been studied. However, it is more difficult to estimate the effect of countermeasures against noise on the uneven ground surface around tunnel entrances than on flat terrain. In this study, based on the results of aerial laser surveying, an acoustic scale model of the uneven ground surface around the tunnel entrance was built, and the effect of the countermeasures against noise by raising the height of noise barrier and by the installation of sound-absorbing panel on the tunnel entrance hood was verified.

In this study, a numerical experiment was carried out using a finite element modelling, and the contribution of each member to structure-borne sound was quantitatively clarified. Specifically, the contribution of the overall value at the 25m point on a reinforced concrete (RC) rigid frame viaduct was 73% for the center slab, 10% for the soundproof wall, and 17% for the overhanging slab. In addition, the contribution of the RC rigid frame viaduct and the adjacent RC girders was 67% and 33% respectively, indicating that not only the rigid frame viaduct but also the RC girder may have a relatively large contribution to structure-borne sound along the railway line.

The noise attenuation level of exhaust silencer for Diesel Multiple Unit (DMU) were measured. The direct noise from the engine were also measured. The contribution of these noise sources are simulated. About the exhaust noise were simulated by FEM and CFD. Such simulations are compared to the measurement results.

To save energy consumption for the DC electric railway, regenerative braking energy between adjacent trains is very important. By adjusting the run curve of the train that receives RBE, we can effectively save energy. However, the energy that can be utilized between trains is constrained by many factors including motor efficiency, departure time interval, gradient, and so on. In this paper, we first introduce the composition and design method of energy-efficient operation for trains to utilize regenerative energy. Then, we discuss differences of the amount of regenerative energy utilization and suitable patterns of efficient train operations when depending on different vertical track profiles.

In this study, we have developed a driver advisory system using a speed estimation technique developed for freight trains aiming to ensure energy-saving and punctuality. The driver advisory system focuses on cruising driving operation by maintaining the planned time at each passage station. This paper presents the verification of the driver advisory system under various train conditions.

In the Shinkansen lines, snow shelters with slits linking neighboring tunnels are frequently built for snow disaster prevention. Furthermore, these shelters can act as countermeasures against micro-pressure waves by installing horizontal slits on their walls. However, the longitudinal pressure distribution inside the shelters remains unknown. Therefore, it is important to understand how to further accelerate the Shinkansen. In this study, a model experiment was conducted on pressure variations in a shelter with a slit. The experimental results clarified the characteristics of pressure distribution in the shelter.

Modal shifts to rail are attracting attention in the logistics sector as a way of addressing global warming and workforce shortages. Besides, maintaining transport is a challenge for passenger railways, particularly in rural areas. Logistics using passenger rail has the potential for railways to expand their use as well as for logistics to expand the range of logistics hubs and routes using passenger stations. The authors have surveyed the present state of logistics implementation by passenger railways in order to explore the development of logistics using passenger railways. The paper reports on the results of the analysis of these results, including the type of railways operating logistics and the type of logistics implementation, such as the establishment of own services or cooperation with other operators.

This study analyzes the stability of the railway system under the multi-type coupling operation scheme proposed by the authors as a near-future railway operation scheme, in which express and feeder (local) services are combined into a single train. The simulation analysis reveals that the proposed scheme does not differ significantly from the conventional scheme in terms of stability. It shows that both schemes exhibit the same delay propagation behavior in some cases, while in others, they show different behaviors. Furthermore, it was found that adding appropriate margins at characteristic points of the multi-type coupling scheme is necessary to improve stability.

On streetcars and other tram, collisions between vehicles are prevented by the driver's visual operation. On the other hand, about half of the number of collisions on tram from 2019 to 2024 are due to driver's assumptions and errors in judgment. Therefore, we hypothesized that the number of accidents could be reduced by installing devices to assist the driver. In this paper, we examine a method for detecting vehicles in front using LiDAR sensors in order to prevent collisions between vehicles. We have investigated the feasibility of this method using an actual vehicle and will report here.

Train delays during morning rush hours are a serious issue in the railways in metropolitan areas. In order to solve this problem，it is essential to set appropriate dwell times at each station. We have analyzed dwell times utilizing data obtained from load compensating devices of train-sets. We have established a method to estimate dwell times at each station by applying machine learning algorithm to this data. While further improvement in the estimation accuracy is required，the proposed algorithm is promising and expected to contribute to the proper setting of dwell times，helping to prevent train delays during morning rush hours.

This study develops a passenger OD flow estimation system in a railway station with utilizing security cameras. The proposed system consists of movie processing applying AI for automatic counting method of cross-sectional flow volume and OD flow estimation model based on cross-sectional flow volume data. This study demonstrates that the developed system can count cross-sectional flow volume with enough accuracy, as well as OD flow. Additionally, this paper demonstrates the reducing effect of cost of passenger flow investigation in comparison with an ordinary investigation method relaying on manual efforts.

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 have proposed the evaluation technique for the accuracy of train position detection using GNSS and evaluated it in the short term. We are considering that the accuracy evaluation not only in the short term but also in the long term is helpful for a preliminary evaluation.

The evaluation grid method is a method that aims to extract the cognitive structure, which is a mechanism of understanding and judgment unique to each person. In general, the evaluation grid method uses about 30 photographs as elements (objects to be investigated). However, in the evaluation of ride comfort, subjects need to memorize the vibration conditions for each different sensory condition. Therefore, in order to facilitate the ranking of the sensory evaluation when answering the questionnaire, the number of vibration conditions in one test condition was set to three, and four types of experiments were conducted to extract the evaluation structure in railroad ride comfort and to show the effect of this structure.

Various underground projects are being constructed in close proximity to existing underground structures such as subways in order to revitalize urban functions. In order to ensure the safety of the in-service facilities, it is necessary to accurately predict not only the impact of the rebound on the underground structures, but also the track gradient in subway tunnels. Currently, there are scattered cases of discrepancies between the preliminary impact prediction analysis values and the actual measured values. The main reason for this is that the interaction between the ground and structures has not been fully elucidated, and there are few examples of systematic analysis of this interaction. Therefore, the authors decided to conduct a number of systematic model experiments to elucidate the above interactions, while collecting data on several types of construction near the existing subway tunnels. This paper introduces a case study of the effects of ground rebounding caused by open-cut construction in close proximity to our existing subway tunnel, and describes the details of the model experiments that will be conducted in the future.

In order to optimize the inter-city travel network due to population decline, it is important to discuss the need for parallel transportation services. We proposed a model to calculate the optimal and equilibrium network shapes for this discussion. Fujita et al. (2022) showed that under conditions of large seasonal variations in demand, the coexistence of multiple parallel transportation modes is optimal. The newly proposed equilibrium model allows us to discuss the conditions including the behavior of airlines, rail operators, and travelers. Numerical simulations show that when multiple parallel modes are optimal, the consequences of each player's behavior also provide multiple modes.

A simple model to express long-distance travel demand across prefectural borders is the "gravity model." This model can explain the basic distribution of inter-prefectural travel based on the scale of origin and destination and the distance (travel cost). However, there are movements associated with business trips, such as the placement of headquarters and branches, which may not be adequately addressed by this model. So, what is the extent of this demand? In this study, we focus on the errors in the estimates of the gravity model concerning intercity flow based on mobile phone location data, attempting to clarify the characteristics of its spatiotemporal distribution.

Railway bogie frames are welded structures, and there are stress concentrations such as weld toes, internal defects, and weld metal in the weld joints. In this study, ten weld joints were selected from the cross-sectional observations of the joints in actual bogie frames where fatigue cracks had occurred, and stress analyses of them were conducted. As a result, the stress was the highest at the weld toes, which corresponded to the actual crack initiation location. This suggests that fatigue crack initiation is more affected by the local shape of the weld toe than by internal defects in the weld or the shape of the weld metal. In fatigue design of welded joints for railway bogie frames, it is appropriate to use edge type gauge stresses at weld toes and to use actual bogie frame models with an element size of 16 mm to obtain the edge type gauge stresses in FE analyses. Moreover, the cracks were thought not to propagate from the overlaps and weld cracks from calculation results based on the fracture mechanics.

The strength design of the bogie frames is based on JIS-E4207, and the load conditions in this standard are defined to reflect the various loads that are applied to bogie frames while the vehicle is running. However, it is not easy to determine the design load based on the stress generated by the dynamic behavior during running, and the design load is determined based on past experience and performance, but the theoretical basis is not clear. In this study, the final objective is to determine the design load taking into account the service stress of the bogie frame, and the relationship between the stress obtained by decomposing the service stress into each representative motion mode and the design load is clarified.

Bogie frames for railway vehicles are generally produced by assembling some components that are formed by pressed steel plates. Bogie frames are required to have sufficient strength due to their importance, and one of the contents to be considered for strength is the residual stress. Although there have had some investigations into residual stress on the sight of welds, there have been no investigations into the macro residual stress of bogie frames. In addition to that, the extent of the macro residual stress of bogie frames has not been reported. In this study, we conducted macro residual stress measurements of the bogie frame by sectioning method. The measurement results showed that the compressive macro residual stresses from 40 to 140 MPa were measured on the bottom plate of the side beam.

The inspection frequency for vehicles is determined based on deterioration or damage caused by distance or time. Distance-related factors typically include components such as bogie frames and wheel axles. Bogie frames are generally designed with a passenger load of 250% capacity. However, if the inspection frequency is evaluated assuming 250% capacity for the entire period, it is expected that the evaluation will be excessively conservative. Therefore, a more appropriate evaluation requires an understanding of the actual distribution of ridership (i.e., the distribution of vehicle mileage relative to passenger congestion levels). This study focused on estimating the vehicle mileage for each congestion level, which was calculated by time of day for a specific section in an urban area based on station congestion data. Additionally, the estimated results are discussed for each operating/running condition.

The residual fatigue life and fatigue crack growth rate of railway bogie frames are significantly affected by in-service stresses. Several studies have attempted to generalize the stress-frequency distributions obtained from running tests and predict fatigue life based on the modified Minor rule. However, in order to design safer railway bogies or to extend their inspection intervals, it is essential to predict the fatigue life at the design stage, before in-service stress data is available. This study aims to estimate the in-service stress-frequency distributions of railway bogie frames through a statistical analysis of previously collected running test data.

In the case of combination steel pillars for overhead contact line, strength calculations and eigenvalue analyses are carried out using the moment of inertia of the area that take into account the shape and arrangement of the main post, etc. However, since actual combination steel pillars are equipped with braces, conditions such as the dimensions of the braces are considered to affect the cross-sectional performance. Therefore, stress-deflection analysis using the finite element method was performed on a combination steel pillars model simulating these conditions to investigate the effects of various conditions on the cross-sectional performance.

To detect precursors to climbing derailments, an algorithm that analyzes data from gyro sensors and acceleration sensors on the bogie units using machine learning method is researched recently. For the development and validation of the detecting algorithm, data collection under climbing conditions are required with close to the real situation. In this study, the research group conducted a test bogie unit running test at low speed on an experimental track in the University of Tokyo. The bogie unit have weights loaded on the curvature inner side of it, intentionally reducing the wheel load on the outer wheels. This methodology allowed for the reproduction of flange climbing conditions, and data were collected accordingly. This paper introduces on the overview of this experiment, the reproduction results, and the initial analysis of the measured data from the bogie unit.

To improve the safety of Shinkansen services, we are developing a function to detect derailments using the vertical acceleration of the bogie frame obtained from existing bogie monitoring devices. First, to obtain basic data for determining derailments, derailment simulation tests were conducted using an actual bogie, and the acceleration levels occurring during normal operation were verified. Next, based on the obtained data and verification results, multiple detection algorithms were considered to distinguish between normal operation and derailment, with the aim of optimizing detection time and reducing the risk of undetected derailments. Finally, to evaluate the validity of the considered detection algorithm and verify the threshold value and duration, a monitoring run has been conducted with a vehicle equipped with the detection algorithm.

The increase in typhoons and heavy rainfall caused by climate change is having a serious impact on social infrastructure. In this study, we developed a high-precision system that estimates maximum instantaneous wind speeds at meteorological observation points by utilizing wind resource analysis for wind power plants, integrating meteorological forecasting technology, and spatially refining the data. This system has initiated a trial information service for railway operators to support operation control planning and is expected to enhance operational safety and efficiency.

Waterproof of the components that make up the railway signalling devices has been evaluated by the water spray test of JIS E 3017. The nozzle used in the water spray test standard for electrical equipment (JIS C 0920), which was the prototype for this test, has undergone structural changes to comply with international standards, making it difficult to procure new nozzles for water spray tests for signalling devices, which have been used since the standard was established. This paper reports the results of an experimental study on the amount of water sprayed, horizontal range, and range of water spraying to evaluate the impact on the water spray testing method for railway signalling devices when using a nozzle that specified in JIS C 0920.